PDF Model in compressible flows with shock waves

Hanxsi

hi,everybody. lately i am using fluent 6.2 to simulate a steady compressible turbulent reacting flow with shock waves.for some resons i have to use the PDF component model,but i found that it is impossible to get a convergent result,also i found that in the neighborhood of the shock waves the temperature field calculated by the PDF model is false because it is curiously high. i think there must be some error in the PDF model,may be in the energy equation as in the fluent 6.2 help 18.3.11 it is said that "Compressible Composition PDF Transport Simulations Compressibility is included when ideal-gas is selected as the density method in the Materials panel. For such flows, particle internal energy is increased by p*dv over the time step dt,where p is the cell pressure and dv is the change in the particle specific volume over the time step. " please help me. thanks you!