摘要

To understand the working mechanism of the porous medium (PM) internal combustion engine, effects of a porous medium heat regenerator inserted into a combustion chamber on the turbulent flow characteristics and fuel-air mixture formation are studied by numerical simulation. The cylindrical chamber has a constant volume, in which a disk-shaped PM insert is fixed. A simplified model for the random structure of the PM is presented, in which the PM is represented by an assembly of a great number of randomly distributed solid units. To simulate flows in the PM a microscopic approach is employed, in which computations are performed on a pore-scale mesh and based on the standard k-E > turbulence model. A spray model, in which the effects of drop breakup, collision and coalescence are taken into account, is introduced to describe spray/wall interactions. Numerical computations are performed for the turbulent flows induced by a fuel spray outside and inside of the PM with different structure parameters. Calculation results show that the spray/PM interaction has substantial and positive influences on the fuel-air mixture formation and homogenization in the combustion chamber, which could be very advantageous in engine applications.