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Turboexpansion is a concept which is aimed at reducing the fuel consumption of pressure-charged combustion engines by providing over-cooled air to the engine prior to its induction in the combustion chamber. The performance of the engine is dependent on intake charge density which is preferred to be high at reduced charge air temperature. This becomes achievable through a cooling system known as a turbo expander which expands a high-pressure gas to produce work that is usually employed to drive a compressor. Though, initially used for the purpose of refrigeration in industries, for the past few decades various researches have proved its efficiency in internal combustion engines. In gasoline engines, it is usually employed to extend the knock limit and reduce carbon emissions. Also, an extension to the knock limit allows several improvements in parameters such as increased specific output, an increase in compression ratio and a reduction in the fuel consumption of the engine.

Flow separation is one of the primary causes of increase in form drag in vehicles. This phenomenon is also visible in the case of lightweight vehicles moving at high speed, which greatly affects their aerodynamics. Spherical depressions maybe used to delay the flow separation and decrease drag in such vehicles. This study aims for optimization of aspect ratio (AR) of spherical depressions on hatchback cars. Spherical depressions were created on the bonnet of a generalized light vehicle Computer-Aided Design (CAD) model. The diameter of each spherical depression was set constant at 60 mm, and the center-to-center distance between consecutive spherical depressions is fixed at 90 mm. The AR of spherical depressions was taken as the parameter that was varied in each model. ARs 2, 4, 6, and 8 were considered for the current investigation. Three-dimensional (3D) CFD analyses were then performed on each of these models using a validated computational model.

Non-edible vegetable oils have a huge potential for biodiesel production and also known as second generation feedstock’s. Biodiesel can be obtained from edible, non-edible, waste cooking oil and from animal fats also. This paper focuses on production of biodiesel obtained from mixture of sesame (Sesamum indicum L.) oil and neem (Azadirachta indica) oil which are easily accessible in India and other parts of world. Neem oil has higher FFA content than sesame oil. Biodiesel production from neem oil requires pretreatment neutralization procedure before alkali catalyzed Trans esterification process also it takes large reaction time to achieve biodiesel of feasible yield. Neem oil which has very high FFA and sesame oil which has low FFA content are mixed and this mixture is Trans esterified with no pre-treatment process using molar ratio of 6:1.Fuel properties of methyl ester were close to diesel fuel and satisfied ASTM 6751 and EN 14214 standards.

Concerns about long term availability of petroleum based fuels and stringent environmental norms have been a subject for deliberations around the globe. The vegetable oil based fuels and alcohols are very promising alternative fuels for substitution of diesel, reduce exhaust emissions and to improve combustion in diesel engines which is mainly possible due to oxygenated nature of these fuels. Jatropha oil is important non-edible oil in India which is either used in neat or modified form as diesel fuel. Furthermore n-butanol is renewable higher alcohol having properties quite similar to diesel fuel. In the present study, n-butanol was blended in Jatropha Oil (JO) and Jatropha Oil Methyl Ester (JME) on volumetric basis (10 and 20%). The blends were homogeneous and stable and there was no phase separation. The different physicochemical properties of blends were evaluated as per relevant standards.

The present world scenario faces a serious threat from increasing dependence on fossil fuels. This has triggered the awareness to find alternative energy as their sustainable energy sources. Biodiesel as a cleaner renewable fuel may be considered as a good substitution for diesel fuel due to it being used in any compression ignition engine without any modification. The main advantages of using biodiesel are its renewability and better quality of exhaust gas emissions. In terms of emissions from biodiesel, the cause of concern continues to be the NOx emissions. Therefore, to compliment the functioning of biodiesels, Urea-SCR over Cu-ZSM5 catalyst is an effective option due to its ability to convert NOx into nitrogen and water. There has been increasing concerns that biodiesel feedstock may compete with food supply in the long term. The recent paper focuses on use of two non-edible oils mahua oil and fish oil (processed from waste produced by fish).

Wind energy is clean and renewable source of energy that is an attractive alternative to non-conventional sources of energy. Due to rapid increase in global energy requirements, this form of energy is gaining its share of importance. Unlike nuclear power or tar sand oils, wind energy does not leave a long-term toxic legacy. Using MATLAB algorithms, multi-optimization of wind turbine design can be achieved. Therefore, an aerodynamic mathematical model is developed to obtain the optimal chord length and twist angle distribution along the blade span. Further, a promising generic blade design is used to initialize a detailed structure optimization wherein leading edge panel (LEP), Spar cap, Shear web, Trailing edge panel (TEP) reinforcement are sized using composite laminates so that the blade is according to the intended design standard. Initially blade airfoils are analyzed on 2D platform and then the results are used to construct 3D model of Horizontal Axis Wind Turbine (HAWT) blade.

Recent scenario of fossil fuel depletion as well as rising emission levels has witnessed an ever aggravating trend for decades. The solution to the problems has been addressed by investments and research in the field of fuels; such as the use of cleaner fuels involving biodiesel, alcohol blends, hydrogen and electric drivelines, as well as improvement in traditional technologies such as variable geometry systems, VVT load control strategies etc. The developments have highlighted the enormous potential present in such systems in terms of maximizing engine efficiency and emission reductions. The present paper aims at designing and implementing an intake runner system for a CI engine capable of providing flexibility with variations in operating conditions. Primarily, the design aims at altering the air flow phenomenon within the primary intake of the engine by inducing swirl in the runner through a secondary runner.

The power generation, agriculture, and transportation sectors are dominated by diesel engines due to better thermal efficiency and durability. Diesel engines are also a major contributor to the air pollutants such as NOx and particulate matter. Acetone-butanol-ethanol (ABE) is considered a promising alternative fuel as it emits less pollutants compared to conventional fuels. In current work, the ABE used was of the ratio (3:6:1) and four samples were prepared for engine trial ABE (10%90%diesel), ABE (20%80%diesel), ABE (30%70%diesel) and ABE (40%60%diesel). Their physio-chemical properties like kinematic viscosity, density, specific gravity and calorific value were checked and tested on compression ignition engine at different operating parameters. The experimental work was conducted upon Kirloskar 4-stroke single cylinder, vertical, air-cooled 661cc compression ignition engine at different speeds and loads.

Internal combustion engines are the backbone of contemporary global transportation. But the major drawbacks associated with them, are the exhaust gases. These include carbon monoxide (CO), unburned hydrocarbons (UBHC), oxides of nitrogen (NOx), odor, particulate matter (PM) etc. Among them the emissions of oxides of nitrogen (NOx) and the particulate matter are the reasons of serious concern. For NOx reduction in recent developing technologies, diesel water emulsion was found the best approach for the existing engines by researchers. In the present study, performance and emission statistics of a diesel engine using diesel water emulsion operating at different compression ratios from 17:1 to 18:1 was performed. Stable Emulsions were prepared with 5%, 10%, 15%, 20% and 25 % (v/v) water concentration with variable agitation speed ranging from 5000-15000 rpm along with two surfactants. Various physico-chemical properties of emulsions were tested for all six samples including diesel.

The world today is majorly dependent upon fossil fuels for power generation, of which diesel forms an integral part. Diesel engines, having the highest thermal efficiency of any regular internal or external combustion engine, are widely used in almost all walks of life and cannot be dispensed with in the near future. However, the limited availability of diesel and the adverse effects of diesel engine emissions like nitrogen oxide (NOx) and soot particles raise serious concerns. Hence, their performance and emission improvement continues to be an avenue of great research activity. In this research work, the effects of blending Diethyl Ether with diesel in various proportions (5%, 10%, 15% and 20% by volume) were evaluated on engine performance and emissions of an industrial internal combustion engine.

Biodiesel is a potential substitute for diesel and extensive research is carried in India on production and utilization of biodiesel from a variety of edible/non-edible, animal fat and waste oils. However, issues like stability, clogging, increased NOx, and high consumption rate etc. are some of the critical issues which are associated with long-term use of these alternative fuels in a diesel engine. The recent developments in science and technology may have concreted a method to create nano measure vigorous resources that have incredible benefits to micron sized constituents. Nano liquids may be a fresh period of compact-fluid complex constituents comprising of nano sized concrete elements disseminated into a base liquid. The present study investigates the effect of doping metal oxides nanoparticles with waste fish oil-based biodiesel. For the present study, the blends of fuel are prepared by using 30ppm each of titanium dioxide and alumina nanoparticles respectively.

The energy crisis coupled with depleting fuel reserves and rising emission levels has encouraged research in the fields of performance enhancement, emission reduction technologies and engineering designs. The present paper aims primarily to offset the problem of high emissions and low efficiencies in low cost CI engines used as temporary power solutions on a large scale. The investigation relates to the low cost optimization of an intake runner having the ability to vary the swirl ratio within the runner. Test runs reveal that NOx and CO2 follow a relatively smaller gradient of rise and fall in their values depending on the configuration; whereas UHC and CO have a rapid changes in values with larger gradients. However, in a relative analysis, no configuration was able to simultaneously reduce all emission parameters and thus, there exists a necessity to find an optimized configuration as a negotiation between the improved and deteriorated parameters.

Worldwide, research is going on numerous types of engines that practice green and alternative energy such as natural gas engines, hydrogen engines, and electric engines. One of the possible alternatives is the air powered car. Air is abundantly available and can be effortlessly compressed to higher pressure at a very low cost. After the successful development of Compressed Air Engines, engineers shifted their focus in making this technology cost effective and feasible. This led to advancement in the field of pneumatics that is advanced Compressed Air Engine Kit (used for conversion of a small-two stroke SI engine to Compressed Air Engine) where its frugality and compatibility is kept at high priority. This research is in continuation with our previous project of development of an advanced Compressed Air Engine kit and optimisation of injection angle and injector nozzle area for maximum performance.

Increased demand and use of fossil fuels in transportation sector accompanied by the global oil crisis does not support sustainable development for the future generations to come. Not only that, today's on-road vehicles produce over one third of the CO and NOX present in our atmosphere and over twenty per cent of the global warming pollution. This air pollution carries significant risks for human health and the environment. Through clean vehicle and fuel technologies, it is possible to significantly reduce air pollution from our vehicles. In such a grim situation, Compressed Air Vehicles (CAV) powered by pressurized air stored in high pressure storage tanks seem to be one of the practical solutions available for tackling the fuel crisis and environment related issues.

The behavior of flow over an automobile’s body has a large effect on vehicle performance, and automobile manufacturers pay close attention to the minimal of the details that affect the performance of the vehicle. An imbalance of downforce between the front and rear portion of the vehicle can lead to significant performance hindrances. Worldwide efforts have been made by leading automobile manufacturers to achieve maximum balanced downforce using aerodynamic elements of vehicle. One such element is the front splitter. This study aims to analyze the aerodynamic performance of automobile at various splitter overhang lengths using Computational Fluid Dynamics (CFD). For the purpose of analysis, a three-dimensional (3D) CFD study was undertaken in ANSYS Fluent using the realizable k-ε turbulence model, based on the 3D compressible Reynolds-Averaged Navier-Stokes (RANS) equations.

Globally, transportation is the second largest energy consuming sector after the industrial sector and is completely dependent on petroleum products and alternative technologies. So, fossil fuel consumption for energy requirement is a primary concern and can be addressed with the fuel consumption reduction technologies. Transportation sector is mainly using diesel engines because of production of high thermal efficiency and higher torque at lower RPM. Therefore, diesel consumption should be targeted for future energy security and this can be primarily controlled by the petroleum fuel substitution techniques for existing diesel engines. Some of the fuel, which includes biodiesel, alcohol-diesel emulsions and diesel water emulsions etc. Among which the diesel water emulsion (DWE) is found to be most suitable fuel due to reduction in particulate matter and NOx emission, besides that it also improves the brake thermal efficiency.

The increment in the application of fossil fuels is leading the world into a catastrophic state both environmentally and economically. Current demand for fuels exceeds its imminent supply and rather sooner than later energy demands will have to shift towards non-conventional fuels to cope with the situation. With constant developments in the automotive sector, several solutions have been found but none have been as good as gasoline to substitute it in the commercial market. One such solution being compressed air might solve this global fuel crisis, which serves a glowing advantage of being cheaper and greener as it produces zero tail-pipe emissions, and can help in decreasing automobile’s contribution to global warming. Though the potential energy stored in the compressed air limits its application to light duty vehicles and still there will be a need for other alternative solutions for the heavy duty vehicles in order to relieve the pressure from the fossil fuels.

The diesel engine has for many decades now assumed a leading role in both the medium and medium-large transport sector due to their high efficiency and ability to produce high torque at low RPM. Furthermore, energy diversification and petroleum independence are also required by each country. In response to this, biodiesel is being considered as a promising solution due to its high calorific value and lubricity conventional petroleum diesel. However, commercial use of biodiesel has been limited because of some drawbacks including corrosivity, instability of fuel properties, higher viscosity, etc. Biodiesel are known for lower CO, HC and PM emissions. But, on the flip side they produce higher NOx emissions. The addition of alcohol to biodiesel diesel blend can help in reducing high NOx produced by the biodiesel while improving some physical fuel properties.

Ever increasing consumption of fossil fuel and large scale deterioration of environment are mandating employment of renewable fuels. Researchers all over the world are experimenting on variety of alternative fuels for meeting future energy demands. Biodiesel is one of the most promising alternative fuels due to lower CO, HC and PM emissions. However, NOx emissions are increased in case of biodiesel in CI engine. The present study focuses on evaluation of performance and emission characteristics of a medium capacity diesel engine on blends of fish oil biodiesel and diesel blends employing EGR. Fish oil was transesterified with methyl alcohol to produce methyl ester. B20 blend of biodiesel was used since it balances the property differences with conventional diesel, e.g., performance, emission benefits and cost. Further, B20 blend can be used in automotive engines with no major modification. NOx formation takes place when combustion temperature is more than 2000K.

Internal combustion engines are extensively used in every field of life in today's world. Diesel engines being more efficient are preferred in the industrial and transportation sector in comparison to spark ignition engines for their higher efficiency, versatility and ruggedness. The major emissions of diesel engines are oxides of nitrogen (NOx), particulate matter (PM), carbon dioxide (CO2), carbon monoxide (CO). Among these emissions, oxides of nitrogen (NOx) and the particulate matter are the reasons of serious concern. For reduction of oxides of nitrogen (NOx) and particulate matter simultaneously, the use of Homogeneous Charge Compression Ignition (HCCI) have provided a sustainable solution in the present scenario. Further, the use of CNG in HCCI engine along with pilot diesel injection; the emissions have been decreased drastically. Homogeneous mixing of fuel and air leads to cleaner combustion and lower emissions.