Mass Flow in CFView
 

Hello,

can anyone tell me how I get the Quantity "mass flow" in CFView of Numeca? I am interested in the mass flow of the pitch averaged view.

Thanks a lot.
Greetings

Hi Peter,

in general you can access the mass flow by selecting any quantity. In the left lower part of the GUI there's a section "Integrals". Here you can compute integrals and averaged values of the selected quantity, but also the mass flow.

But I am not sure if the mass flow can be accesses in the pitch averaged view (or if it makes much sense). To analyse the mass flow I normally create cut planes (ijk or xyz) in the 3D view and analyse the mass flow at these planes. Secondly, mass flows at inlet, outlet and rotor-stator interfaces (if IWRIT is set to 1 (FINE/Turbo)) are written in the .mf file in the computation directory.

Please feel free to describe in more detail what you exactly plan to do.

Kind regards
Holger

Hello Holger,

thanks for replying.
I want to get the values of mass flow at certain radial positions of inlet and outlet of a rotor blade. Can I get theses values with cutting planes?
Where can I find the IWrit option in FineTurbo?

Thanks a lot.
Peter

Dear Peter,

is it a radial or axial machine? In case of an axial machine you can create a blade to blade cut (Strg - b) in the 3D view. Then switch it from "blade to blade" to "cross stream". Then you modify the meridional coordinate to create a cut plane. In the surface tab (top left in the GUI) please select only this cut and select a random value. As mentioned before you can calculate the mass flow through this surface at integrals -> mass flow.

Is this a useful solution for you?

Kind regards,
Holger

Please switch to expert mode in the top right corner. In the computation steering tab you can change the integer expert parameter IWRIT.

Yes this was useful for me.
I git another question, but I'll open e new thread.
Thanks for your help.

Okay thats good. I thought about the problem and maybe I've got a better solution. You could work with an IJK-plane, which covers roughly the desired radial position you are interested in.
At first please click the boundary of the desired domain to get its number (lower right corner), then go to Geometry -> IJK plane. You can switch through the ijk-coordinates of the desired domain and even define a range (for example j only between 14 and 15 in my example). This yields a "striped" surface normal to the flow direction. By selecting only this surface you can access the mass flow of through this stripe (=at a defined radial position).

Unfortunately, the radial height of the stripe depends on the grid.

Another solution could be the value "weight" in the top left turbomachinery view (pitch averaged view), as it is nothing else than density*Vxyz (or Wxyz). However, please take note that it does have the unit kg/(m^2*s) and not kg/s like the mass flow. So it can be seen as a mass flow related to 1m^2.

Kind regards
Holger