! AFM and EB-AFM models
! "-C_theta*k/eps*( xi* uT'.Grad u + eta*beta*g_i*T'^2)"
if (ityturt(iscal).eq.2.and.ibeta.gt.0) then
if (itt.gt.0) then
temp(ii) = temp(ii) - ctheta(iscal)*xtt* &
etaafm*cpro_beta(iel)*grav(ii)*cvara_tt(iel)
How can I change this value of ibeta for my fluid?
Moreover how can I check which value is the default one?
ibeta it is a (integer) pointer for thermal expansion coefficient. To access to the thermal expansion coeff you can use this example used inphyvar.f90, I think.
It looks like the parameter ibeta is automatically defined in base/varpos.f90 when idilat=0 or irovar=1.
When idilat=0, the user should provide the thermal expansion coefficient in a user subroutine, such as usphyv (cs_user_physical_properties.f90). Check cs_user_parameters-base.c if you want to set idilat=0.
When irovar=1, the field containing the thermal expansion coefficient is defined automatically. However, the way the code estimate the thermal expansion coefficient from the variable density is absolutely not clear to me. I suspect the thermal expansion coefficient should also be defined by the user inside a user subroutine such as usphyv.