求助：adina计算出错的原因

zzl6525576

计算目标是 一根管子下端没入水面一下，然后吸水（吸水过程我是在水面施加入口速度，然后管子出水端施加压力为零）。我先用2D流场试算。计算中发现如果管子端口不没入水中，刚刚与水面接触的话可以计算出结果，如图所示
模型与边界条件，我在出口端设压力为零，其余边界用wall。

速度场

而一旦加入没入水中的这部分管子，计算就会出错


错误提示：
*** WARNING *** CODE ADF2006:

    Model may be unstable! Ratio 3.6456E+22 of largest to smallest diagonal
    elements in factorized coefficient matrix is greater than 1.E+11. The
    largest diagonal element 3.87351E+12 corresponds to
    pressure at node (label) 383 and the smallest
    diagonal element 1.06250E-10 corresponds to z-velocity
    at node (label) 2056.

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

    Possible causes are:

       * Solution procedure has been divergent;
       * Ratio of largest to smallest elements is too large;
       * No fixed pressure condition in enclosures;
       * Improper units are used in this model. If this is the reason, you
         may either change the input data in another unit system or use the
         automatically nondimensional procedure by choosing proper scales.
麻烦各位帮忙分析一下是什么原因导致不能计算。上面2图是同一个模型，只是没入水中的一段边界施加不同

zzl6525576

呃   自己顶一下 麻烦大家帮忙看看  我检查了模型感觉没有问题啊