[Feyrisnyannyanz]

Now, I buy quadro k620 to use GPU Accelerator and co-processor Ansys Fluent But it does not. GPU does not help it faster than use cpu only.Like not having a GPU. I want to know what to do to be able to use the GPU to help with calculations. Thank you.

[flotus1]

Even if you get it working correctly, a Quadro K620 probably won't accelerate anything. It lacks memory, memory bandwidth and floating point performance.
I assume you are trying to use it for the SIMPLE solver. In this case you would have to activate the GPU manually in the text user interface IIRC, setting the GPU in Fluent launcher is not enough. But no matter how fast your GPU is, solution times will be longer with the SIMPLE solver.
GPU acceleration in Ansys Fluent