【讨论】请教收敛问题

upclhl

在做一个高速流体喷射分析时，出现以下错误，不知如何解决？网格划分基本是均匀的，为什么总是发散呢？如何提高收敛性？请高人指点。
H:\adina\squar_jet.dat
Checking prerequisite files...
Initializing ... Stage 1
Initializing ... Stage 2
Allocating memory ...
Starting Solution Process ...
Allocated memory      for the program without sparse solver =   419.4mb
Currently used storage by the program without sparse solver =    29.8mb
Storage used by sparse solver =    52.4 mb
Out-of-core sparse solver is used
Computation starts ...
Time step      1   Time = 1.000000E-02
  
*** WARNING *** CODE ADF2006:
  
Model may be unstable! Ratio 1.6886E+14 of largest to smallest diagonal
elements in factorized coefficient matrix is greater than 1.E+11. The
largest diagonal element 1.95797E+05 corresponds to
y-velocity at node (label) 4530 and the smallest
diagonal element 1.15949E-09 corresponds to pressure
at node (label) 7987.
  
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.
  
*** WARNING *** CODE ADF6033:
  
Absolute residual 1.57E+16 of pressure is too large.
  
*** WARNING *** CODE ADF6033:
  
Absolute residual 8.42E+24 of turbulent KE is too large.
  
*** WARNING *** CODE ADF2006:
  
Model may be unstable! Ratio 1.2287E+31 of largest to smallest diagonal
elements in factorized coefficient matrix is greater than 1.E+11. The
largest diagonal element 1.04895E+13 corresponds to
y-velocity at node (label) 10745 and the smallest
diagonal element 8.53659E-19 corresponds to pressure
at node (label) 10750.
  
Job Stopped.

huilan

使用的ADINA是哪个版本，有无.in文件？

upclhl

谢谢huilan的回复，用的7.5.4，.in文件附后，麻烦帮忙分析一下，非常感谢！

aerospace

应该是边界条件的问题。
边界条件检查是否有物理上矛盾的东西！