Performance Simulation of Direct-Injection Diesel Engine Operated with Neat Di-Methyl Ether 2008-01-2425

In modern research, computer simulation has become a powerful tool for IC engine performance prediction as it saves time and is also economical. A proposed theory or an innovation can be analyzed quickly using a computer and the setting up cost for an experimental work can be postponed until optimization is achieved. For the purpose of evaluating performance of direct injection diesel engine operated with neat oxygenated fuel, the literature data were found confined to experimental investigations and insufficient to serve the purpose because of the large number of oxygenated fuels available for testing.

Any improvement predicted in the combustion of the engine fuel will enhance the performance and reduce the emission simultaneously. Therefore oxygenated fuel combustion predictive capability is a acquit necessity at this point of time to screen the oxygenated fuels for better performance. The process of screening can be very well carried out by a computer simulation rather than by experiments considering the number, cost and time required. In this paper an initiative is taken towards the development of a universal model in ‘C’ language for this purpose with a novel approach.

The universal oxygenate correction factor formulated earlier for the performance simulation of DI diesel engine operated with oxygenate blended diesel has been used considering the heat input rather than fuel input so as to take care of the large variation in fuel heating values and it has also been shown that the universal oxygenate correction factor is equally hold good in the prediction of performance of DICI engine operated with neat oxygenated fuel also.

A typical DI diesel engine (bore × stroke: 92 × 96 mm, compression ratio: 17.7 & speed 960 rpm) operated with DME for which the SAE-published experimental investigation data were already available is taken for this simulation purpose. The pressure-time history synthesized with the help of universal load correction factor has been found agreed with the experimental investigation for the neat diesel operation. But for the neat DME operation, the pressure-time history synthesized with the help of universal oxygenate correction factor and universal load correction factor has been slightly deviated from the experimental investigation. However the peak pressure, brake power, brake thermal efficiency and brake specific energy consumption have been found in agreement with the experimental investigation for both neat diesel and neat DME operations of the engine.