hi, everybody,i have some problems, i wish someone can help me^^ the problem is i similate a moving piston and moving displacer case. i use the "pressure based,unsteady",and ideal gas, and use the udf to control the piston and the displacer, but ,why the result pressure value increased, i use only 101325 pascal, but the value is from 80000 to 11000000 pascal, i looked out the density value , i found a strange situation, the density in the engine was increases, why?? even i gived it temperature, it is only 800k, the pressure shouldn't always increased. can someone help me?? if anyone want to see the case, you can give me your e-mail or msn or skype!! please>"<

Hei... email me your case files to herntan@gmail.com

i having a simulation of moving piston with direct injection. We might can help each other.