[neuerzh]

Dear everybody,
When I simulated a turbine using CFX, a notice was appeard in the CFD codes,as followed:
+--------------------------------------------------------------------+
| ****** Notice ****** |
| The non-dimensional near wall temperature (T+) has been clipped |
| for calculation of Wall Heat Transfer Coefficient. |
| |
| Boundary Condition : S_R Side 2 |
| T+ clip value = 1.0000E-10 |
| |
| If this situation persists and you are using the High Speed Model, |
| consider enabling Mach number based blending between low speed and |
| high speed wall functions. You can do so by specifying a Mach |
| number threshold as follows: |
| |
| EXPERT PARAMETERS: |
| highspeed wf mach threshold = 0.1 # default=0.0 (off) |
| END |
+--------------------------------------------------------------------+
So I want to ask about the expert parameter "highspeed wf mach threshold",where is it? Does anyone have an idea how to solve this?

Thanks for your attention.

[ghorrocks]

This means your temperatures have gone bezerk. This could either be numerical convergence problems or real.

If it is numerical convergence problems then you need to consider improving mesh quality, smaller time steps, double precision numerics or other methods to improve numerical stability.

If it is real you need to ensure your material properties are valid over the full range of temperatures you are going to get, and consider the expert parameter the warning message says.