重力金属型铸造在充型模拟时出现的问题!

附件内是活塞的STL文件,属于金属模重力铸造,我在用flow3d模拟充型时(采用压力边界:在对话框中输入7350(CGS),大气压各处相同抵消掉不计算在内),在求解过程中出现以下的提示:
ressure iteration did not converge in itmax= 100 iterations
at t= 8.6578E+00 cycle= 21984 block= 1 epsi= 9.9876E+00 resid= 4.1277E+03 delt= 2.8215E-08
restarting cycle with smaller time-step size
============= mentor tip ===============
pressure iterations limiting time step.
1. check for poor mesh aspect ratios.
2. use ADI or GMRES solver.
3. try autot=2.0.
4. increase convergence tolerance epsi.
5. if nmat=1, try some compressibility
by setting rcsql > 0.
6. reduce alphamb for multi-block cases.
========================================
望版主能给解答一下是什么原因?小弟跪谢了!
附件 km138.part1.rar (512 KB) 2009-4-21 10:05, 下载次数: 1
km138.part2.rar (12.43 KB) 2009-4-21 10:05, 下载次数: 1