Numerical Study on Turbulent Two-Phase Flow in a Porous Media Combustion Chamber

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 field 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 Brinkman-Forchheimer-extended Darcy's equation is introduced into the numerical solver. A version of two-equation k - ε turbulence model suggested by Antohe and Lage is employed for the turbulence prediction in the PM. 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 structures. 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.