ISSE HYDERABAD CHAPTER
Abstracts
Systems Engineering Role and Importance in Weapon Development
G. Naresh Kumar
Defence industry is involved in numerous weapon development programs to meet the requirement armed forces. Aerospace platforms, underwater systems and other major systems often comprise a large number of interacting subsystems that have to collectively satisfy a set of specified goals. Moreover, these requirements often evolve throughout the development cycle and improvements during the life of the system. Additionally, these may be contradicting requirements. Systems Engineering (SE) provides designers the capability to manage complex relationships
within a subsystem design and across the rest of the subsystems. Systems
engineering ensures
that, the primary system complies with the most challenging requirements from
concept development through production and then the extended service life.
The purpose of this article is to share my experience in Systems
engineering during the design and development phase of weapon systems. The
concept of connectivity diagram is used here.
System Engineering Challenges in
Development of LOX-Isro sene Booster Stage for Future Launch Vehicle of ISRO
B Suresh Babu, Reji Joseph, and S
Jagannathan
Liquid Propulsion Systems Centre (LPSC) of
ISRO is pioneer in the design and development of liquid propulsive stages. It
has undertaken development of Semi-Cryogenic propulsion stage, which will be
the largest liquid stage developed so far. The stage with Liquid Oxygen (LOX)
and Kerosene based fuel (Isro sene) as its main propellants helps to enhance the
payload of GSLV MkIII launcher to beyond 5 tones. Design of liquid propulsion
stage is complex as it involves components like valves, regulators, flow
control devices, functional modules and control sub systems. A typical liquid
propulsion stage will have more than 25 sub-systems, each having its own set of
components, operating conditions and specification. Systems engineering plays
major role in development and realization of such complex Liquid Propellant
stages of launch vehicle. Major challenges that are anticipated during
mechanical design and development of the LOX-Isro sene (semi-cryogenic) stage
are handling large temperature gradients between propellant tanks, its unique
storage as well as assembly requirements and management of thermal stresses in
adjacent structures. It also warranted the need of combining the system
engineering practices followed for Cryogenic and Earth Storable liquid
propellant stages, without compromising on the sub system performance. The
Semi-Cryogenic stage being developed is planned as a replacement of core booster
stage of GSLV-MkIII, heaviest launcher developed by ISRO so far. Though this
method reduces development time and cost, it induced additional constraints on
the stage development. System engineering practices are utilized for complete
assessment of stage systems and for finalization of system configuration with
an objective of reduction in development time, cost and without any changes in
the remaining systems of the launch vehicle. This paper presents the relevance
of systems engineering for launch vehicle development, complexities involved in
design and development of Semi-Cryogenic liquid propellant stage and solution
strategies implemented for overcoming the design challenges with selected
examples.
Design
and mathematical modeling of Fuel Feed System for Dual Fuel Scramjet
Kesava
Vishnu G, Vishnu Suresh Nair, Anoop V M, Arun
G S, Kuldeep Singh Naruka
A Fuel Feed System (FFS) is designed to supply fuels for a Dual
Fuel Scramjet engine. The system design is carried out based on the operational
requirements of flow rate, pressure, duration within the envelope constraints.
The scramjet engine consists of an effervescent injector with liquid
hydrocarbon as the main fuel. Gaseous Hydrogen is used for pilot ignition and
for emulsifying the liquid hydrocarbon. Hydrogen gas for both the requirements
are met through a single source and supply system. The liquid hydrocarbon
storage system consists of a standalone propellant tank with positive expulsion
device and cavitating venturis. Mathematical modelling is done on the system and
from the model outputs, the operational efficacy of the feed system throughout
the flight duration is ensured.
Monte Carlo Based Tolerance Analysis
of Sub-systems in Cryogenic Umbilicals
Jishnu T R, Vaibhav Amalak Ahire, Hemendra
Kumar Dhurandher, Dilip V, Sathis Kumar B, Alex A
The space reforms in India have opened up
the space market and in turn opened a window of opportunity for entry of
private players into the market. The vision of Indian Space Research
Organisation (ISRO) is to change the supply-based model of space sector to
demand-based model. To capture the foreign and domestic launch vehicle market,
the building costs of the launch vehicle needs to be optimised. The concepts of
lean manufacturing, design optimisation, topology optimisation etc., need to be
brought in at the design phase to achieve this while mass manufacturing is
planned for the launch vehicles. Dimensional Tolerance analysis have been
extensively used in mass manufacturing industries to model how the deviations
in part level are propagating to assembly. Though computationally expensive,
Monte Carlo method is one of the most common tools used for this analysis.
Based on a Probability Distribution Function (PDF), number of part dimensions
are generated within the tolerance band and the distribution of assembly
parameter is evaluated based on geometrical dependency. The sensitivity of
dimensional/ geometrical tolerances on assembly critical parameters can be
effectively studied by this method. Fluid Control Components in launch vehicles
employ a large number of fabricated parts and the assembly of these elements to
form a sub-assembly will bring out huge number of critical assembly parameters.
Not achieving these specifications can cause hardware rejection, thus
increasing the cost of production & delay in project schedule. This study
presents the tolerance analysis of certain sub-assemblies used in cryogenic
umbilical systems employed in ISRO. The sensitivity analysis of geometrical
parameters also presented. These results can of paramount importance to fine tune
the design & fabrication drawings at the time of mass manufacturing of
parts.
Novel Design of a Joint with Translational Freedom for Propellant Tank
Anti-Slosh Baffle System
Deepak K*,
Jayesh P, Ravi Ranjan Kumar and Reji Joseph
Launch vehicles stages are fuelled by different propellants at ambient
and cryogenic temperatures, which are stored in propellant tanks. The
propellant tanks are subjected to pressure, structural, aerodynamic, thermal
and slosh loads. Anti-slosh baffles are provided inside propellant tanks to
provide adequate slosh suppression. These baffles are mounted inside tanks
within limited space, along with other internal systems. The pressure and
structural loads induce axial dilation of propellant tanks and rotation of end
rings. Axial freedom at baffle mounting joints is required to reduce the
mechanical reaction loads at the joints caused by tank deformation, under
pressure and axial loads. The anti-slosh baffle joints should have sufficient
freedom to manage such tank dilations, which is achieved by providing
translational freedom to the joints, without compromising the structural
integrity. Conventional joints with translational freedom have complex joining
procedure, demand space and access requirement. Only limited joining techniques
like bolting and riveting can be employed in anti-slosh baffle systems to meet
the assembly and integration requirements. The assembly of anti-slosh baffle
sub-assemblies inside propellant tanks is easier with joints comprising of rivets. This paper presents a novel design of
a riveted joint with translational freedom for anti-slosh baffles inside a
propellant tank. The design is validated with a quasi-static tensile test and
the qualified joint is adopted in engineering of the system for flight.
Modelling and
Dimensional Analysis of Spring Loaded Pressure Regulator for Performance
Prediction and Characterization
Rishabh
Garg, Kailas S. Kuhite, Sunil S., D. Venkittaraman, Alex A.
The successful performance of a typical launch vehicle
depends on fault free and reliable performance of different propulsion stages
which uses various fluid control systems to control flow, pressure and
direction of propellant and pressurant. Liquid propulsion stages require almost
constant propellant tank pressure to maintain desired propellant flow into
engines and to provide a positive pump suction head to avoid cavitation. In
addition, these stages require constant pressure command gas source to operate
engine propellant flow control valves, gas generator valves, purge valves etc.
Pressure regulator is a variable-area pressure reduction valve, which provides
constant outlet pressure at its downstream, irrespective of variations in inlet
pressure and flow demand. In active
Pressurisation systems, the design of pressure regulator is complex due to the
large band of inlet pressure variation at high flow rate demand. A non-linear
dynamic mathematical model of pressure regulator is required for predicting the
performance in the specified working conditions with respect to initial
transients, temperature effects, variation in input/ output conditions,
inherent oscillations etc. The model is also effective to carry out post-flight
analysis by simulating anomalies seen during ground tests and during flight. The
upper stage of PSLV uses liquid pressure-fed engines which has two-stage
regulated pressurisation system to maintain constant tank pressure with
regulators in series. First rough regulator regulates high pressure GHe stored
in gas bottle to intermediate pressure and then precision second regulator
regulates to final required tank pressure. A non-linear and 1D time-domain
mathematical model of high pressure regulator simulating transients and working
range was made using AMESim software
and validated with experiment results. One of the anomalous observation in
regulator during ground testing was studied with this model. Later these
observations were confirmed by NDT techniques on the hardware. Paper presents
the details of the model and parametric study conducted on the regulator. The
validation of model with test results and characterization of the model to
recreate the anomaly is also presented.
Numerical Study of the Liquid Oxygen Draining in a Spinning Tank with Baffles for Hybrid-Propulsion Rocket
Anant Singhal, Deepak K. Agarwal, T. John Tharakan, S. Sunil Kum
Computational Fluid Dynamics (CFD) study of
liquid oxygen draining in a spinning tank with and without baffles is carried
out for hybrid propulsion rocket. The effect of tank spinning and the presence
of baffles on the vortex formation and unusable propellant mass is brought out
in this work. The interface of the draining propellant is captured using the
Volume of Fluid (VOF) framework while the motion of baffles is simulated
through mesh motion technique. Initially, analysis of liquid oxygen draining is
carried out in a stationary tank without baffles. It is found that that a
vortex is formed in the tank and gas entry in the feed line happens at 21s
resulting in unusable propellant of 1.9kg. Subsequent analysis of liquid
draining in a spinning tank without baffles shows that gas enters into the feed
line earlier as compared to the stationary tank. Finally, the analysis is
carried out for propellant draining in spinning tank with baffles. It is found
that the momentum imparted by the baffles to the draining fluid increases the
unusable propellant mass further compared to tank without baffle.
Numerical Study on De-Icing Of Aeroplane Wing Using
Piezoelectric Materials
K
GuruBrahmam, Prof. M Chandra Sekhar Reddy,
and Prof. T Ramamohan Rao
The focus of the present
investigation is to de-ice an airfoil wing using vibration induced by
piezoelectric material. We selected symmetrical airfoil (NACA0015) for the
numerical simulation. Airfoil is designed using solid works as airfoil data.
Piezo electric patches and ice layer are designed and assembled to the airfoil
wing using solid works. The final model is imported into ANSYS. Modal analysis
is carried out for extraction of frequencies and mode shapes. Harmonic analysis
is carried out for maximum shear stress. The results of these simulations
allowed optimizing the positioning of the patches and angle of piezo on the
structure and the optimal excitation voltage for the piezoelectric patches.
Results are presented in the form of tabular data and digital photographs
Realization
of Integrated Data Acquisition for Testing
of Human Rated GAGANYAAN
Vikas Engine
Priya Esther DR,
Vineeth Marella, Ethamukkala BalaKrishna,
Vinoth B, Gilbert Chandra,
Murugananda Bhaskaran
The L110 VIKAS engine certification testing for the
Gaganyaan program, comprised of three long duration qualification tests and
four short-duration off nominal tests. The Test Article (The GAGANYAAN Vikas
Engine) measurement system comprises of Process Measurements namely Pressure,
Temperature, Strain, Speed, and Vibration. Erstwhile Test Article measurement
system used individual Signal Conditioning Amplifiers, Excitation Power
supplies, and the Data Acquisition system using The PCI Extension for
Instrumentation (PXI- Data Acquisition system ) The revamping of the Test
Article Measurement System in the
Principal Test Stand control centre - was carried out by inducting the state-of art
Integrated Data Acquisition systems(IDAS) with inbuilt excitation modules,
Sigma delta ADCs thereby replacing the old signal conditioning modules and
excitation modules. The induction of the IDAS was pivotal in ensuring accurate
and precise measurements required in the GAGANYAAN ground testing. The paper
elucidates the arduous Testing of the IDAS and the various Hot Test results of
the GAGANYAAN Engine Test Series.
Roll damping
analysis of crew escape vehicle with grid fins at subsonic and transonic Mach
numbers
M Jathaveda,
Kunal Garg,P
Balasubramanian, Harish A, G Vidya
Crew Escape Vehicle (CEV) is a
man rated vehicle, which is used to eject the crew module from main rocket in
an emergency situation so that the crew can be saved. Grid fins are employed in
this vehicle for aerodynamic stabilization. Aerodynamic characterization is
quite crucial for mission simulation and studies. Static and dynamic
aerodynamic coefficients govern aerodynamic behavior among which roll damping
derivative represents aerodynamic damping due to roll motion. Roll damping
derivatives are obtained from wind tunnel tests for range of Mach numbers but
sparse data is available due to cost overhead hence CFD has been employed for
same. Forced oscillation technique using CFD++ software has been validated for
Basic Finner configuration and same has been applied for CEV in current
studies. Roll damping derivative are obtained for CEV and compared with wind
tunnel results. Current studies have been carried out for subsonic and
transonic Mach number but can be extended to supersonic Mach number.
Synthetic Aperture Radar Data
Quality Characterization and Calibration Analysis of EOS-04
S. SriSudha, S. JayaBharathi,
S. HariPriya and B. Santhisree
EOS4 satellite is launched on
14th Feb 2022 by PSLV C-52 in sun Synchronous polar Orbit of 529Km. This paper
presents the data products quality evaluation of Earth Observation Satellite
-04 in terms of Geometric and Radiometric aspects by using Data Quality
Evaluation Software Modules. Geometric and Radiometric Quality Parameters were
estimated periodically using Level-1 and Level-2 data products of Strip Map and
Scan SAR Imaging modes. The parameters like Background to Peak Ratio (BPRatio),
Integrated Side Lobe ratio (ISLR), Peak to Side Lobe ratio (PSLR), Radar Cross
Section (RCS) of the Corner Reflector (CR) and geometric resolution are
computed and validated against the specification periodically using Level-1
Single Look Complex data to validate the SAR-antenna performance. The
parameters like sigma naught, speckle index, radiometric resolution,
signal-to-noise ratio are computed over Amazon forest to monitor and validate
the radiometric stability using Level-1 Single Look Complex products. For the
estimation of Polarimetric Quality Parameters, the Level-1 Single Look Complex
Datasets acquired over Cal-Val sites is used.
Emitter Geolocation from Near-Space
Platform Using 3D TDOA
Suman
Agrawal
The space between the maximum altitude at
which a modern plane can fly and the minimum altitude at which a satellite can
operate is known to as near space. A free balloon, an airship, and an unmanned
aerial (UAV) vehicle are some of the aircraft in the near space. The
near-space platform has the ability to identify far-off emitters in a large
area due to its unique feature of having a large coverage area, full-time, and
large-scaled. Near-space has drawn a lot of attention recently since it is
below the ionosphere and doesn't experience ionospheric scintillations, which
can significantly degrade RF communications and navigation performance. The
focus of this paper is to compute geolocation in various scenarios. Geolocation
is computed in two dimension (2D) using hybrid AOA/TDOA/FDOA measurements from
ground/ship based sensors at varying emitter distances and geolocation accuracy
is calculated using Root Mean Square Error (RMSE) and Circular Error of
Probability (CEP50). Further, geolocation is computed in three
dimension (3D) using TDOA measurements from ground/ship based sensors at
varying emitter altitudes and geolocation accuracy is computed in terms of
total joint covariance matrix (Standard Deviation) from all receivers. The
results of above geolocation accuracy are compared with geolocation from
near-space based sensors placed at varying altitudes while the emitter is
placed on ground/ship based platform using 3D TDOA measurements. TDOA
measurements are obtained by cross-correlating the signal received at all the
sensors. The performance for all the scenarios are demonstrated through modelling
and simulations. Experimental results in varied scenarios and specifically
near-space platforms will help in designing of systems as per the required
accuracy and in future visualizing the accuracies from space based platforms.
Performance Observation of IRNSS in Terms of Receiver
Geometry and Position Accuracy over Hyderabad Region
R.
Anil Kumar, P. Naveen Kumar
The Indian
Regional Navigation Satellite System (IRNSS) is a satellite navigation system
developed by the Indian Space Research Organization (ISRO), using the
frequencies of the L5 and S1 bands. The IRNSS system is independent of GPS. It is used for position,
velocity and timing (PVT) services over the Indian region and surrounding
coverage area of 1500 km. The positional accuracy of IRNSS system suffers from
many sources of errors. To achieve better accuracy, combination of different
navigation systems is required. This paper presents the detailed analysis of
IRNSS satellite visibility, dilution of precision (DOP) and signal strength
under open sky. The effect of satellite geometry on position accuracy and
performance of IRNSS is presented. From the results, it is observed that the
combined IRNSS/GPS hybrid mode of operation of dual frequency receiver
measurements gives better accuracy compare to hybrid mode of operation using
single frequency measurements.
High Resolution Spectral
Analysis of Pressure Oscillations in Large Segmented Solid Rocket Motors
Kali Prasad KVASN, Dr. Sankaran
S and Anuj Nigam
In the present work various
methods of Spectral Analysis are analysed and implemented to get high
resolution spectrogram results to find frequencies of pressure oscillation
varying with time for a Large Segmented Solid Rocket Motor. The analysis was
conducted using MATLAB software package R2022a. Validation of the implemented
code has been made using a theoretical signal which was generated using MATLAB
program to closely resemble the variation in frequency and amplitude to Large
segmented solid rocket motor pressure signal data. Pressure Oscillations in
Large Segmented Solid Rocket Motors are caused by vortex shedding at frontal
thermal protections (inhibitors) and acoustic response upon from impingement of
vortices on surfaces like other inhibitors or rocket motor nozzle. This
coupling along with change in internal diameter of rocket motor due to
fuel-grain burning causes continuous variation in frequency of pressure
oscillations in motor. The conventional Fast-Fourier Transform algorithm used
in spectral analysis is unable to produce high resolution results to be able to
identify this continuous frequency variation in pressure oscillations.
Predicting the shear properties in
S-glass epoxy composite by finite element analysis
Pullela Ramalakshmi, Kongari Akshaya, and
Pinninti Ravinder Reddy
S-glass
is technically significant glass fiber. It has high stiffness, strength and
softening point. This fiber finds application in light weight armor. In the present work, S-glass reinforced composite is
considered to examine the shear properties by finite element analysis. To
examine the shear properties, the dimension of the specimen described in ASTM C
1425 is selected with variation in the sample thickness and notch separation.
The shear properties will be examined at the sample thickness of 10 mm and the
notch separation will be varied from 1 mm to 5 mm. The
shear properties examined from this work will be useful in design data
considerations.
Visualization
of Spokes Mode in a Hall Effect Thruster
Souradeep
Roy Choudhury, Samvram Sahu, Vara Prasad Kella and Vikash Kumar
The present work investigates the
dynamics of rotating spokes modes in a Hall Effect Thruster (HET) also known as
a Stationary Plasma Thruster (SPT). Understanding these modes is important to
investigate electron transport phenomena which constitute power losses for the
thruster. Furthermore, the results may be inputs to future simulation studies.
In this paper, post processing technique of raw images to visualize the spoke
modes is presented. Images of an 85 mm mean diameter SPT anode channel,
operated at 783 W at a pressure of 
were acquired via a High Speed Camera. The
images so obtained were extremely saturated with the cathode intensity while
the anode channel intensity was dominated by its DC component. Automated image
processing techniques were then applied. In this process, the images were
normalized with respect to the camera specifications and the cathode and anode
were segmented from the anode channel image frames using Otsu’s thresholding.
The normalized and extracted regions are subjected to a string of
post-processing involving normalization by mean image and removal of noise and
the DC component. This resulted in an improved contrast as well as removal of
saturation in the images due to the cathode, enabling one to focus exclusively
on spokes modes.
Experimental study of magnetic field
effects on SPT performance
Vara
Prasad K, Umesh R Kadhane, M Rafi, Anish A and Anooja S
Stationary Plasma Thrusters (SPT), also known as
Hall Effect Thrusters (HET) are one of the matured electric propulsion
thrusters used by different space agencies for spacecraft orbit raising and
NSSK operations. Higher Isp and higher reliability offered by these
thrusters make them standout in this category. ISRO has taken steps to develop
SPTs of various power levels to cater the Indian space programme. Magnetic
field profile is the heart of these SPTs, which will confine the electrons for
better ionization of propellant and helps in creating strong electric field to
accelerate the charged ions. The magnetic field strength affects the ceramic
liner erosion which in turn determines the life of the thruster. In this study,
the effects of magnetic field on thruster performance are examined
experimentally. The SPT used in these experiments is a 85mm mean diameter
thruster operated at 700W discharge power. The test facility used is a
cylindrical vacuum chamber with 1.6m diameter and 4m length, equipped with
roughing pumps, turbo molecular pump, cryo pump and Xenon cold heads. The
vacuum level in the chamber during the testing of the thruster was 2.6x10-5
mbar of Xenon. Discharge current, discharge current oscillations and plasma plume
profile were monitored at different magnetic fields. The magnetic field is
tuned by varying the magnet coil currents.
The 3D profiles of the magnetic field were measured using an automated
3D magnetic field mapper system. Discharge current oscillations are acquired
through a high sampling oscilloscope and plume angle estimated based on
measurements with Faraday probe. In this paper the performance of SPT in terms
of discharge current oscillations and plume angle is presented with different
peak magnetic field strengths from 78G to 171G. The mean discharge current,
divergence angle are lower at 143G. High frequency modes are observed to be
exit at 0.9A and 0.7A of coil current corresponds to magnetic field of 100G and
78G.
Studies to investigate the effect of
feed line orientation on chill-down performance of cryogenic feed lines
Venkatesh N, Anant Singhal, Deepak Kumar Agarwal, ASalih, S Sunil Kumar
In
Cryogenic Systems, chill down of transfer or feed lines to a temperature very
close to that of the cryogen is to be achieved first prior to its admission at
rated flow rate for steady state operation and this is achieved by admitting
the cryogen at a low flow rate. This chill down process is very complex and is
highly sensitive to parameters like feed line orientation, distribution of
thermal mass associated with the system, mass flux of the cryogen, heat in-leak
etc.. In the present study, experiments are conceived to address the influence
of feed line orientation on chill down performance. A set-up is realized
employing a foam insulated test section and experiments are conducted using
Liquid Nitrogen. Tests are performed in horizontal and different upward as well
as downward orientation. Chill down performance is analysed using the measured
surface temperature data. It is observed to be very sensitive to feed line
orientation, faster with upward inclination and slower with downward
orientation. Wall heat flux is estimated using experimental data and heat flux
pattern for different feed line orientation is studied. Heat flux pattern at
bottom locations is observed to be not affected significantly by feed line
orientation. Whereas heat flux pattern at top locations is distinctly different
in tests with upward orientation. CFD simulation is also done, as a typical
case, for 45o downward inclination, using ANSYS software to capture
the flow pattern and wall temperature profile. Flow structure is well captured
and very good match is seen with the experimental data for the bottom wall
temperature profile.
Terminal Phase Guidance design for an
Anti-Ship Bank-To-Turn (BTT) Cruise Missile
N. Akilandeswari, Mallikarjun. Bangi, K.K. Mangrulkar, and G. Naresh
Kumar
In this paper, a different approach guidance technique is evolved by
generating an angle, to guide an anti-ship cruise missile in terminal phase.
The present work focuses to model and simulate a guidance scheme for terminal
phase of an anti-ship Bank to Turn (BTT) cruise missile. The targeted ships are
relatively slow compared to missile speeds. The modified guidance law of Pure
Pursuit and Proportional Navigation (PN) in terms of course angle is
implemented for stationary as well as moving targets in the lateral plane. The
longitudinal guidance is achieved by computing the commanded altitude as a
function of range to go.
Aerodynamic Parameter Estimation of RLV From Telemeter
Sensor Output
Ashwin Chandar O R, A K Sarkar, R Mukesh
An important applications of System Identification in
aerospace science is aerodynamic parameter estimation from flight data. Though
plenty of literature exist for aircraft on this topic, scanty for flight
vehicles. An unified methodology of aerodynamic parameter estimation of flight
vehicles is developed using Estimation Before Modeling technique under
practical constraints of limited external measurements and mild or no
excitations during flight. This technique has been extensively validated using
flight data of different types of flight vehicles. In this paper, aerodynamic
parameter estimation of Reusable Launch Vehicle during descend phase of flight
is presented. Available onboard measurements are very noisy and also telemeter
accelerometer and gyro signals are with intermittently missing data. Here no
external measurements are available and it underwent maneuver only along pitch
plane, considered for aerodynamic parameter estimation. Under these practical
constraints, aerodynamic moment coefficients have been estimated and compared
with preflight values in present research.
Terrain Referenced Navigation Technique Using Correlation Algorithms for
Cruise Vehicle
Suresh Mamidipalli, Mallikarjun Bangi and G. Naresh Kumar
The Cruise
vehicle is guided by an Inertial Navigation Systems (INS) and Satellite
Navigation (SatNav). Where INS provides very accurate and reliable solution for
navigation, but gyroscope and accelerometers errors accumulate with time, and
accordingly navigation errors also grow w.r.to time leading to very high
Position drifts for long duration missions. While in SatNav performance is poor
due to the signal interference and jamming. The solution to these problems
leads to an introduction of another device to perform precise measurements of
the vehicle's geographical position along its flight path. TERCOM is a well
approved navigation technique which deals with terrain elevation. TERCOM
compares the measured elevation value and on-board stored elevation value using
correlation algorithm. A TERCOM system is a self-contained and provides
positional fixes to cruise vehicle, aircraft, and drones. TERCOM is the only
fix-taking system that can operate autonomously in a RF/ SatNav denied
scenarios. TERCOM can be used in both tactical and strategic systems and
operates under ECM (electronic countermeasures) conditions and provides
day/night, all weather capability in low altitude terrain following scenarios.
This paper presents correlation algorithm and its performance evaluation in the
Western Ghats of India.
Impact of Deblurring on Image
matching algorithms
Vaddi Chandra Sekhar, Boda Nehru, D
Penchalaiah, Akula Naresh, G Naresh Kumar, Abhijit Bhattacharyya
Motion blur can have a significant impact on the performance of image
matching tasks, particularly when using feature-based matching algorithms like
SIFT (Scale-Invariant Feature Transform) or SURF (Speeded Up Robust Features).
In this work we explore the impact of image deblurring on image matching
algorithms. For our work we chose one classical algorithm SIFT and one Neural
network model D2NET. For deblurring the images we used the state of the art
deblurGAN model. It is observed that Image matching has significantly improved
on the deblurred images compared to the blurred images as observed from the
precision recall curves.
Computational Analysis of Horizontal
Axis Wind Turbine Blade NACA 63(4)221
Uma Maheshwat Vanamala, Purna VisishtaBattu
Wind energy is one of the most sustainable sources of renewable energy. The fast technological development in the wind industry and availability of multi megawatt sized horizontal axis wind turbines has further led to the promotion of wind power utilization globally. The paper presents work on NACA 63(4)-221 aerofoil profile is taken which is redesigned horizontal axis wind turbine blade (HAWT) for VESTAS RRB V27-225 kW. In a HAWT, aerofoil blades are very essential parts. Forces for lift and drag on the blade play an important role in the aerodynamic efficiency of aerofoil. CFD analysis on the aerofoil blade of wind turbine is carried out and the effect of angle of attack and Reynolds number on performance of the NACA 63(4)-221 aerofoil blade is presented. The ratio of coefficient of lift to coefficient of drag (Cl/Cd) is calculated. Maximum Cl/Cd values are observed at Angle of Attack 6o degrees.
Self-reliance in salvo launch of an Article
Ashish
Kumar Gupta
Defence
activities that can be carried out from underwater platforms are torpedo,
underwater mines and submarine launched missile and so on. This paper focuses
on the activities when articles are launched from submersible platforms. In
real-time scenario, after firing of an article, it is ensured that maximum
damage is caused to adversary and that the operation must be finished in
prerequisite duration and the mobile launcher should flee from that area in a
short period. It details the factors that are considered while implementing the
schemes for salvo launch in terms of fault tolerance, automated sequences,
system modular design and various communication protocols. This system has been
successfully implemented and tested for warfare activities.
Experimental Investigation on the
Interaction of Supersonic Plume with Launch Pad Structure
B.N.V Sai Aditya, M. Deepthi, G. Venkatesh,
T. Srinivas Reddy, S. Sankaran
With the advent of increased launch frequency, ISRO is planning to meet
the demand by augmenting the existing launch pad at Sriharikota using an
innovative scheme of launch vehicle integration and transfer sequence. Under
this project, the integrated launch vehicle will be transferred on Mobile
Launch Pedestal (MLP) from the integration facility to the First launch pad on
a rail track. This rail track will cross the Jet Deflector Duct (JDD) with a
rail track span of 7.5m. The rail track will be supported on the girder, which
will be subjected to severe thermal environment generated due to the
interaction of hot supersonic jet from C-D nozzle with a 9 0cant
angle, through the launch pedestal cut-out during launch vehicle lift-off. In
order to design the rail track girder beam, cold and launch pad measurements
are initiated to study this thermal & flow related problem and map the
extent of interaction of hot supersonic jet on the launch pad structure,
simulating the rail beam structure. Pressure, temperature, heat flux and flow
visualization results are presented and discussed in this paper. From the flow
visualization results and launch pad measurements it is understood that there
is no direct impingement of supersonic jet on the launch pad structure, resulting
in a benign condition of flow parameters.
Characterization of a Pressurized
Convoluted Metallic Flexible Hose under Large Bending Angles for Systems
Engineering of High Pressure Swiveling Thruster
B Kartik Surendra, Sourabh Karmarkar, B
Suresh Babu, Reji Joseph, Jagannathan S
Metallic flexible hoses with convolutions and wire braiding are used
for various of applications in the aerospace systems. One such application is
for carrying a high temperature, high pressure gas for a roll control system of
a core liquid stage of a launch vehicle. In this application, the flexible hose
connects a fixed hot gas inlet rigid line to a swiveling thruster. The flexible
hose undergoes bending in a single plane about an axis perpendicular to its
length and located in between the two ends. The estimation of torque required
to bend the pressurized flexible hose is needed for finalizing the design
specifications of the torque motor used for swiveling the thruster. As the
flexible hose is fabricated by mechanical/hydroforming process which induces
plastic strain and the uncertainties associated with braiding stiffness makes accurate
analytical modeling difficult. An experimental approach is adopted in this
study for estimating the bending torques required for different bend angles
with a specifically engineered unconventional and unique experimental set up.
This study presents the results of bending tests performed on a convoluted
metallic flexible hose with an internal pressure of 50 bar and assembled under
stretched and un-stretched conditions for different offset distances from one
of the ends. The roll thruster swivels by an angle of 
o, which subjects the flexible hose to relatively large bending angles.
A nonlinear variation of bending torque with bending angle was observed in this
study. When the flexible hose is assembled in an un-stretched condition, a
snapping behavior is observed during bending, in which the curvature developed
in one direction suddenly shifts to the other side. A significant reduction in
the snapping behavior was observed upon assembly in a stretched condition. The
maximum torque required for bending the flexible hose to the desired swivel
angle is estimated for different configurations of the experimental setup.
Torque estimated from the tests is used for selecting the torque motor and for
detailed systems engineering of the roll control system.
Development
of Shock Test Fixture for a Heavy Rocket Valve
This article presents the technical challenges faced during the shock
test of 84kg cryogenic valve for a liquid rocket engine and the counter
measures implemented to tackle the issue. Aerospace valves are generally
subjected to shock test in three orthogonal directional axes (x, y & z) as
part of qualification test program to simulate the sudden accelerations
occurring during transportation. The main challenge was posed due to high mass
(153kg) and asymmetry of the Equipment Under Test (EUT) with respect to centre
of gravity (CG) of the valve. The shock level for the test is 50g force in
semi-sinusoidal waveform for duration of 10millisecond. The CG of EUT is
located using 3D CAD model. The CG offset varied from 37mm to 94mm from shaker
axis depending on mounting plane (XY, YZ & XZ) due to asymmetry of the
EUT. The large mass, offset of CG from
the vertical axis and the shock level called for a higher capacity shaker with
a large displacement withstanding higher overturn moment. To counter this
issue, a Shock Test Fixture (STF) is designed to keep the CG of EUT within a
radius of 10mm from the axis of the available shaker of 290kN capacity. The STF
is developed keeping the cumulative mass of EUT within the shaker limit of
230kg and acts as an intermediate test fixture between EUT and shaker table.
The shock test of EUT is conducted successfully for the first time in the 290kN
shaker using the newly developed STF. This approach shows that similar design
methodology can be followed for the optimum utilization of available resources
in an economical way.
Design and development of sealing mechanism for
Gaseous medium cryogenic safety valve for ISRO Launch vehicle application
Arun Baby, Gaurav Sharma, Sunil S, D Venkittaraman,
and A Alex
Safety valves are most commonly used in aerospace, oil and chemical industry to prevent over pressurization of systems leading to loss of man, material and machine. Usage of cryogenic valves is very common in various launch vehicles worldwide as well as within ISRO. In aerospace application, safety valves are used to prevent over pressurization of either propellant tanks or other subsystem’s like command system, roll control system and/or orbit control and stabilization systems.
Inverted operation relief valves offer advantage of relatively higher sealing stress at operating condition in comparison to direct operation relief valves. Leakage observations in relief valves are very common and also a primary cause of failure. In contrast to pneumatically operated ON/OFF valves, seat stress in relief valves are limited and further reduces close to operating conditions.
Mechanism of sealing in relief valves could be either hard on hard or soft on hard type of sealing. Owing to better leak tightness, soft on hard type of sealing is mostly preferred for cryogenic gaseous application. Soft materials like polycarbonate, Teflon &Kel-F has good sealing characteristics, whereas the mechanical strength of these soft materials is inferior to metals and cannot be used as structural member inside valves. Lesser mechanical strength of these non-metals requires sufficient metallic support to increase structural integrity of valve seats. Soft seats are inserted into these metallic poppets after dipping in liquid nitrogen to achieve required amount of dimensional shrink followed by seat pressing and crimping using special purpose dies. Specially crimped soft seats by plastic deformation of metals helps in retaining soft seats inside metallic poppet. Ductile materials like Aluminum Bronze and AISI 321 are commonly used as poppet materials.
The process of poppet sub assembly crimping is a highly skilled operation and carried out after ensuring low temperature clearances, mating point radius/chamfer and smooth edges for die travel. This paper discusses the crimping of a cryogenic safety valve poppet sub-assembly with soft seat as polycarbonate and metallic poppet made up of Aluminum Bronze. Observations during crimping and issues related to ineffective crimping along with NDT evidence are discussed in detail. Crimping process qualification and advanced NDT screening of every crimped poppet subassembly is also presented in this paper. A comparison of load requirement during crimping by analytical approach against UTM load applied is made and a good match is observed.
Multifractal Detrended Fluctuation
Analysis for Onset of Combustion Instability in Liquid Rocket Engines
Varghese Mathew Thannickal, T. John
Tharakan, S. R. Chakravarthy
Combustion instability is a potentially destructive phenomenon that
leads to time and cost overruns in a rocket engine development project. Active
control in open loop or closed loop configurations is being investigated to
suppress combustion instability. The active control strategies can be made more
effective if there is a forewarning of impending instability. In this work,
multifractal detrended fluctuation analysis (MFDFA) is examined as a technique
to provide forewarning of instability in liquid engines. The method is based on
the decomposition of the chamber pressure data of the engine into singularity
exponents and dimensions at different fractal orders. These parameters can be
parametrically combined to generate the fractal spectrum. The fractal spectrum
has a definite shape characterized by its height, width, differential height
and apex location. The evolution of the multifractal spectrum characteristics
is known to yield information on the onset of instability based on lab level
experiments. The applicability of MFDFA to investigate the onset of instability
in full-scale engines assessed in this work. Typical earth storable and
cryogenic engines are used as case studies.
Reflection and Review of Fuel
Delivery Systems
Sadan Kanchanapalli and Ramanathan
Subramanian
In attempting to keep up with emissions and efficiency forces, the fuel
method employed in contemporary automobiles has changed a lot over the past few
decades. Fuel solution has been in for decades, and electronic fuel injection
was applied widely on European automobiles beginning in 1980s. Today, all
automobiles in the world have fuel injection schemes in place for emission
control. This paper compares the different fuel delivery systems, explains the
working and types of fuel delivery systems currently in use in automobiles and
discusses some problems present in the current fuel delivery systems.
Fault
Management of Guidance and Control System for Aerospace Vehicles
M. Reshma Gopal, O. R. Ashwin Chandar,
and Dr. P. Koti Lakshmi,
Aerospace vehicles generally are safety-critical
systems and they rely on sophisticated control systems. For an aerospace system
to be fully reliable and highly safe, it requires to have the features of fault
detection and diagnosis. In case of malfunction of the control actuators or
sensors or other components, a conventional feedback control design may not
meet the system requirement and may cause catastrophic failure. It therefore
becomes a necessity to design fault tolerating control system design to improve
the reliability of the system and maintain the overall system stability. The
fault tolerance is achieved by fault detection and diagnosis and isolation of
the fault. After the fault is recognized, the reconfiguration is carried out by
means of redundancy on-board and the flight operation is continued. This paper
gives the design of highly reliable flight control systems by employing fault
detection and reconfiguration on-board by hardware and analytical redundancy
techniques.
Immunotronics
inspired Novel Self Repairing Finite State Machine for RISC-V based Processor
Deepanjali. S
and Noor Mahammad Balasubramanian. P G Venkat Reddy
RISC-V processor is an open-source Instruction-set
architecture (ISA), used to implement soft-core processors or System-on- Chip
(SoC) in multiple FPGA and embedded systems. The increasing reduction in the
size of these devices has increased the probability of upsets towards radiation
environments. These errors are called Single Event Upset (SEU) which can cause
functional failures in mission-critical components like control circuits. Hence
reliability through self- healing mechanisms has become an essential
characteristic of digital systems. Motivations from the human system to resist
the invasion of harmful foreign bodies have been incorporated into the field of
fault-tolerant electronics under the research area called Immunotronics. Our
proposed system introduces self-repairing capabilities for the RISC-V control
circuit through Immunotronics. The results are summarized as a proof-of-
concept to verify the SEU-Tolerance.
Electro Cardiogram (ECG) Monitoring using Internet of
Things and predict future in advance using artificial intelligence
Dr. G. Sasikala G. Satya Krishna
An IoT Based Electro cardiogram monitoring system will continue monitor
the patient health condition related to heart and update immediately if any
abnormality found in the patient health viz Wi-Fi to things peak application in
mobile phone. The doctor located at remote location will monitor the situation
accordingly and take appropriate decision, so that life time of the patient
will be increased. In addition to it we may predict the health condition in
advance using artificial intelligence. Based on patient health data we may
produce trainee set and compare it with test set to estimate the variation in
the health status and based on variation observed it may alert the doctor to
indicate the early deterioration of patient health condition, so that we may
arrest the growth of disease in advance. Here we are using ECG sensor to take
the patient health data and it will be processed using Arduino board, Arduino
microcontroller will compare the patient ECG with threshold limits, if it
crosses lower or upper value it may alert the doctor. After processing it will
transfer data to smart phone using Wi-Fi. Patient data will be continuously
logged and it will be taken as trainee set and compared it with available test
set to estimate the patient health condition in advance.
[Keywords:
ECG Sensor, ARDUINO UNO, WI - FI]
Real Time face Recognition System
using Jetson Nano
Vaddi Chandra Sekhar, D Penchalaiah,
G Naresh Kumar, Abhijit Bhattacharyya
This work aims to deploy an accurate face
recognition system on a low cost, portable and reliable hardware. Nvidia Jetson Nano is a small size, portable and powerful computer to
run Neural Networks. It uses an integrated 128-core Maxwell GPU for parallelization.
The total power consumed by the device is less than 10 watts. Face recognition
system consists of 2 steps, Face detection and Identification. Multi-Task
Cascaded Convolutional Neural Networks (MTCNN) Model has been used for Face
detection and VGG-Face has been used for Face Identification. The network is
trained on VGG-Face dataset which consists of 2.6 million face images of 2,622
people. The system has achieved real time performance of upto 4 fps with an
accuracy of 97.6% on Labeled Faces in the Wild (LFW) dataset.
SAR Image based Target Detection
& Identification using Deep Learning Model YOLOv7
B Nehru, Vaddi Chandra Sekhar, A Naresh, D
Penchalaiah, Abhijit Bhattacharya
In this paper we have implemented a Real Time
ship Target Detection on SAR Imagery Using deep learning model. Ship detection
is crucial to neutralize marine targets during combat scenario. SAR images
operate in all-weather conditions and all-day and independent of range. SAR
imagery based surveillance technology is particularly well suited for marine
surveillance. An Open-source SAR-ship dataset (HRSID) along with custom dataset
is used for detection and identification. The existing AI based methods of
detection (two stage object detectors) have proposed regions followed by extraction
of features. The speed of the process for these methods is slow for real-time
applications. Hence one stage detector, YOLOv7 with 415 convolution layers is
used for the application which will overcome constraints of the previous
methods. Mean Average Precision (mAP) of 78% @ 0.5 IOU is achieved for test
HRSID dataset and custom dataset. NVIDIA GPU (RTX A4000) hardware is used for
the training. The inference time of 8.2 milliseconds is achieved on NVIDIA RTX
A4000 GPU. Hence YOLOv7 is suitable for real time detection of military targets
on SAR images.
Adversarial
Machine learning Problems: Threats and Attacks
Revathi Lavanya Baggam,
V. ValliKumari, Gowri Shankar Wuriti
Machine
Learning is being extensively used in many wide range applications, as it shows
cases its technical breakthroughs. It also has proved its success by handling
complex scenarios and exhibited its capabilities very close to humans or even
much beyond the human ability. But, the research in recent times even prove
that machine learning models are being much more helpless to various kinds of
attacks, which in turn are compromising its security aspects of the models and
their applications. However, these type of attacks are cautious due to their
unexpected behavior of deep learning methods. In this survey, a systematic
analysis of the security issues of ML majorly focusing on the existing set of
attacks on ML systems, and their related defenses or the secure learning
approaches and the evaluation techniques. Inspite of keenly focusing on only
one type of approach or attack, this paper details about the various phases of
machine learning security starting from training phase to the testing phase.
Initially, this paper explains about the machine learning in the existence of
the adversaries present, and the reasons behind why the machine learning can be
easily attacked is analyzed. Later, the aspects with respective to machine
learning security are classified into majorly five sets namely: backdoors
present in the training set; theft to model; poisoning the training set;
sensitive training data recovery; adversarial example attacks. Also, the threat
models, various approaches to attack and the defense methods are analyzed.
Artificial
Intelligence based Electronic Warfare Systems: A Review
Kiran
Garje
Electronic Warfare is one of the most important
aspects of modern era Wars. Control of the spectrum, attack on adversary or
obstruct the enemy assault using Electromagnetic spectrum are some of functions
achieved as part of this warfare. Upcoming trends in AI indicate that, evolving
EW technology will have a revolutionizing influence on Armed Forces. AI based
algorithms can be very productive in various fields of EW viz. signal
processing for recognition and classification of targets, revelation of Jammers
and its characteristics for evolving suitable anti-jamming algorithms as well
as satellite signal monitoring and interception. Autonomous operation of EW systems
can also be realized using AI based approach. This paper gives an insight on
different aspects of EW, the usage of AI in EW systems and different techniques
that have been incorporated in conventional and Satellite based systems
Efficient Biometric Service Protocol for
Cloud Services
SwathiGowroju, S. SaiSatyanarayana Reddy, V. Swathi, R. Srinija, P. Rishika,
K Naveen Reddy
Cloud services will be ones that can be
accessed from a scattered cloud stockpiling worker rather than an on-site
server. These measured systems are operated by an outsider and allow users
online access to PC resources like systems administration or research. Cloud
computing is used to store data on cloud workers and to distribute processing
resources across the Internet. Due to
the pooling of resources, security and data insurance have become a crucial
area of concern in cloud computing. Cloud service providers use server farms
that are affected by information spillage to store and keep customer data. It
has been noted that several techniques have prioritised data protection while
ignoring privacy in the execution. Authentication helps to safeguard and
confirm a recipient's identity. We also offer a practical method for creating a
session key between two interacting parties that makes use of two biometric
models for secure message delivery. Finally, thorough tests and a comparison
analysis were used to determine the validity and usefulness of the suggested
remedy. Index Terms: Session key, cloud service access, biometric-based security,
and authentication.
Transfer-learning Enhanced Physics
Informed- Neural-Networks for Burgers’ Equation with High Reynolds’ Number
Nishant kumar, Manish Kr. Tiwari, Dr. P.S
Gurugubelli, Dr. Anil Kumar, Dr. M. Raghavendra Rao
We have attempted to solve
Burgers’ equation with Physics Informed Neural Networks (PINNs) using transfer
learning to address the difficulties in solving the equation with high Reynolds
number, that is, low values of kinematic viscosity. The obtained solutions are
compared with benchmark results from classical numerical methods, and it is
found that they are in close agreement. PINNs are also shown to accurately
model physical behaviour at low viscosities Transfer learning is shown to be a
great enhancement, particularly for low values of viscosity.
Driver
Drowsiness Monitoring System using Visual Behaviour and
Machine
Learning
Ambika Sahitya Batchu,
Madhuvani Patnam, and Goutham Karnati
One
of the leading factors in traffic accidents and fatalities is drowsy driving.
Hence, identifying driver weariness and related symptoms is a current research
subject. The majority of traditional approaches are either vehicle-, behavior-,
or physiological- based. Some approaches necessitate costly sensors and data
processing, while others are obtrusive and distracting to the driver. The
result of this work is the development of real-time, low-cost technology that
can identify drowsy driving. A webcam records the
video
in the designed system, and utilizing image processing algorithms, the driver's
face is recognized in each frame. Following the computation of the eye aspect
ratio, mouth opening ratio, drowsiness is determined by adaptive thresholding
based on the location of facial landmarks on the identified face. Moreover,
offline implementations of machine learning algorithms have been made. Based on
support vector machine classification, it was found that the sensitivity was
95.58% and the specificity was 100%.
Design and Implementation of Private Cloud
Infrastructure based on OpenStack for Strategic Organizations
M.
Swapna
Cloud technologies have become indispensable part of
organizations today. As an evolving paradigm for anytime, anywhere, cost
effective computing, cloud computing has attracted huge attention among
academics and industry. Many commercial companies are providing public cloud
solutions through internet. In public clouds, control over the entire cloud
infrastructure and the data hosted on it remains with the company providing
cloud solution. However, government and defense organizations require that
control over the cloud infrastructure and the hosted data is retained with
them. Hence private clouds are more suitable for strategic organizations.
This paper discusses design choices and challenges
involved in implementing an Open Stack based private cloud system for an
organization and customizing it for developing strategic applications while
saving recurrent costs and also providing data security. It also focuses on
automating the entire deployment with minimal manual work. As a case study for
PaaS, deep learning frameworks have been provided on cloud for training deep
learning models.
Design of High speed drive system for
rocket subsystem tests
Deepak Dinesh, Arun Kumar S, Remya KP, Harikumar K, Unnikrishnan Nair P, N. Jayan, Jose Paul
A high speed drive system driven by a radial turbine
was designed for testing high speed seals and bearings for rocket engine
turbopump. The drive system uses angular contact ceramic ball bearing pairs
with high speed capability for supporting the rotor and is lubricated using oil
mist lubrication method. The radial turbine design was carried out by 1-D mean
line method, to match the output of the available air supply from a screw
compressor. The preliminary design of
the radial turbine was analysed using CFD with CFX software. Structural
analysis was performed using ANSYS to ensure that stresses are benign at the
operating conditions. Rotordynamic
analysis of the rotating system was carried out with in-house FORTRAN code and
Campbell diagrams obtained showed that sub-critical operation was
achieved. The hardware was realised at
in house fabrication facility and balancing of the rotating system was carried
out to achieve minimum unbalance levels. The facility realization required for
the drive involved integrating procured pneumatically operated valves and
sensors with necessary instrumentation to the fabricated feed lines and test
bed. The testing of the high speed drive
was performed by remote operation and the test parameters were logged using a
data acquisition system. The testing
carried out achieved the targeted speed of greater than 60,000 rpm. Test Data showed minimal temperature rise at
the bearing location and large margins for the valve openings, suggesting that
even higher speeds are feasible. Post-test observation revealed good health of
the hardware.
Study on effect of vibration loading
of beam specimens on its dynamic characteristics
C Raja Kumaran, V Srinivasulu, V Venkata
Ramakrishna, Dr. T Srinivas Reddy, Dr. S Sankaran
Vibration fatigue is an important aspect to be
considered during the design and development of any structure or component
operating under vibration environment. Any component under fatigue may fail
abruptly below the yield or ultimate point, if it reaches its end of fatigue
life. Hence fatigue life estimation is very crucial for the safe operation of
any structure. In the case of launch vehicle/ launch pad structures, the jet
loads and acoustic loads experienced during the launch vehicle lift-off are
random in nature. Fatigue life estimation under random loads are complex
compared to harmonic loads. Several research works have been done in the area
of health monitoring and fatigue life estimation under sinusoidal and random
loading. In this work, an effort is made to understand the effect of fatigue
damage on the dynamic characteristics of a simple beam structure under harmonic
vibration loading and the prediction of residual life of a structure based on
the change in the dynamic characteristics is proposed. Cantilever beam
specimens of two different materials are considered in this study and the same
were made to fail under harmonic loading for the predetermined number of cycles
using an electro-dynamic shaker vibration testing setup. In this process, the variation
of dynamic parameters of the test beams with the number of cycles of loading
was monitored and the data is presented. Also, the initiation and propagation
of crack was monitored till the damage of the beam. Hence, from the variation
of natural frequency data, the residual life of the structure under study is
predicted.
Optimization of a stiffened interstage
structure of a launch vehicle using differential evolution algorithm in FEAST
Manash Kumar Bhadra, Shachindra Nath Sharma, Partha Ajit Surve and Vinod G
Optimization has become synonymous
to improvement in the context of design of launch vehicle structures. Problem
is challenging because it not only involves multiple variable but also multiple
objectives and constraints. The paper presents a method to optimize a stiffened
interstage structure of a launch vehicle using differential evolution
algorithm. The optimization was carried out to find the optimal number of
stiffeners required and the optimal geometry of the hat stiffener that will
minimize the hardware mass for specified axial compressive load, natural
frequency and the strength of the material. The proposed method is implemented
in a finite element analysis software named FEAST using Python based scripting
Multi optimization of Friction Stir Welding
of Aluminium AA 6061 Alloy using Grey based Taguchi method
Pranav Ravindrannair, K Kishore, P
Laxminarayana, U Ashok Kumar, F Hayat Khan
In this paper an experimental investigation
has been carried out to determine the optimal parametric setting during
Friction Stir Welding (FSW) of Aluminium AA 6061 alloy. The FSW process
parameters considered are welding speed, axial force and tool rotational speed
whereas the quality characteristics considered are tensile strength and tensile
elongation. The Taguchi method was applied in designing the experiments
involved in this study to optimize the welding parameters. Following the
Taguchi quality design, an L9 (3 3) orthogonal array was chosen to design the
experiment. The process parameters that were taken and their levels
incorporated in the array were chosen after conducting pilot experiments and
also through literature survey. The significant process parameters that affect
welding performance were determined by making use of Analysis of Variance (ANOVA)
and the F-test values along with the experimental results obtained. By
considering the significant parameters so obtained, the verification of the
improvement in the quality characteristics for the FSW of Aluminium AA 6061 was
done and the results obtained were found out to be an improvement over the
results obtained while using the original parameters (original setup). Apart
from the optimization of each process parameter taken individually, multi
response optimization has also been performed on both the process parameters
that have been mentioned above by making use of the Taguchi-Grey relational
analysis
Design
& Development of Four Wheel Steering Mechanism for Minimum Turning Radius:
A Case Study of CM Transportation Trolley
V Venkateswarlu
Dr. Jaiteerth R Joshi
The main intent of this research is to discuss the benefits,
applications, and implementation of four-wheel steering mechanism over
two-wheel steering mechanism. Based on a review of the relevant academic
journals, books, and textbooks, this investigation concludes that two-wheel
steering is more commonly used than four-wheel steering because of its lower
steering efficiency. Turning radius is decreased at low speeds, steering
reaction is enhanced, and vehicle stability is maximized with four-wheel
steering. Because to the limited space available in the magazines, the only
feasible alternative for designing a trolley to transport canisterized missiles
is to equip it with four-wheel steering. Explosion-proof prime movers are
required for usage on the CM transportation trolley, which moves CM containers
containing items from the magazine to the loading/unloading bay and back again.
To reduce the vehicle's turning radius using a four-wheel steering arrangement,
the rear wheels rotate counter to the front wheels. To accomplish the tighter
turn, a system composed of intermediate linkages and rotating components
transmits entire relative motion to the rear wheels. Safety margins were
determined by structural analysis performed in ANSYS 18, and the design and
development of the linkage mechanism and chassis frame was accomplished with
the help of CREO. The turning radius of the CM Transportation trolley was found
to be reduced by roughly 48% when compared with a two-wheel steering system
after a prototype was built and tested with a constant radius.
Computational Fire Safety Assessment
Studies in High Rise Assembly Buildings Using Fire Dynamic Simulator
Sanka SVD Sairam, V Vinodh, and T
Subbananthan
Indoors fires pose a significant threat in High
rise assembly buildings especially with a lot of working personnel in various
floors. In these type of buildings, fire protection, personnel and property
safety plays a key role. A study was carried out with Fire Dynamic Simulator
(FDS) for a created model of High rise assembly building with two different
types of fire scenario to understand the spread of fire and smoke at various
floors. Thus by depicting a proper adoption of fire & smoke detection
disposition considering these fire scenarios. The analysis was carried out by
choosing the right type of positioning the detection method at various floors
to minimize the response time.
Optimization of Process Parameters in Pulsed Current
GTA Welding Process on ASTM 106 Grade -B Steel Pipes Using Linear Regression
G Prakasham, L Siva Rama Krishna, J
Kandasamy
The
present research work aims to optimize the process parameters in the Pulsed
Current Gas Tungsten Arc Welding (PCGTAW) process by employing the Design of
Experiment (DOE) technique on ASTM 106 Grade- B Steel pipes. Taguchi
method-based orthogonal array, L9 for four factors Pulse current (PC),
Background Current (BC), Pulse Frequency (PF), and Pulse on time (PO) with
three levels are employed. The higher the better reaction is picked to decide
the ideal conditions for maximum ultimate tensile strength. The optimum values
are found to be 220 A pulse current, 100 A background current, 4 Hz pulse
frequency, and pulse on-time 50 %. ANOVA is implemented to gauge each factor's
% contribution. The outcomes indicate that background current and pulse current
are the significant process parameters to yield maximum ultimate tensile
strength. Regression equations are used to model ultimate tensile strength,
microhardness, and impact strength. Confirmation experiments are conducted to
validate the results.
The Radar Cross Section of Marine Vessels
G. SunilSriharsha, PC. Bhuvana, N. Harini, Mallikarjun. B, M. Jyoti, G.
Naresh Kumar
This paper focuses on the estimation of ship RCS
using High-Frequency Structure Simulator (HFSS). The results produced here have
been compared to the estimates available in the open literature of a Canadian
cargo ship named Teleost and also measured values. In this paper, the RCS of a
Canadian marine ship named “Teleost” is presented. RCS depends on various
parameters like shape, size, orientation, operating frequency and aspect angle.
Simulations using Finite Element Method (FEM) in Ansys HFSS software for
monostatic Radar Cross Section were made through 0.1MHz to 8MHz frequency. The results
of the proposed method are compared with the existing measured values and
simulated values available in open literature. The work is carried out using
PEC and steel as the dielectric material to analyse the monostatic RCS values,
and a broad comparison is made among previous values and the obtained values.
The results of this proposed method are more accurate when compared to the
previous works, and are very near to the measured values. The work is carried
out using Perfectly Electrical Conductor (PEC) and steel as the materials. The
simulations of these two materials are carried out individually, to analyze the
Monostatic RCS values.
Radar Cross Section modelling using Swerling
Probability Density Function for Target
Raveen Kumar K, Sabina Esther K, MMV Dhanumjaya
Rao, G Grahadurai
SDSC
SHAR, ISRO equipped with ground-based Precision Radars for tracking the launch
vehicles for range safety operations and trajectory computations. The Design of
Radar parameters, waveform generation and Receiver signal processing [4] always
appears to be challenging owing to the wide effects it can cause on the
performance of radars [3]. The radars under consideration are Tracking Radars,
intended for track Launch Vehicle. It is designed for skin mode and Transponder
mode operation which calls for accurate estimation of Signal strength to
achieve sufficient link margin for a target complex Radar Cross Section (RCS)
[6] at slant range.
In radar technology, scattering phenomenology is quantified by the
target parameter RCS, σ can be modelled as random process. Probability density
functions techniques are used to describe the target scattering and RCS
estimation. Receiver that employs an envelope detector followed by a threshold
decision technique [5]. The input to the receiver is composed of radar echo 
and additive zero mean white Gaussian noise 
, with variance
The input noise is
assumed to be spatially incoherent and uncorrelated with signal. The IF filter
output is a complex random variable that is composed of either noise alone or
noise plus target return signal. The noise quadrature components 
and 
are uncorrelated
zero mean low pass Gaussian noise with equal variance
. The Joint
Probability Density Functions of random variables is Rician PDF if target is
available or Rayleigh PDF if noise alone present. Variations in radar-target geometry [8],
target vibration, radar frequency, and polarization changes can lead to
variations in target RCS, resulting in fluctuating targets having Swerling
models [9 ] of target RCS fluctuation, The effect of these models on radar
detection, signal strength estimation for a given radar parameters are
considered.
Simulation of DSTATCOM for Distribution
Generation based system with various Algorithms
Ms. K. Bhavya, Dr. P.V.V. Rama Rao and Dr. L. Ravi Srinivas
The growth in protection devices in the field of power systems has been
rising from the preceding years which enlarge life span of the power system.
This paper aims at designing of various types of Custom Power Device (CPDs) for
stabilizing the system under abnormal conditions like sudden switching of
loads. One of the Custom Power Device Namely Distribution Static Compensator
(DSTATCOM) has been proposed for dealing with various power quality issues.
This work involves design of feedback control strategy with different
algorithms like BAT algorithm and ANT colony optimization algorithm for
controlling the parameters at the grid side and also at the load side. The
three-phase grid connected system has been tested with various conditions with
sudden occurrence of fault and also with sudden switching of various loads. The
assessment of performance of algorithms has been verified for various
parameters like PCC voltage, current, active power, reactive power and power
factor. The proposed system is simulated using MATLAB and results are also analysed.
Optimal
Placement and Sizing of DSTATCOM in Radial Distribution System Using
Gravitational Search Algorithm
U.
Chandra Rao, Rama Rao PVV, and N Sumathi
In order to reduce power losses and improve the
voltage profile of the Radial Distribution network, a Gravitational Search
Algorithm (GSA) is described in this work. A backward forward load flow
algorithm is taken as a base case and Loss Sensitivity Factors (LSF) are used
for identifying the candidate buses for D-STATCOM placement whereas the optical
allocation and sizing of D-STATCOM is done by using GSA. The proposed work has
been evaluated using the industry-standard IEEE 33-Bus Radial Distribution Test
network. The acquired results have been compared with the results obtained in
Base Case, Genetic Approach (GA), Immune Algorithm (IA), Harmony Search
Algorithm (HSA), Power Loss Index (PLI) technique, and Differential Evaluation
Algorithm in order to verify the usefulness of the proposed algorithm (DEA).
MATLAB software was used to run the simulation.
Multi Objective Optimization of
Process Parameters of Electro Discharge Machining On Nimonic 80A Using Grey
Relational Analysis
K.L. Uday Kiran, K. Saraswathamma, M. Rajesh
Abrasive powder-mixed electrode coated
electrical discharge machining (APMEC-EDM), a hybrid manufacturing process
involving the use of a dielectric fluid mixed with abrasive powder and coated
electrodes, combines the benefits of mechanical and thermal interactions. The
aim of this article is to use a new approach of performance evaluation, gray
relational analysis (GRA), to evaluate the effectiveness of optimizing multiple
performance characteristics of APMEC-EDM of Nimonic80A Super alloy. The
considered process parameter includes the five control factors namely pulse
current (A), pulse ON time (Ton), pulse off time (Toff), Inter Electrode gap
(mm) Aluminum powder concentration (g/L). The combination of L27 orthogonal
array design of experiment with GRA enables to determine the optimal parameters
for multiple responses. GRA is used to obtain a single performance index, gray
relational grade through gray relational coefficient to optimize the APMEC-EDM
process with lower tool wear rate, radial overcut, and higher material removal
rate.
Mitigation of Voltage Sag and Swell
in Smart Grid by using ANT-LION Intelligent Controller
D. ChandraSekhar, P.V. V Rama Rao and R.
Kiranmayi
In
the operational condition of an electrical power system, the need for proper utilization
with quality of utilization is primal. Where different types of quality
measures are deployed such as the linear filters and adaptive filters to
condition the current quality, a power flow controller is deployed to
compensate for the dissipation losses or fault tolerance. Where efforts are
made in enhancing power quality, efforts are also made in the utilization of
it. With the rapid and ever-increasing demand for power supply and rapid
increases in industrial and urbanization, the demand has exceeded the supply
capacity of all generation systems. To compensate for the demanded power
requirement, in addition to the existing power generation units, additional
subunits are added to the power system to compensate for the demanded supply.
Smart grids are designed as a cluster of various generation units and
consumption units. The demanded power is processed in these smart grids and
using a processing algorithm, these grids play a crucial part in adjusting the
power supply allocation to compensate for it. Here, the grid systems are either
designed for a concentric parameter or multi-objective monitoring in making a
decision. The issue is with the complexity in the parameter validation, where
multi-objective monitoring gives the benefit of accurate scheduling, the
complexity in parameter monitoring is higher.The
main objective of the proposed is weight-defined parameter monitoring of power
scheduling in multi-parameter monitoring, where the past approach of a
preference-based scheduler is to be developed with different intelligent
controller techniques like UNITED POWER FLOW CONTROLLER (UPFC) with ANT-LION
optimization (ALO) algorithm is proposed and
compared with ANFIS, Adaptive FLC, Reduced-order FL, FOPI, and FOFL. The
PQ issue in the system is helped by the UPFC device. A shunt active power
filter is used in series with an artificial neural network (ANN) with an
ALO-based controller to improve UPFC performance by allaying current and
voltage power quality (PQ) concerns. It proved
that our proposed system is best in smart grid applications using
MATLAB/Simulink