hi_cfl error at open cell

Question

Hi Chris,

I come up with a cfl error everytime I am adding up an open boundary (as spillway cell) into my reservoir grid. The hi-cfl error always is shown to occur at the land cell immediately next to the open cell. Without any open cell, everything works fine! here is the error log:

*** Error in `./aem3d_openmp.exe': double free or corruption (!prev): 0x00007f0a7c000c50 ***
 ***** FATAL ERROR **** FATAL ERROR **** FATAL ERROR *****
 * in subroutine sl_momentum_hi_cfl                              
 * ELM method stopped before complete
 *  Cell:        16697
 *  ijk:           92           9          55
 *  uvw:  -6.2761414E-05  8.9298388E-05  -7.707775
 *********************************************************

and my open cell coordinates are:

1001 open_cell spillway

91 7 :

92 7:8 :

Answer 1

Hi Behnam,

Is there a large drop from your spill level to your open BC height?

The way we are doing spillways now is using the dynamic boundary conditions.   

eg: Something like below will do a dynamic outflow bc at weir height of 15m for a weir of width 20m on BC 301.

<?xml version="1.0" encoding="UTF-8"?>
<AEM3DDynamicBC>
  <Variable>
    <name>h</name>
    <i>6</i>
    <j>28</j>
    <key>HEIGHT</key>
  </Variable>
  <Variable>
    <name>w</name>
    <key>CONSTANT</key>
    <constant>20</constant>
  </Variable>
  <Range_Variable>
    <name>h</name>
    <i>6</i>
    <j>28</j>
    <key>HEIGHT</key>
  </Range_Variable>
  <Range>
    <maxValue>15</maxValue>
    <script>0</script>
  </Range>
  <Range>
    <minValue>15</minValue>
    <maxValue>40</maxValue>
    <script>0.5*SQRT(2*9.81)*w*((h-19)**1.5)</script>
  </Range>
  <Range>
    <minValue>40</minValue>
    <script>4000</script>
  </Range>
  <bc>301</bc>
  <bc_key>OUTFLOW</bc_key>
</AEM3DDynamicBC>

Comments

I think Chris meant 15 instead of 19 in the formula below:
    <script>0.5*SQRT(2*9.81)*w*((h-19)**1.5)</script>