sl_momentum_hi_cfl ERROR

Question

Hi there,

When I run a simulation using AEM3D, I got the following error message.

 * WARNING * No valid area for flow bc  hii Ref: 101
 * WARNING * Flow will enter like rain on entire bc surface
 * WARNING *            3 new cell(s) filled with default value
 * WARNING * No valid area for flow bc  hii Ref: 101
 * WARNING * Flow will enter like rain on entire bc surface
 ***** FATAL ERROR **** FATAL ERROR **** FATAL ERROR *****
 * in subroutine sl_momentum_hi_cfl                              
 * ELM method stopped before complete
 *  Cell:       101266
 *  ijk:           16          34          70
 *  uvw:    110.8826      0.0000000E+00 -1.7928038E-02
 *********************************************************
 ***** FATAL ERROR **** FATAL ERROR **** FATAL ERROR *****
 * in subroutine sl_momentum_hi_cfl                              
 * ELM method stopped before complete
 *  Cell:       176364
 *  ijk:           22          40          57
 *  uvw:  -7.6805929E-07  0.0000000E+00  -3.936558

But the K =70 point is far above the water surface (= 187.5 m).

The lowest bathymetry is 138.55 m and dz=1m for all.

The heights of the points for the error message are

200.83 m for (16, 34, 70) and 186.1 m for (22, 40, 57).

Is there any advice to solve this error?

Hiroshi

Answer 1

I came across similar problem days ago. In my case the problem was related to the way I defined boundary condition for water release. Flow release elevation at one of my boundary cells was higher than the water surface elevation at the time. Once I corrected that, the simulation went smoothly and didn't see that error any longer.   

Seyoum

Comments

Hi Seyoum, thank you for the comment.
The celles which had the CFL problem were not BC cells. They are adjacent cells to the cells for flow_multi_sides.
First I could run the simulation. Then I only changed to run the simulation with light extinction coefficient variation, which caused a problem.
Still I could not figure out the problem.
Cheers,
Hiroshi

Answer 2

Hi Hiroshi,

As Seyoum said, it seems that you should redefine to which cells you apply the flow for the bc.

Regarding the sl_momentum_hi_cfl it says hi_cfl which means that you have to decrease your time step.

Try with a smaller time step and decrease it if you still have the error.

I hope it helps,

Bill

Comments

Hello Bill,
Thank you for the comment.
As I commented for Seyoum, the cells are not BC cells.
If the cells are in the water, decreasing the time step will work.
My case seems to be different.
Maybe I did some silly thing.
Warm regards,
Hiroshi

Answer 3

I could solve the problem by make values larger in InflowMinDepth.dat and Inflow MaxDepth.dat

Hiroshi