[Hannah_K]

Hello,

I'm a novice in CFX and I'm looking for a solution in case of creating a p-Q curve of my radial fan.

My plan was to compute Q_max (where p = 0), then create a parametrical model to compute other points of the curve. Sadly, I didn't find a way how to compute Q_max yet, so I'm looking for some advices how to do it.

I tried to use following procedure:
- I've modeled just a section of my fan and used periodicity
- Rotation speed set to 20 000 rot/min
- Inlet and outlet areas defined as openings (I also tried to set those as Inlet or Outlet, both relative pressure 0 [Pa])

This procedure compute a point around the middle of the curve, where p =/= 0, not the Q_max I need.



I would very appreciate the help.


Thank you
Hannah

[ghorrocks]

Don't forget that the rotor speed will also vary across the performance curve. You can't assume a constant speed (unless this device has something to make that assumption appropriate).

There is a lot of information in the CFX documentation on how to model rotating machinery and generate performance maps. Have a look at Solver Modelling Guide, Ch 13 for performance maps, and Ch 16.13 for the best practises guides. In your case the turbomachinery looks most relevant, but the one on numerical accuracy is always relevant.