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The depletion of fossil fuels and their market inequality have led to the popularity of biofuels. Biofuels are a renewable energy source which can be a promising solution to the environmental issues created by fossil fuels. The emission of greenhouse gases and fluctuating prices of fossil fuels have put pressure on developing countries and small economic nations. Thus, one of the main concerns is the production of bio jet fuel from renewable resources, with a relatively low greenhouse gas life cycle and sustainability with affordable prices. Therefore, it is imperative to introduce and produce alternative aviation fuels generated from sustainable resources, specifically biofuels. In this study, we have reviewed alternative aviation fuels and their sources. We have also outlined the selection criteria for alternative aviation fuels along with discussing the sources that can be potentially used as fuel for the aviation industry.

This article concerned with the exergy analysis of different components of vapour compression refrigeration system and investigates the losses occurred in overall cycle as well as different stages of processes due to exergy destruction in the system based on evaporator temperature variation. The present article explained the nature of three different refrigerants R-134a, R-12 and R-22 on the basis of exergetic efficiency and total irreversibility as the performance parameters with evaporator temperature variation. REFPROP software used for calculation of different specified points of state and others thermophysical properties of the given refrigerants. Based on the exergy analysis, exergy loss decreases as the evaporator temperature rises and second law efficiency decreases along with the evaporator temperature rise. Exergy loss for R-134a is maximum and R-12 shows minimum and R-22 is in between but closed to R-12. The second law efficiency for R-12 is maximum, followed by R-22 and minimum for R-134a.

The drag coefficient of the nacelle lip-skin model was investigated to analyze the aerodynamic performance of the bias acoustic liner underneath the nacelle lip-skin at lowspeed free stream velocities. Drag coefficient reduction, using the bias flow of a bias acoustic liner on a nacelle lip-skin, is discussed for incompressible flow condition. The experimental data were recorded to analyze the nacelle lip-skin’s drag coefficients. The investigation covered four different bias flow areas to total nacelle lip-skin area ratios, ranging from 0 % to 12 %, at Reynolds numbers ranging from 2.2×105 to 3.5×105 and the nacelle internal static pressure of 0- 90 Pa, with the uncertainty of the experimental data being less than 10 %. The results show that the drag coefficient is reduced by up to 19 % as the ratio of the bias flow area to the total nacelle lip-skin area increases from 0 % to 12 %. In the transition flow regime, the drag coefficient increases gradually with Reynolds number. In addition, the optimum nacelle internal static pressure of present study was found to be 60 Pa.

Air transport is very frequent to assure worldwide social connection and commercial purposes. The use of aviation fuel demand on huge amounts becomes tensed due to the depletion of fossil fuel. Furthermore, the greenhouse emission offering vigorously by fossil fuel reduces the environment quality and human life. Therefore, it is clearly coming on priority to get attention towards alternative aviation fuel from renewable sources. However alternative fuel must be compatible with the conventional fuel in terms of its physical properties such as viscosity, energy density, sustainability, affordability and availability. The comparison to replacement of conventional fuel by alternative fuel motivates to study the properties. Measurements of Atomization spray characteristics of aviation fuels followed by comprehensive properties for a clear figure. This study is about to study the procedure to examine fuel and blends properties by developing spray atomization.

Errors in the accident data arise due to several individual and institutional shortcomings with inaccurate or ambiguous locations being the most serious amongst them. To overcome this issue a procedure has been devised in this study to rectify accident locations in the Malaysian accident data. The algorithm uses filtered search technique to match the accidents from the accident database with intersections from the field database. A total of 2809 accident records were screened for this purpose and 304 intersections were surveyed. The results showed that the algorithm is able to match up to 60% of the accidents to their respective locations depending upon the quality of the available records. Information related to only five parameters; major road width, landuse, lane marking, traffic control and geometry, are required for its implementation. Unlike geographic coordinates, these parameters are easily measurable and do not require any specialized equipment. The procedure is more relevant to low- and middle-income countries, where landmarks are much commonly used for location identification instead of geographic coordinates.

Increasing the count of transistors packed within integrated circuits necessitates efficient communication architecture such as Network-on-Chip (NoCs) to deal with scalability, bandwidth, latency, and optimized CPU core utilization goals. To extend the applicability of Moore’s law, multiprocessor architectures have been introduced, which in turn requires a higher level of synchronization and concurrency to enable enhancement in system performance. This research deals with global communication for NoC-multi-core system using the Intelligent Adaptive Arbitration technique to enable task parallelization by showing a perspective for the deployment of Intelligent Adaptive Arbitration on different NoC architecture(s) to enable parallel computing with fair bandwidth distribution and low latency. This research also opens up room for the various network-on-chip topology to constitute a unification of the latest trends of intra-chip communication.

Aviation industry is one of the main contributors and fastest-growing sectors in the world economy. Fuel consumption from this industry is one of the major issues that have drawn the attention of both professionals and researchers in recent years. The high dependency along with the high consumption of aviation fuel on petroleum plays a crucial role in environmental degradation due to increased carbon dioxide and other emissions, as well as in the increasing rate of fossil fuel depletion. Therefore, various potential technologies have been developed and further investigated to produce alternative aviation fuels, especially biofuels. In this article, principles, sustainability, and main concerns of different alternative aviation fuel processing technologies, with some focus on biofuels, are discussed in challenges and possible remedies. The major ecological problems connected with the application of conventional jet fuels in contrast to The advantages of biofuels implementation in the aviation industry are also highlighted. This work is aimed to show the state of the art of current alternative aviation fuels, their production technologies, and the potentiality of replacing the conventional jet fuel.

Air transport is already a well-known transportation in assuring the need of worldwide social connection and commercial purposes. Nowadays huge demand on aviation fuel increases severe tense due to depletion of fossil fuel. Furthermore, the increases of greenhouse gas emission from the fossil fuel reduces the environment quality and human life. Hence, an attention towards alternative aviation fuel from renewable sources has become a priority as it could offer greener aviation. However alternative fuel must be compatible in comparison of the conventional fuel in terms of its physical properties such as viscosity, energy density, sustainability, affordability and availability. Those properties will affect spray characteristics and leads to combustion quality. Therefore, this study presents a review on the different alternative fuels and their compatibility in the aircraft engine. The importance of spray characteristic on the engine and different experimental approach to examine the spray characteristics of fuel particularly the penetration length, spray morphology, cone angle and atomization of the fuel also are presented. This work is beneficial in providing understanding on alternative fuels and spray atomization examination.

Propellant grain burnback analysis is crucial for solid rocket motor design and performance prediction. Unlike 2D grain configurations, 3D configurations are complex, hence, simulating their burnback inside the rocket combustion chamber is a tedious and time-consuming process. This study proposes a fast and simple approach for modeling, and evaluating the burning area of 3D propellant grains, based on particular features available in a commercial CAD software. A common 3D Finocyl grain configuration available in the literature has been taken as a test case. The results obtained from the proposed approach were compared with the published experimental data and showed good agreement. The proposed approach can handle any arbitrary complex grain geometry and provide fast and reliable analysis for the preliminary design stage of solid propellant rocket motors.

One of the popular ways to improve thermal efficiency of porous media burners is by enabling smart materials in reaction zone. In this experimental work, a predefined bilayer porous media micro burner was made to achieve both surface and submerged flame for a foam type (Alumina) of reaction layer and compared with conventional style of using discrete type. Moreover, preheat layer was also made up of foam (porcelain), which helped in attaining stable flame. This work mainly aimed to show burner behavior from rich to lean region at critical equivalence ratios. During surface mode combustion highest temperature was recorded for foam type was at equivalence ratio of 1.1, while discrete type was 1.3. Similarly, submerged mode combustion reordered maximum temperature for both foam and discrete type was around 0.6. Finally, thermal efficiencies where calculated at suitable equivalence ratios and emitted emission from the burner tip was also taken into considerations.

This research paper presents a computational and analytical investigation of aerodynamic derivatives in an oscillating wedge. Unsteady hypersonic similitude has been apprehended for an oscillating wedge with an attached bow shock at a large incidence angle. The problems of instability and shock waves are generally associated with hypersonic flow and, therefore, it is imperative to evaluate aerodynamic models that can solve these problems. Lighthill’s piston theory is an unsteady aerodynamic model that is valid for an oscillating wedge with an attached shock wave. The analytical solution verifies that both the stiffness and the damping derivatives attain high values when the semi-vertex angle of the wedge is increased, while both derivatives assume lower values at increasing Mach numbers. Similarly, the pressure distribution over the wedge is evaluated to determine the details of how the developing flow cause the instabilities. Our study presents the contour plots of pressure, temperature, density, and Mach number that unravels the positions of flow separations in an oscillating wedge model.

This paper presents an experimental study of airflow from convergent-divergentnozzles discharged into enlarged duct, focusing attention on the flow development in the duct. To investigate the influence of active control on the flow field developed in the duct, the tiny jets of 0.05 mmradiuslocated at 900interval along the base at 6.5 mm from the main jet were employed. The Mach number tested in the present study was 1.48. The area ratio tested was 2.56. The NPR tested are from 3, 5, 7, and 9 respectively. The L/D ratio of the duct was varied from 10 to 1. The level of expansion at the nozzle exit influences the wall pressure very strongly. When the micro jets were activated they found to influence the base region, taking the wall pressure to considerably higher values, for most of the cases. Flow field in the duct with and without control remains the same.

The applications of porous media burners are of often keen interest to researchers because of many modern advantages, such as high thermal efficiency, stable flame and low emission rate. In this current experimental work, a microburner was made built to achieve both surface and submerged flame for three different thicknesses of reaction layers. A reaction layer of discrete alumina with a predefined thickness of preheat layer was used for combustion. Reaction layer was accordingly replaced with different thicknesses of 10mm, 20mm and 30mm. This work mainly aimed to show burner behavior with increase in thickness of reaction layer thus suggesting the optimum equivalence ratio from best burner performance. Interesting and unique behavior of the burner was encountered for each thickness of the reaction layer. Highest surface temperature was found out with 10mm of reaction layer, while highest wall temperature was incorporated with 20mm of reaction layer. Equivalence ratio of 0.3 is best suitable for optimum p...

The paper demonstrates the drag coefficient on the nacelle lip skin with and without bias acoustic liner. It is acknowledged that bias acoustic liner potentially reduces the drag coefficient and enhances the fuel efficiency of the aircraft. In the present study,the geometric mesh modelling of nacelle lip-skin has been developed using GAMBIT pre-processor, and FLUENT 14.0 CFD code is employed to obtain the numerical results. According to the results, drag coefficient of nacelle lip reduces by 90.5% with bias acoustic liner as compared to drag coefficient of nacelle lip-skin without bias acoustic liner. Therefore, bias acoustic liner with bias flow has potential to reduce the drag coefficient apart from being utilized in hot air anti-icing.