Numerical simulation of direct injection engine with using porous media

Porous media (PM) has interesting advantages compared with free flame combustion due to the higher burning rates, the increased power range, the extension of the lean flammability limits, and the low emissionsof pollutants. Future internal combustion (IC) engines should have had minimum emissions level under possible lowest fuel consumption permitted in a wide range of speed, loads and having good transient response. These parameters strongly depend on mixture formation and combustion process which are difficult to be controlled in a conventional engine. This may be achieved by realization of homogeneous combustion process in engine. This paper deal with the simulation of direct injection IC engine equipped with a chemically inert PM, with cylindrical geometry to homogenize and stabilize the combustion of engine. A 3D numerical model for PM engine is presented in this study based on a modified version of the KIVA-3V code.Due to lack of any published data about PM engine, numerical combustion wave propagation in a porous medium are compared with experimental data of methane-air mixture under filtration in packed bed and very good agreement is seen. Methane as a fuel is injected directly inside hot PM that is assumed, mounted in cylinder head. Lean mixture is formed and volumetric combustion occurs in PM. Mixture formation,pressure and temperature distribution in both phases of PM and in-cylinder fluid with the production of pollutants CO and NO and also effect of injection time, in the closed part of the cycle are studied.