Abstract: This research article describes the gas generator pyro-cartridge using gun propellant technology methods for fighter aircraft application. The emphasis of this work is to design and develop a gas generating device with pyro-cartridge using double base (DB) propellant to generate a high temperature and pressure gas. This device is utilised for dropping empty fuel tank in an emergency from military aircraft. A data acquisition system (DAS) is used to record time to maximum pressure, maximum pressure and time to half maximum pressure generated in a vented vessel (VV) for gas generator. Pyro-cartridge as a part of the gas generator creates a maximum pressure and time in the closed vessel (CV). This article also covers the qualification testing of gas generator. The performance parameters of pyro-cartridge devices such as ignition delay and maximum pressure are experimentally presented through the CV tests.
Abstract: This article outlines the ballistics of main seat ejection cartridges for aircraft application. The ballistics of main seat ejection cartridges plays a vital role during the ejection of the pilot in an emergency. The ballistic parameters such as maximum pressure, time to reach the maximum pressure, and time required to reach half the maximum pressure that responsible to the spinal injury of the pilot are assessed. Therefore, the evaluations of these parameters are very critical during various stages of development. Elaborate testing is carried out for main seat ejection cartridges on seat ejection tower (SET) at different operating temperatures considering physiological limits. As these trials are cumbersome in nature, a vented vessel (VV) testing facility is devised to lay down the performance parameters at hot and cold temperature conditions. Single base (SB) propellant having hepta-tubular configuration is selected as the main filling. Gun powder plays the role of a booster based on ballistic requirements. The evaluation methodology of various performance parameters of main seat ejection cartridges is explained in this paper. Physiological parameters such as maximum seat ejection velocity, acceleration, and rate of rising of acceleration are also experimentally determined on SET. All the parameters are observed well within physiological limits. This paper addresses the internal ballistic of main seat ejection cartridges, propellant selection, its calculation, and evaluation of various performance parameters for aircraft application.
Abstract: In present era, development of digital circuits, signal processors and other integrated circuits, magnitude comparators are challenged by large area and more power consumption. Comparator is most basic circuit that performs comparison. This paper presents a technique to design a two bit comparator which consumes less area and power. DSCH and MICROWIND version 3 are used to design the schematic and design the layout of the schematic, observe the performance parameters at different nanometer technologies respectively.
Abstract: A mathematical model to predict the performance parameters (thrusts, chamber pressures, fuel mass flow rates, mixture ratios, and regression rates during firing time) of hybrid rocket motor (HRM) is evaluated. The internal ballistic (IB) hybrid combustion model assumes that the solid fuel surface regression rate is controlled only by heat transfer (convective and radiative) from flame zone to solid fuel burning surface. A laboratory HRM is designed, manufactured, and tested for low thrust profile space missions (10-15 N) and for validating the mathematical model (computer program). The polymer material and gaseous oxidizer which are selected for this experimental work are polymethyle-methacrylate (PMMA) and polyethylene (PE) as solid fuel grain and gaseous oxygen (GO2) as oxidizer. The variation of various operational parameters with time is determined systematically and experimentally in firing of up to 20 seconds, and an average combustion efficiency of 95% of theory is achieved, which was the goal of these experiments. The comparison between recording fire data and predicting analytical parameters shows good agreement with the error that does not exceed 4.5% during all firing time. The current mathematical (computer) code can be used as a powerful tool for HRM analytical design parameters.
Abstract: In this paper, some performance parameters of a selected turbofan engine (JT9D) are analyzed. The engine is a high bypass turbofan engine which powers a wide-body aircraft and it produces 206 kN thrust force (thrust/weight ratio is 5.4). The objective parameters for the engine include calculation of power, specific fuel consumption, specific thrust, engine propulsive, thermal and overall efficiencies according to the various definitions given in the literature. Furthermore, in the case study, wasted energy from the exhaust is calculated at the maximum power setting (i.e. take off phase) for the engine.
Abstract: In this paper, a performance study was conducted to investigate single and dual-axis PV systems to generate electricity in five different sites in Kuwait. Relevant data were obtained by using two sources for validation purposes. A commercial software, PVsyst, was used to analyse the data, such as metrological data and other input parameters, and compute the performance parameters such as capacity factor (CF) and final yield (YF). The results indicated that single and dual-axis PV systems would be very beneficial to electricity generation in Kuwait as an alternative source to conventional power plants, especially with the increased demand over time. The ranges were also found to be competitive in comparison to leading countries using similar systems. A significant increase in CF and YF values around 24% and 28.8% was achieved related to the use of single and dual systems, respectively.
Abstract: A theoretical investigation on the effect of collector aspect ratio on the thermal performance of wavy finned absorber solar air heaters has been performed. For the constant collector area, the various performance parameters have been calculated for plane and wavy finned solar air heaters. It has been found that the performance of wavy finned solar air heater improved with the increase in the collector aspect ratio. The performance of wavy finned solar air heater has been found 30 percent higher than those of plane solar air heater. The obtained results for wavy fin solar air heaters are compared with the available experimental data of most common type solar air heaters.
Abstract: Due to increased pressure from global competitors, manufacturing organizations are switching over to lean philosophies from traditional mass production. Lean manufacturing is a manufacturing philosophy which focuses on elimination of various types of wastes and creates maximum value for the end customers. Lean thinking aims to produce high quality products and services at the lowest possible cost with maximum customer responsiveness. Indian Industry is facing lot of problems in this transformation from traditional mass production to lean production. Through this paper an attempt has been made to identify various lean implementation hurdles in Indian industries with the help of a structured survey. Identified hurdles are grouped with the help of factor analysis and rated by calculating descriptive statistics. To show the effect of lean implementation hurdles a hypothesis “Organizations having higher level of lean implementation hurdles will have poor (negative) performance” has been postulated and tested using correlation matrix between performance parameters of the organizations and identified hurdles. The findings of the paper will be helpful to prepare road map to identify and eradicate the lean implementation hurdles.
Abstract: The aim of this research paper is to conceptualize, discuss, analyze and propose alternate design methodologies for futuristic Black Box for flight safety. The proposal also includes global networking concepts for real time surveillance and monitoring of flight performance parameters including GPS parameters. It is expected that this proposal will serve as a failsafe real time diagnostic tool for accident investigation and location of debris in real time. In this paper, an attempt is made to improve the existing methods of flight data recording techniques and improve upon design considerations for futuristic FDR to overcome the trauma of not able to locate the block box. Since modern day communications and information technologies with large bandwidth are available coupled with faster computer processing techniques, the attempt made in this paper to develop a failsafe recording technique is feasible. Further data fusion/data warehousing technologies are available for exploitation.
Abstract: In this paper, autonomous performance of a small
manufactured unmanned helicopter is tried to be increased. For this
purpose, a small unmanned helicopter is manufactured in Erciyes
University, Faculty of Aeronautics and Astronautics. It is called as
ZANKA-Heli-I. For performance maximization, autopilot parameters
are determined via minimizing a cost function consisting of flight
performance parameters such as settling time, rise time, overshoot
during trajectory tracking. For this purpose, a stochastic optimization
method named as simultaneous perturbation stochastic approximation
is benefited. Using this approach, considerable autonomous
performance increase (around %23) is obtained.
Abstract: Biodiesel is widely investigated to solve the twin
problem of depletion of fossil fuel and environmental degradation.
The main objective of the present work is to compare performance,
emissions, and combustion characteristics of biodiesel derived from
cotton seed oil in a diesel engine with the baseline results of
petrodiesel fuel. Tests have been conducted on a single cylinder, four
stroke CIDI diesel engine with a speed of 1500 rpm and a fixed
compression ratio of 17.5 at different load conditions. The
performance parameters evaluated include brake thermal efficiency,
brake specific fuel consumption, brake power, indicated mean
effective pressure, mechanical efficiency, and exhaust gas
temperature. Regarding combustion study, cylinder pressure, rate of
pressure rise, net heat release rate, cumulative heat release, mean gas
temperature, mass fraction burned, and fuel line pressure were
evaluated. The emission parameters such as carbon monoxide, carbon
dioxide, un-burnt hydrocarbon, oxides of nitrogen, and smoke
opacity were also measured by a smoke meter and an exhaust gas
analyzer and compared with baseline results. The brake thermal
efficiency of cotton seed oil methyl ester (CSOME) was lower than
that of petrodiesel and brake specific fuel consumption was found to
be higher. However, biodiesel resulted in the reduction of carbon
dioxide, un-burnt hydrocarbon, and smoke opacity at the expense of
nitrogen oxides. Carbon monoxide emissions for biodiesel was higher
at maximum output power. It has been found that the combustion
characteristics of cotton seed oil methyl ester closely followed those
of standard petrodiesel. The experimental results suggested that
biodiesel derived from cotton seed oil could be used as a good
substitute to petrodiesel fuel in a conventional diesel without any
modification.
Abstract: Concrete is strong in compression however weak in
tension. The tensile strength as well as ductile property of concrete
could be improved by addition of short dispersed fibers. Polyethylene
terephthalate (PET) fiber obtained from hand cutting or mechanical
slitting of plastic sheets generally used as discrete reinforcement in
substitution of steel fiber. PET fiber obtained from the former process
is in the form of straight slit sheet pattern that impart weaker
mechanical bonding behavior in the concrete matrix. To improve the
limitation of straight slit sheet fiber the present study considered two
additional geometry of fiber namely (a) flattened end slit sheet and
(b) deformed slit sheet. The mix for plain concrete was design for a
compressive strength of 25 MPa at 28 days curing time with a watercement
ratio of 0.5. Cylindrical and beam specimens with 0.5% fibers
volume fraction and without fibers were cast to investigate the
influence of geometry on the mechanical properties of concrete. The
performance parameters mainly studied include flexural strength,
splitting tensile strength, compressive strength and ultrasonic pulse
velocity (UPV). Test results show that geometry of fiber has a
marginal effect on the workability of concrete. However, it plays a
significant role in achieving a good compressive and tensile strength
of concrete. Further, significant improvement in term of flexural and
energy dissipation capacity were observed from other fibers as
compared to the straight slit sheet pattern. Also, the inclusion of PET
fiber improved the ability in absorbing energy in the post-cracking
state of the specimen as well as no significant porous structures.
Abstract: A novel design technique employing CMOS Current
Feedback Operational Amplifier (CFOA) is presented. The feature of
consumption very low power in designing pseudo-OTA is used to
decreasing the total power consumption of the proposed CFOA. This
design approach applies pseudo-OTA as input stage cascaded with
buffer stage. Moreover, the DC input offset voltage and harmonic
distortion (HD) of the proposed CFOA are very low values compared
with the conventional CMOS CFOA due to the symmetrical input
stage. P-Spice simulation results are obtained using 0.18μm MIETEC
CMOS process parameters and supply voltage of ±1.2V, 50μA
biasing current. The p-spice simulation shows excellent improvement
of the proposed CFOA over existing CMOS CFOA. Some of these
performance parameters, for example, are DC gain of 62. dB, openloop
gain bandwidth product of 108 MHz, slew rate (SR+) of
+71.2V/μS, THD of -63dB and DC consumption power (PC) of
2mW.
Abstract: In the present study, RBF neural networks were used
for predicting the performance and emission parameters of a
biodiesel engine. Engine experiments were carried out in a 4 stroke
diesel engine using blends of diesel and Honge methyl ester as the
fuel. Performance parameters like BTE, BSEC, Tex and emissions
from the engine were measured. These experimental results were
used for ANN modeling.
RBF center initialization was done by random selection and by
using Clustered techniques. Network was trained by using fixed and
varying widths for the RBF units. It was observed that RBF results
were having a good agreement with the experimental results.
Networks trained by using clustering technique gave better results
than using random selection of centers in terms of reduced MRE and
increased prediction accuracy. The average MRE for the performance
parameters was 3.25% with the prediction accuracy of 98% and for
emissions it was 10.4% with a prediction accuracy of 80%.
Abstract: Parabolic solar trough systems have seen limited
deployments in cold northern climates as they are more suitable for
electricity production in southern latitudes. A numerical dynamic
model is developed to simulate troughs installed in cold climates and
validated using a parabolic solar trough facility in Winnipeg. The
model is developed in Simulink and will be utilized to simulate a trigeneration
system for heating, cooling and electricity generation in
remote northern communities. The main objective of this simulation
is to obtain operational data of solar troughs in cold climates and use
the model to determine ways to improve the economics and address
cold weather issues.
In this paper the validated Simulink model is applied to simulate a
solar assisted absorption cooling system along with electricity
generation using Organic Rankine Cycle (ORC) and thermal storage.
A control strategy is employed to distribute the heated oil from solar
collectors among the above three systems considering the
temperature requirements. This modelling provides dynamic
performance results using measured meteorological data recorded
every minute at the solar facility location. The purpose of this
modeling approach is to accurately predict system performance at
each time step considering the solar radiation fluctuations due to
passing clouds. Optimization of the controller in cold temperatures is
another goal of the simulation to for example minimize heat losses in
winter when energy demand is high and solar resources are low.
The solar absorption cooling is modeled to use the generated heat
from the solar trough system and provide cooling in summer for a
greenhouse which is located next to the solar field.
The results of the simulation are presented for a summer day in
Winnipeg which includes comparison of performance parameters of
the absorption cooling and ORC systems at different heat transfer
fluid (HTF) temperatures.
Abstract: In this paper, the transient device performance analysis
of n-type Gate Inside JunctionLess Transistor (GI-JLT) has been
evaluated. 3-D Bohm Quantum Potential (BQP) transport device
simulation has been used to evaluate the delay and power dissipation
performance. GI-JLT has a number of desirable device parameters
such as reduced propagation delay, dynamic power dissipation,
power and delay product, intrinsic gate delay and energy delay
product as compared to Gate-all-around transistors GAA-JLT. In
addition to this, various other device performance parameters namely,
on/off current ratio, short channel effects (SCE), transconductance
Generation Factor (TGF) and unity gain cut-off frequency (fT ) and
subthreshold slope (SS) of the GI-JLT and GAA-JLT have been
analyzed and compared. GI-JLT shows better device performance
characteristics than GAA-JLT for low power and high frequency
applications, because of its larger gate electrostatic control on the
device operation.
Abstract: A single-phase closed thermosyphon has been
fabricated and experimented to utilize solar energy for water heating.
The working fluid of the closed thermosyphon is heated at the flatplate
collector and the hot water goes to the water tank due to density
gradient caused by temperature differences. This experimental work
was done using insulated water tank and insulated connecting pipe
between the tank and the flat-plate collector. From the collected data,
performance parameters such as instantaneous collector efficiency
and heat removal factor are calculated. In this study, the effects of
glazing were also observed. The water temperature rise and the
maximum instantaneous efficiency obtained from this experiment
with glazing using insulated water tank and insulated connecting pipe
are 17°C in a period of 5 hours and 60% respectively. Whereas the
water temperature rise and the maximum instantaneous efficiency
obtained from this experiment with glazing using non-insulated water
tank and non-insulated connecting pipe are 14°C in a period of 5
hours and 39% respectively.
Abstract: The purpose of this work is to optimize a Switched Reluctance Motor (SRM) for an automotive application, specifically for a fully electric car. A new optimization approach is proposed. This unique approach transforms automotive customer requirements into an optimization problem, based on sound knowledge of a SRM theory. The approach combines an analytical and a finite element analysis of the motor to quantify static nonlinear and dynamic performance parameters, as phase currents and motor torque maps, an output power and power losses in order to find the optimal motor as close to the reality as possible, within reasonable time. The new approach yields the optimal motor which is competitive with other types of already proposed motors for automotive applications. This distinctive approach can also be used to optimize other types of electrical motors, when parts specifically related to the SRM are adjusted accordingly.
Abstract: The Montreal protocol and Kyoto protocol underlined the need of substitution of CFC’s and HCFC’s due to their adverse impact on atmospheric ozone layer which protects earth from U.V rays. The CFCs have been entirely ruled out since 1995 and a long-term basis HCFCs must be replaced by 2020. All this events motivated HFC refrigerants which are harmless to ozone layer. In this paper thermodynamic analysis of cascade refrigeration system has been done using three different refrigerant pairs R13-R12, R290-R23, and R404A-R23. Effect of various operating parameters i.e. evaporator temperature, condenser temperature, temperature difference in cascade condenser and low temperature cycle condenser temperature on performance parameters viz. COP, exergetic efficiency and refrigerant mass flow ratio have been studied. Thermodynamic analysis shows that out of three refrigerant pairs R12-R13, R290-R23 and R404A-R23 the COP of R290-R23 refrigerant pair is highest.
Abstract: The modern energy-efficient houses are often founded on a thermal insulation (TI) layer placed under the building’s RC foundation slab.The purpose of the paper is to identify the potential problems of the buildings founded on TI layer from the seismic point of view. The two main goals of the study were to assess the seismic behavior of such buildings, and to search for the critical structural parameters affecting the response of the superstructure as well as of the extruded polystyrene (XPS) layer. As a test building a multi-storeyed RC frame structure with and without the XPS layer under the foundation slab has been investigated utilizing nonlinear dynamic (time-history) and static (pushover) analyses. The structural response has been investigated with reference to the following performance parameters: i) Building’s lateral roof displacements, ii) Edge compressive and shear strains of the XPS, iii) Horizontal accelerations of the superstructure, iv) Plastic hinge patterns of the superstructure, v) Part of the foundation in compression, and vi) Deformations of the underlying soil and vertical displacements of the foundation slab (i.e. identifying the potential uplift). The results have shown that in the case of higher and stiff structures lying on firm soil the use of XPS under the foundation slab might induce amplified structural peak responses compared to the building models without XPS under the foundation slab. The analysis has revealed that the superstructure as well as the XPS response is substantially affected by the stiffness of the foundation slab.