code_saturne User's Forum

hi, every one
how to set the temperature in the wall boundary for gas combustion?
In the subroutine usd3pc.f, it says
   icodcl(ifac,ivar)=5
   rcodal(ifac,ivar,1)=value of temperature
I set
   icodcl(ifac,isca(1))=5
   rcodal(ifac,isca(1),1)=value of temperature
But the result seems to be wrong. what should the v ariable name be here？ “ivar”=？
thanks very much!

Yuan

Hello Yuang Huang,
Using Code Saturne in its standard configuration it is not possible to directly assign a temperature as a boundary condition to a boundary face. It is always the enthalpy which has to be set (which might be indeed more challenging than the approach you used above). What you did is to assign the transported variable isca(1) (which is in your case the mixture fraction) to a certain temperature (in your words: value of temperature) Would you should do is to assign isca(3) (which represents the enthaply) to a certain enthalpy at the boundary face.  However, it is not always possible to provide this information, e.g. due to the lack of knowledge of the gas phase composition. In theses cases there a re different approaches, which allow the user to define a wall temperature i.e., which assign the corresponding enthalpy to the boundary phase. Unfortunately, I can't post these approaches right here. But, have you already considered to take radiation into account performing your simulations ? In usray2.f90 the user is given the possibility to assign a wall temperature. Maybe this helps you.
 
 
 

Thanks, the radiation is not considered to take  into account in my simulations.

when I set
   icodcl(ifac,isca(3))=5
   rcodal(ifac,isca(3),1)=value of enthalpy
The result seems to be the same as that I don't write those two lines of code. Why?