Learning Forum

[Morizio]

Hi All,

I'm using ANSYS fluent 19.1 to simulate a reactor with around 15 reactions in it. its a system of 15 reactions mechanism and I wrote a UDF for this purpose. The simulation is working well in my PC without any error. However, as it takes a long time, I decided to run it on a High-Performance Computing (HPC- Compute Canada) system. I've used the same Case file in a remote cluster to reduce the time...

However, I found that although the HPC cluster system is faster in number of Iteration, the response change (concentration in my case) per iteration is lower than my PC!!!

In other words, It needs higher iterations to reach the same concentration in the HPC system (as it can be seen in the following figure). it should be noted that the case file is the same in both systems!

Do you have any suggestion to solve this problem?

 

Thanks,

Morizio

[Rob]

Are you running parallel on your PC too?

[DrAmine]

TTo ADD:

Whenever I see this kind of posts the first thing which comes to my mind is whether the runs are deeply converging (residual very low, low imbalances, constant monitor profiled). The second thing is to check if the issue occurs on other number of cores and then might be related to partitioning. Have always a look under menu Parallel>Partitioning and Load Balancing>Print Active whether the deviations are small enough across the partitions.