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April 21, 2020, 19:56 |
Grid Motion in Parallel
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#1 |
Member
j
Join Date: Apr 2020
Posts: 34
Rep Power: 0 |
Hi, I'm having a small issue with my dynamic mesh UDF. I am running in parallel and end up doing some calculations to figure out how much to displace each wall vertex on my mesh. It seems to work fine except when I hit update dynamic mesh and run 1 iteration, it performs the grid motion twice. I also display a message for how much volume total I am displacing. When I hit update dynamic mesh, the message displays twice. The first tie it shows the correct volume to move the mesh. The second message shows exactly double the first volume. As shown, I use a += statement to loop through all the cells to get this value. This tells me that the entire thing is running twice for some reason. I'm running on 28 processors. The calculations across the processors works great, but again, it's like the function runs twice when I hit update dynamic mesh. Any ideas why this might happen? Could this be something to do with how node 0 communicates with the host? Maybe it's running my entire UDF twice?
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April 22, 2020, 04:42 |
Loop
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#2 |
Senior Member
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To debug it, print myid within Message. This will tell you whether the message is being printed by host or node, and which node, of course. And that might be helpful in determining why the code runs twice.
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April 22, 2020, 05:15 |
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#3 |
Senior Member
Alexander
Join Date: Apr 2013
Posts: 2,363
Rep Power: 34 |
it is recommended to use
#if RP_NODE for global summation #if PARALLEL means nodes + host however, you have (I_AM_NODE_ZERO_P) so your message function should be executed just once Usually, Message0 is used to write output to console in case of parallel consideration If it doesn't help, show the whole code, may be problem is somewhere else
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dpm, grid motion |
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