OpenFOAM has two solvers (chtMultiRegionFoam and chtMultiRegionSimpleFoam )  for the simulation of heat transfer across different materials.  When a solver has the keyword simple in its name in OpenFOAM, it means it uses SIMPLE algorithm for pressure-velocity decoupling, Moreover, it represents it is a steady solver.

here, I mention two conjugate heat transfer problems I’ve done using these solvers:

• transient heat transfer between two co-center pipes.

 

• airflow over heated obstacles is simulated based on Ref [1]. The velocity contour and solid temperature are shown below

 

References

1. Young, T.J. and Vafai, K., 1998. Convective flow and heat transfer in a channel containing multiple heated obstacles. International Journal of Heat and Mass Transfer, 41(21), pp.3279-3298.