hello everybody, 

 

I'm new CFX user ans i have to make flow simulation of centrifigical pump and analyse results principaly pressure and velocity in outlet. 

 

The boundaries conditions are: 

- Pressure inlet: 13 000-30 000 Pa

- Mass flow outlet: 100 g/s

- Impeller angular velocity: 10 000 rev/min

- Material: Water

 

I have some questions about setting of analysis: 

 

1) What is the principaly difference between Transient analyse and Steady state ? 

 

2) Steady state analyse  can be right for pump simulation knowing that the Reynolds number is very hight ( Approximatively 44 000)

 

3) In Transient analyse case how to set proprely the  "Time duration" and "Time Steps". I seen that I have to calculate before one parameter wich is: Courant Number. What is this parameter and how to calculate it? I know that it's depends of the smallest mesh element and velocity, but what is this Velocity ? 

 

4) The last question is about Convergence in Transient analyse case: How knowing exactly that the results have converged. 

 

Thank you in advance for all and I'm here for any question and information.

 

Massinissa.