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Flavio October 24, 2006 08:48

Multistage simulation
I'm working with a stage of a multistage pump. Supposing inlet flow to be axial, the outlet flow is obviously carachterized by a considerable rotational component. Considering that outlet flow coincides with the inlet flow of the next stage, the simulation now exposed is to be considered representative of the first stage only. Knowing that the multistage pump mounts around 70 stages in series, it is necessary to simulate the flow in the intermediate stages. A solution i considered is to save the outlet flow and introduce it "manually" as inlet condition for a secondary simulation, and so on until a sort of convergence is reached.

My question is: does in CFX 10.0 exist a feature that allows me to operate automatically this kind of iteration and this kind of "convergence check"?


Robin October 24, 2006 09:12

Re: Multistage simulation
If you run these separately, there is no automatic way to make sure it converges. The "automatic" way is to set this up as a multi-stage calculation, solving all stages simultaneously, although 70 stages may make for a large calculation.


TB October 26, 2006 22:25

Re: Multistage simulation
I would imagine that you need to set the boundary condition between interface. Solution convergence could be affected if the boundary condition is not right. Error will just propagate in the next stage. If computational resources are not a concern, I'll suggest you to simulate the entire domain in one go.

Robin October 27, 2006 09:19

Re: Multistage simulation
You can ouptut a BC profile from the outlet of the upstream component and apply it to the inlet of the downstream component. All of this could potentially be scripted and put in an automated loop.


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