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Vegetable oils are characterised as diesel engine fuel due to their properties of adiabatic combustion under high pressure and temperature. The semi-adiabatic type of engines can be effectively utilized for achieving the best performance from combustion of vegetable oils. The present study reports the performance and exhaust emissions of such type of engine by using diesel fuel - linseed oil blends and esterified linseed oil and the results as obtained are compared with that of 100% diesel fuel operation. The influence of coating thickness and compression ratio have also been reported. Results show that BSFC, exhaust gas temperature, CO level and smoke density are increased but Br. Th. Effic. and NOx level are decreased both in diesel fuel - linseed oil blends and esterified linseed oil compared to 100% diesel fuel operation. Results with esterified linseed oil are comparatively better than diesel fuel - linseed oil blends with higher degree of insulation.

Vegetable oil as a biomass-based energy, can be considered as possible alternative fuel. Neat Vegetable oil is too viscous, has poor volatility, comparatively low cetane number and having different chemical structures than diesel fuel. In DI diesel engine, these fuels can not be used without further processing. Modified or vegetable oils processed by esterification can mitigate these problems and become more suitable for diesel engine application. The present experimental study reports the performance and exhaust emissions of a DI diesel engine by using methyl esters karanji oil and heated karanji oil in comparison to 100% diesel operation. The influence of injection pressures and injection timings have also been reported. The data brake specific fuel consumption and brake thermal efficiency generated using esterified karanji oil and diesel are comparable. The maximum variation of the emission CO for esterified karanji oil is about 35% higher than that of diesel.

A simple and cost effective vitreous enamelling technique is being adopted in the application of thermal barrier coating for internal combustion (IC) engine components. The raw materials including the process of coating are less costly in comparison to plasma spray technique. The coating using yttria partially stabilized zirconia with this technique is found effective for insulation of the engine components. The results obtained from this process are comparable with the published results using plasma spray [1]*. At the speed of 1500 rpm, brake specific fuel consumption (BSFC) decreases upto 9.99% with 200 micron (μ) glass ceramic coating piston whereas with 500 μ coating, it decreases upto 19.67% with advanced injection angle (40° before top dead centre) resulting higher thermal efficiency compared to base line engine.

The experimental investigation was conducted on a CI version Ricardo variable compression single cylinder naturally aspirated engine to examine the effects of ceramic coating on performance and exhaust emissions. Tests were carried out at 1500rpm over a wide range of part loads, varying injection timings and compression ratios (CR). The top of the piston was insulated by using Yttria-partially stabilized zirconia with a bond coat alumino boro silicate. The technology by which the piston head was insulated is much more economical and simpler than the plasma-spray process usually used for coating with ceramics. Results show that at 30% of the rated load, BSFC decreases upto 9.99% at 40° injection bTDC (before top dead centre) for CR-19 resulting higher thermal efficiency than base line engine. Ignition delay is longer in ceramic coated engine than its counter part. For CR-18 and 19 these ranges are 1.3% to 7.94% at different injection timings.