请教--关于模型unstable

zzteng

最近老被一个问题困扰。在做纯流体的模型时，经常碰到如下类型的warning, 虽然模型可以运行，但结果不对。
哪位有这方面的经验，谢谢指点.

*** WARNING *** CODE ADF2006:
    Model may be unstable! Ratio 1.3170E+14 of largest to smallest diagonal
    elements in factorized coefficient matrix is greater than 1.E+11. The
    largest diagonal element 9.95679E+10 corresponds to
    y-velocity at node (label) 9288 and the smallest
    diagonal element 7.55968E-04 corresponds to pressure
    at node (label) 37579.

    When this ratio is too large, machine round-off errors may become so
    severe that stable models become unstable.

*** WARNING *** CODE ADF2006:
    Model may be unstable! Ratio 7.8769E+12 of largest to smallest diagonal
    elements in factorized coefficient matrix is greater than 1.E+11. The
    largest diagonal element 6.59802E+10 corresponds to
    y-velocity at node (label) 51222 and the smallest
    diagonal element 8.37639E-03 corresponds to pressure
    at node (label) 40415.

......

wild_field

还要检查载荷，边界条件及模型初始条件的正确性。