Simplification of Turbine Flow

Tobias · April 20, 2010, 05:01

Hello!

I want to simulate flow through a turbine. The effects I am looking at have no symmetry in circumferential direction and I want to see how the flow is mixing on his way through the stages. So i have to simplify the problem. There are different options to do this: Choosing only a segment, not the whole circle; Dividing the problem in axial direction by cutting into many parts and calculating apart from each other; Quasi-3D-Simulation by combinig different planes.....
Does anyone have experience, perhaps suggestions for papers or other literature on this topic? Or is this problem very individual, so that I have to find it out for my special case?

Thanks and greetings, Tobias.

Hamidzoka · April 20, 2010, 10:24

Dear Tobias;
it strongly depends to the phenomenon you are to study.
but if you model one segment per stage, you are limitted to use mixing plane method for rotor-stator interaction modeling. this has two weakness es for your case:
1- it just lets the rotor recieve a mean value of upsteam quantities.so some disturbances like entropy and wake flows disappears and are not transported to downstream row.
2-it is only applicable to model axisymmetric flows studies.

one proposal is that you model the minimum integer blades count ratio.
for example if you have 40 rotors and 20 stators, easily model 2rotors and 1 stator. this means one stator can affect two rotors.

regards

April 20, 2010, 05:01	Simplification of Turbine Flow	#1
Tobias New Member Tobias Krawuttke Join Date: May 2009 Posts: 15 Rep Power: 6	Hello! I want to simulate flow through a turbine. The effects I am looking at have no symmetry in circumferential direction and I want to see how the flow is mixing on his way through the stages. So i have to simplify the problem. There are different options to do this: Choosing only a segment, not the whole circle; Dividing the problem in axial direction by cutting into many parts and calculating apart from each other; Quasi-3D-Simulation by combinig different planes..... Does anyone have experience, perhaps suggestions for papers or other literature on this topic? Or is this problem very individual, so that I have to find it out for my special case? Thanks and greetings, Tobias.

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April 20, 2010, 10:24		#2
Hamidzoka Senior Member Hamid Zoka Join Date: Nov 2009 Posts: 118 Rep Power: 5	Dear Tobias; it strongly depends to the phenomenon you are to study. but if you model one segment per stage, you are limitted to use mixing plane method for rotor-stator interaction modeling. this has two weakness es for your case: 1- it just lets the rotor recieve a mean value of upsteam quantities.so some disturbances like entropy and wake flows disappears and are not transported to downstream row. 2-it is only applicable to model axisymmetric flows studies. one proposal is that you model the minimum integer blades count ratio. for example if you have 40 rotors and 20 stators, easily model 2rotors and 1 stator. this means one stator can affect two rotors. regards