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-   -   Ansys Fluent Simulation Warning (https://www.cfd-online.com/Forums/fluent/196690-ansys-fluent-simulation-warning.html)

hellsblade.91 December 12, 2017 10:12

Ansys Fluent Simulation Warning
 
Has anyone ever got such a warning in Fluent : LOW_DEG: Requires 2048 items per warp!!!


What does this interpret ?

GregCFD December 12, 2017 21:33

Quote:

Originally Posted by adasgupta91 (Post 674854)
Has anyone ever got such a warning in Fluent : LOW_DEG: Requires 2048 items per warp!!!


What does this interpret ?

I would guess it's a warning that the model you are using trying to run on your GPGPU has too few elements so it's either unable to run or will be very very inefficient.

This is based on:
LOW_DEG being a low degree of freedom warning, for a FVM formulation is ~the number of cells.

A warp is a Nvidia term (~equivalent to a Wavefront in AMD hardware) for the high level grouping of threads on the GPU, with the 2048 being the number of CUDA cores.

hellsblade.91 December 14, 2017 04:19

Warning Ansys Fluent
 
2 Attachment(s)
The simulation is running and my residuals look to be fine around e-6.

I just get this warning LOW_DEG: Requires 2048 items per warp initially in between some iterations and then its not there.

I am not sure how it affects my results

GregCFD December 14, 2017 04:24

Quote:

Originally Posted by adasgupta91 (Post 675065)
The simulation is running and my residuals look to be fine around e-6.

I just get this warning LOW_DEG: Requires 2048 items per warp initially in between some iterations and then its not there.

I am not sure how it affects my results

That's interesting, can you give us more details on your setup?, For example what kind of hardware your running it on and the setup of the simulation e.g Number of elements, Coupled or SIMPLE, Heat Equation on or off, Adaptive Meshing etc.

hellsblade.91 December 18, 2017 06:06

1 Attachment(s)
My PC on which i locally run the simulns is basically 64 bit Professor , 64 Gb ram 4.20 Ghz

I am running a transient simuln where i am checking the mass flow rate and vel , pressure at my outlet when i have a pressure of 6-24 bar wiith varied no of inlets as in the pic attached (5 inlets in the pic)

I am running the sim on K-epslion Turbulent Model density based transient sim for approx 40 iteration upto 10 seconds


I am getting my results however I am not sure if these warning are affecting my results


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