Search Results

The continued reliance on fossil fuel energy resources is not sufficient to cater to the current energy demands. The excessive and continuous use of crude oil is now recognized as unviable due to its depleting supplies and elevating environmental degradation by increased emissions from automobile exhaust. There is an urgent need for a renewable and cleaner source of energy to meet the stringent emission norms. Hythane is a mixture of 20% hydrogen and 80% methane. It has benefits of low capital and operating costs and is a cleaner alternative than crude oil. It significantly reduces tailpipe emissions and is the cheapest way to meet new emission standards that is BS-IV. Hythane produces low carbon monoxide (CO), carbon dioxide (CO2) and hydrocarbons (HC) on combustion than crude oil and helps in reduction of greenhouse gases.

Heat exchangers are widely used in various transportation, industrial, or domestic applications such as thermal power plants, means of heating, transporting and air conditioning systems, electronic equipment and space vehicles. In all these applications improvements in the efficiency of the heat exchangers can lead to substantial cost, space and material savings. Hence considerable research work has been done in the past to seek effective ways to improve the efficiency of heat exchangers. In this paper the effect of natural convection is justified between exterior solid wall surfaces and the surrounding air inside the enclosure. Designing of electronic devices, heavy industrial equipments such as boilers, turbines etc. and building aerodynamics are some of the real world application associated with this study.

Diesel Engines are widely used in transportation, industrial and agriculture sectors worldwide due to their versatility and ruggedness. However, they also emit harmful emissions detrimental to human health and environment. Apart from environmental degradation, the perturbation in international crude oil prices is also mandating use of renewable fuels. In this context, vegetable oils such as Jatropha Curcas due to their carbon neutral nature and widespread availability, seems to present a promising alternative to the mineral diesel. Straight vegetable oils (SVO) are not recommended for direct diesel engine application due to their higher viscosity, poor volatility etc. and dilution of straight vegetable oil may effectively enable its direct application in unmodified diesel engines. In the present study, Jatropha oil was diluted with n-Butanol to improve the fuel properties of the blend.

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.

The increasing rate of fossil fuel depletion and large scale debasement of the environment has been a serious concern across the globe. This twin problem of energy crises has caused researchers to look for a variety of solutions in the field of internal combustion engines. In this current scenario the issue of fuel availability has increased the use alternative fuels, especially alcohol derived fuels. Alcohol-diesel blends can be been seen as a prominent fuel for CI engine in the near future. Previous research on the use of alcohol as an alternative fuel in CI engines is restricted to short branch alcohols, such as methanol and ethanol. Despite their comparable combustion properties longer chain alcohols, such as butanol, isobutanol and pentanol have been barely investigated. In the present study performance and emission characteristics of an isobutanol-diesel blend was studied. One of the major problems encountered by isobutanol in CI engines is its low cetane rating.

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.

The crankshaft translates the reciprocatory motion of the piston into rotary motion. A flywheel is generally connected to the crankshaft to reduce the vibrating characteristic of four stroke cycle. Counterweights are added for each reciprocating piston to provide engine balance while operating. Gasoline engines have curtailed compression ratio therefore shorter stoke length as a deduction have higher RPM in comparison to diesel counterpart. A crankshaft is subjected to enormous stresses, potentially equivalent of several tones of force. Failure of the crankshaft is predominantly due to violent vibrations, insufficient lubrication, excessively pressurized cylinder. This research aims to examine the stress subjected to acute points on a crankshaft. Three dimension model of 4 stroke single cylinder engine crankshaft is modeled using SolidWorks v18. End conditions were applied taking into consideration the engine mountings of the crankshaft.

The art and science of thrust vectoring technology has seen a gradual shift towards fluidic thrust vectoring techniques owing to the potential they have to greatly influence the aircraft propulsion systems. The prime motive of developing a fluidic thrust vectoring system has been to reduce the weight of the mechanical thrust vectoring system and to further simplify the configuration. Aircrafts using vectored thrust rely to a lesser extent on aerodynamic control surfaces such as ailerons or elevator to perform various maneuvers and turns than conventional-engine aircrafts and thus have a greater advantage in combat situations. Fluidic thrust vectoring systems manipulate the primary exhaust flow with a secondary air stream which is typically bled from the engine compressor or fan. This causes the compressor operating curve to shift from the optimum condition, allowing the optimization of engine performance. These systems make both pitch and yaw vectoring possible.

The Aerofoil theory along with its design has integrated itself into the vast areas of applications ranging from Automobile, Aeronautical, Wind Turbine, Micro-Vehicles, UAVs applications. In this paper, knowing the intricacy of the airfoil's applications, A MATLAB Code for NACA-2415 Airfoil is developed and a Model with dimensions c=180mm, w=126mm, tmax=27mm is generated. The model is then subjected to Flow Simulation with various input parameters: Reynolds Numbers taken are- (REN-1) 105 and (REN-2) 2×105 [Laminar External Flow], Angles of attack taken are-0°, 4°, 8°, 12°. The pressure and velocity distribution along the airfoil sketch curve are graphed qualitatively, emphasizing on the flow separation leading to the transition from laminar to turbulent flow. The various aerodynamics characteristic curves for coefficient of pressure, coefficient of lift and coefficient of drag are plotted against different angle of attacks for REN-1 and REN-2.

The growing energy demand and limited petroleum resources in the world have guided researchers towards the use of clean alternative fuels like alcohols for their better tendency to decrease the engine emissions. To comply with the future stringent emission standards, innovative diesel engine technology, exhaust gas after-treatment, and clean alternative fuels are required. The use of alcohols as a blending agent in diesel fuel is rising, because of its benefits like enrichment of oxygen, premixed low temperature combustion (LTC) and enhancement of the diffusive combustion phase. Several researchers have investigated the relationship between LTC operational range and cetane number. In a light-duty diesel engine working at high loads, a low-cetane fuel allowed a homogeneous lean mixture with improved NOx and smoke emissions joint to a good thermal efficiency.

Increased dependency on fossil fuels has led to its depletion as well as affected the environment adversely. Moreover, increasing crude oil prices is pressurizing vehicle manufacturers to invent new technology so as to increase fuel economy and at the same time to keep emissions under control. Hydrogen has gained popularity not just in terms of being an abundant alternative but also due to being a very clean propellant. In the present investigation, hydrogen boosting has been performed on an SI engine running on gasoline-methanol and ethanol-gasoline blends to determine the additional advantages of the same compared to pure gasoline operation. The engine selected for experimental analysis is a single cylinder, air cooled spark ignition engine that has been modified for hydrogen injection in the intake manifold prior to the port with the injection timing being held constant throughout the experiment.

Primary energy sources can be divided into non-renewable and renewable. The over-exploration of non-renewable sources for energy availability imposes considerable impacts on the environment. Reducing the use of fossil fuels would significantly reduce the carbon dioxide emissions and other pollutants produced. The future drift for sustainable production of renewable energy is cautiously thoughtful for it has been increasingly understood that first generation biofuels, majorly produced from food crops that are limited in their ability to achieve targets for biofuel production, climate change mitigation and economic growth. These concerns have increased the interest in developing second generation biofuels produced from non-edible feedstock such as microalgae, which potentially offers greatest opportunities in the longer term. Microalgae are considered a very promising feedstock for biodiesel production due to their very high yield and their no competition with food crops.

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).

The present consumption rates and heavy dependence on fossil fuels pose a humongous threat to the environment. The increased pollution in urban areas is already causing serious sociological, ecological and economic implications. The issue of energy security led governments and researchers to look for alternate means of renewable and environment friendly fuels. Biodiesel has been one of the promising, and economically viable alternatives. The biodiesels are reported to cause reduction in CO, HC and PM emissions. However, NOx emissions are increased in case of biodiesel in CI engine. Therefore, a Urea-SCR over Fe-ZSM5 honeycomb substrate (400cpsi) zeolite catalyst after treatment system is an effective technology to reduce emissions for biodiesel applications. Exhaust gases pass through the catalyst and reactions take place along its surface, consequently converting NOx into nitrogen and H2O.

The danger posed by climate change and the striving for securities of energy supply are issues high on the political agenda these days. Governments are putting strategic plans in motion to decrease primary energy use, take carbon out of fuels and facilitate modal shifts. Man's energy requirements are touching astronomical heights. The natural resources of the Earth can no longer cope with it as their rate of consumption far outruns their rate of regeneration. The automotive sector is without a doubt a chief contributor to this mayhem as fossil fuel resources are fast depleting. The harmful emissions from vehicles using these fuels are destroying our forests and contaminating our water bodies and even the air that we breathe. The need of the hour is to look not only for new alternative energy resources but also clean energy resources. Hydrogen is expected to be one of the most important fuels in the near future to meet the stringent emission norms.

Bhutan is a small nation in the eastern Himalayas, between two of the world's largest neighbors and fastest-growing economies; China, and India. The GDP of the country is $2.707 Billion as of 2022. Bhutan’s largest renewable source is hydropower, which has a known potential of 30,000 MW. However, it has only been able to harvest only 1,480 MW (5% of the potential). The current overall electrification rate is 99% overall with 98.4% in rural areas. It exports 75.5% of total electricity generated in the country to India. However, the reliable supply of electricity remains a big challenge. The government is also pushing the use of renewable energy sources like solar and wind to diversify the energy mix and enhance the power security of the country. The share of renewable energy is very minimal at present amounting to 723 kW Solar PV and 600 kW Wind power.