Thermodynamic simulation of porous-medium combustion chamber under diesel engine-like conditions

Abstract

Currently, one of the most important issue of the diesel engines is the non-homogeneity of the in-cylinder fuel-air mixture. Non-homogeneous mixture causes the non-uniform heat release and high-temperature gradient in the combustion chamber that followed by the production of unburnt hydrocarbons, carbon monoxide, nitrogen oxides and soot. Homogenous combustion decreases the production of the emissions. One novel method for achieving homogenous combustion is the use of porous medium (PM) within the combustion chamber of engine so as to separate the mixture formation process from combustion process. The present article thermodynamically investigates the effect of utilizing PM in a constant-volume combustion chamber via solving the energy equations for both the solid and fluid phases considering the chemical reaction of the fuel combustion. At first, numerical result is validated according to the experimental result of diesel fuel injection in a constant-volume combustion chamber with PM. Then, effects of the initial mixture and PM temperature, the porosity of the PM, the mean pores diameter as well as the use of fuels such as decane, isooctane, methanol, ethanol, propane and hydrogen on combustion initiation, and also pressure and temperature of the combustion chamber studied.