I am trying to simulate a centrifugal pump stage with transient conditions. In this case, Massflowrate and rotating speed of impeller are changing with time. I have set Total time = 1 hr and Time step= 1 min. Maximum coefficient loops are set to 3.

Unfortunately, I am getting Following error:

ERROR #001100279 has occurred in subroutine ErrAction. | | Message: | | Floating point exception: Overflow

Can anyone help me out plz.

Thanks.

Hi,

Your timesteps sound very large for a typical pump. Read the documentation section about Best practices for turbomachinery to give you some pointers.

Glenn Horrocks

Dear Glenn Horrocks,

Reducing time step to 1 second eliminate this error. But If I have to simulate transient behavior of my pump for 3 hours, this means total 60 x 60 x 3 = 10,800 time step iterations and with inside coefficient loop iterations, this problem becomes HUGE!. Any suggestion and idea to simulate pump transient behavior in reasonable time?

Hi,

Why do you need to run for 3 hours? Surely the pump reaches steady state way before then.

Also, in CFD sometimes you just have to run huge problems. That is why CFD is run on supercomputers.

Glenn Horrocks

[motahar]

Hi friends,

I'm simulating a vver-1000 reactor pressure vessel.
When I give pressure change to the interface boundaries, I encounter the same error of overflow.
I'm using the k-e model, and because I'm analyzing the heat transfer in the reactor, I have to use k-e model.
I change the turbulent model to SST and it answered, but can anybody helps me how to solve my problem when using k-e model.

Waiting for your help!