Numerical simulation and prediction of the performance of a direct injection turbocharged diesel engine

Abstract

Increases in fuel prices are constraining car manufacturers to produce highly efficient engines, noting greater regulation in terms of pollutant emissions. The greater complexity of modern engines has rendered the prototyping phase long and expensive. This is where engine modeling has in recent years become extremely useful and an indispensable tool when developing new engine concepts. This study deals with the numerical simulation and performance prediction for a turbocharged diesel engine with direct injection. To predict engine performance we developed a computer program for simulating the operation of a turbocharged diesel engine, and used the commercial software GT-Power to validate the simulation results. We then carried out a comparative study of indicated mean effective pressure, mean effective pressure, power, torque and brake specific fuel consumption obtained by an analytical model for thermodynamic cycle simulation of a turbocharged diesel engine using a computer program developed in Fortran and GT-Power. The Fortran program that was developed is currently used for modeling and the simulation of engine performance.

The influence of different parameters on the performance of the compression ignition engine

“…In general, increasing the compression ratio improved the engine performances (Menacer and Bouchetara 2013). Figure 5 shows the influence of the compression ratio (C r = 16:1 and 19:1) on the maximum brake power and maximum effective efficiency at full load, advance injection of 15°bTDC (before top dead centre) for GT-Power and the elaborate software.…”

“…The crank speed is uniform (steady-state engine). The rate of change of the volume with respect to time is given as follows (Gunter et al 2006;Menacer and Bouchetara 2013):…”

“…The computer program work out in discrete crank angle incremental steps from the outset the compression, combustion and expansion stroke. For the closed cycle period, Watson, Pilley, and Marzouk (1980) recommended the following engine calculation crank angle steps: 10°CA before ignition, 1°CA at fuel injection timing, 2°CA between ignition and combustion end, and finally 10°CA for expansion (Menacer and Bouchetara 2013). The solution is carried out with end results of each process taken as the starting conditions for the following process and end values of the completed thermal cycle taken as the starting values for the subsequent cycle.…”

“…and GT-Power software systems. This parameter has a substantial influence on the maximum power and smaller influence on maximum efficiency (Menacer and Bouchetara 2013). Figure 12(a) and 12(b) presents the influence of the injection timing and its impact on the thermodynamic cycle of the pressure and temperature in the cylinder.…”

The convection heat transfer rate evaluation of a 6-cylinder in-line turbocharged direct-injection diesel engine

“…In diesel engines, radiation heat transfer is negligible because its effect is very small, due to low soot and low temperature combustion [7], [8]: therefore it is ignored [9]. By applying the assumption of steady heat transfer for the present study, the convective heat transfer can be calculated by multiplying the simultaneous heat transfer coefficient, the instantaneous heat exchange area and the temperature difference [10]:…”