Yes, you must mesh the solid part as well so that Fluent can solve for the temperatures at each node in the solid (via the heat conduction equation). When you mesh the solid, the fluid/solid interface nodes have to match as well.

Dear dsking,

I have either meshed the solid zone, but Fluent does not solve the heat transfer at all. Would you help me to understand what is wrong?
tnx

Solution
 

Despite it's been a while since the last comment, I decided to back on the thread and share the solution.
Conjugate heat transfer (2D) does happen but very slowly in laminar flow.
If you want to see the final solution, solve the problem in steady-state mode.
If you select a proper turbulence model you can easily watch both solid & fluid changing temperature in a transient solution. Therefore there is no need to convert the geometry to 3D.
I hope this can help.

hi everyone,
i am Dhaval solanki doing simulation on fin heat transfer from engine cylinder. Here i have coupled fluid solid mesh for conjugated heat transfer between interface. Now i am facing problem in giving constant temperature boundary condition inside cylinder wall, because if i give constant temperature at wall created by conjugated coupled option, it will decouple the wall from fluid.
other one is i am new fluent user i also want to know how to get heat transfer co-efficient and heat flux graph with respect to streamwise direction..
thanks

Hello everyone,

I am also facing the same problem in CHT modeling (2D case) in fluent.
here i have one hot cylinder (250c) and another cylinder is placed beside hot cylinder.
air with velocity 100 m/s at 30c is flowing over the cylinders. now i want to find the temperature of the second cylinder because of convection. i have made grid in solid portion also.

Thanks in advance.