[Souviktor]

Hi all,

I am simulating a conjugate heat conduction problem in which a fluid is inside a glass tube having very large wall thickness.So I want to study the conduction through the wall as well as through the fluid.
So I have created an axisymmetric model in gambit.Now,the problem is setting of boundary condition for the internal surface of the glass tube.This surface is in contact with the fluid as well as the glass tube.

If I set it as wall what should be the thermal b.c at this wall?
If I set it as interface there is initialization error in fluent,

The heat flux is applied at the outer boundary of the tube.
If I apply wall b.c at the internal tube wall, then the heat does not conduct to the fluid as the default b.c in fluent is adiabatic wall b.c.
I am confused.can anyone please help?