流固耦合，换了质量更好的网格流体突然就不收敛了？
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你好
PIMPLE: iteration 40 **time step continuity errors : sum local = 20238.39271, global = -1326.825454, cumulative = -1286.292262** **time step continuity errors : sum local = 1965.022984, global = -493.7266286, cumulative = -1780.018891** PIMPLE: iteration 22 GAMG: Solving for p, Initial residual = 0.1839153372, Final residual = 1.265686901e-06, No Iterations 20 GAMG: Solving for p, Initial residual = 0.1398796637, Final residual = 1.397575026e-06, No Iterations 17 GAMG: Solving for p, Initial residual = 0.1463017811, Final residual = 1.437462198e-06, No Iterations 16 GAMG: Solving for p, Initial residual = 0.121320625, Final residual = 6.97291136e-08, No Iterations 20 PIMPLE: iteration 23 .GAMG: Solving for p, Initial residual = 0.1600126604, Final residual = 1.256444652e-06, No Iterations 23 GAMG: Solving for p, Initial residual = 0.09022545056, Final residual = 7.317342264e-07, No Iterations 20 GAMG: Solving for p, Initial residual = 0.08084307981, Final residual = 7.297894683e-07, No Iterations 18 GAMG: Solving for p, Initial residual = 0.06296048891, Final residual = 7.500379861e-08, No Iterations 22你的问题在于：
1、瞬态项上，你的瞬态项很难收敛，残差爆掉了，这个似乎与你的瞬态项离散方式有关，可以试一下二阶向后差分。ddtSchemes { default CrankNicolson 0.9; }2、你的泊松方程收敛性很差，外循环很难收敛，残差很高，你定义的外循环收敛条件根本达不到，泊松方程在非正交修正后，迭代次数反而变多，证明你的网格质量可能较差。
建议：1.更换瞬态项离散方式。2.增加非正交修正次数，提高你的网格质量。
注意：外循环定义50次合理，一般难收敛问题，最多10次就可以收敛了。流固耦合交界面前几个时间步不收敛很正常，但是你这个是流体不收敛，这就不对了，建议你先单独跑一下流体看看，你这个流体设置不太好。
祝好~
