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Dimitriy December 17, 2004 07:58

Force import in CFX
 
Hi every one

Let me explain my problem. For example I have a cubic volume (domain). All of the cube's boundaries are walls with different temperatures so that the fluid flow is entirely within the domain and driven by thermal convection. (I do not have inlet, outlet.. boundaries, there are only walls with different temperature.) I need to import a distributed body force which operates within the domain that tries to change the convection motion of the liquid. Please tell me how to implement the force data in the CFX

Rui December 17, 2004 08:25

Re: Force import in CFX
 
Hi,

You have to create a sub-domain, which shall include the whole domain. Then create a momentum source, which you may set as a constant or as an expression function of the variables you want.

May I ask what force is that, trying to change the convection motion?

Regards,

Rui

Dimitriy December 17, 2004 08:56

Re: Force import in CFX
 
Hi Rui

Force electromagnetic Liquid liquid metal

I have a date of force distribution as vector matrix (value and direction of force are different at different points of domain) it is not a constant or function.

What shall I do in this situation?

Regards,

Dmytro

Ribeiro December 17, 2004 15:06

Re: Force import in CFX
 
Hi Dmitri

You should define a User Function on CFX-Pre. Use the Option parameter Interpolation (Data Input). Then choose in interpolation Data Option Three Dimensional. Right-click on Coordinate-Value frame and choose Import... Indicate your file.

You should be aware that your file must be in the CFX format. Read the documentation.

Regards,

Ribeiro

Dimitriy December 21, 2004 10:26

Re: Force import in CFX
 
Dear Ribeiro

Thank you for your advice.

Only I can not understand a dimension of momentum source. It is kg/m^2s^2 but force is kg*m/s^2.

Dose it mean that in expression should be something else except force?

Redards,

Dmytro

Rui December 21, 2004 16:31

Re: Force import in CFX
 
Hi,

Thats's because the momentum equations have units of Force per unit Volume: (kg*m/s^2)/m^3=kg/m^2s^2. And body forces (as gravity) only make sense as force/volume.

Regards and Merry Christmas,

Rui


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