how to call the velocity for using in body force condition

[sebastien ROUQUETTE]

Hi everybody.... this is probably easy to do.. but i m quite new. I'm solving a heat transfer and fluid flow problem. I would like to define a body force that requires both temperature and velocity components... i can get the temperature with "variable Temperature.... but i don"t know the syntax for calling the velocity component 1 and 2...
cheers

today, 23rd february... i try to be more clear in my question...

When we want to use the variable temperature in a boundary conditions: we write in elmerGUI or .sif : Variable Temperature; MATC Real; "0.15*tx"
For the space coordinate, it is Varible Coordinate (with or without 1 2) but for the velocity?
is it : Variable Flow Solution or Variable Flow Solution[Velocity Pressure] ... can we access the variable velocity in order to reuse it as a body force, boundary conditions... if yes how do i need to declare it?
regards

[cemg]

Hi Sebastien,

an example (Reynolds number, 2D, compressible flow, air, ideal gas, Sutherland law for viscosity-temperature relation):

Code: Select all

Body Force 1
  Re_number = Variable Temperature, Pressure, Velocity 1, Velocity 2
    Real MATC "(101325+tx(1))/287/tx(0)*sqrt(tx(2)²+tx(3)²)/(1.716e-05*(tx(0)/273.15)^(3.0/2.0)*(273.15+110.4)/(tx(0)+110.4))"
End

Recall that a fortran UDF will be quite faster than MATC.

Regards,

Cesar

[sebastien ROUQUETTE]

thanks a lot cesar