Analysis of Coupling Strategies for Conjugate Heat Transfer Problems

Numerical solutions to conjugate heat transfer (CHT) problems present challenges regarding accuracy, stability, and computational cost. The current study presents a detailed analysis of the existing OpenFOAM® CHT solvers, including commentary on the multiple forms of the available governing equations and coupling methods. Subsequently, two modified CHT approaches are proposed: (i) a new partitioned algorithm with improved efficiency, and (ii) the available monolithic CHT solver in foam-extend-4.0 was modified and extended to multiple regions. The performance of the proposed solvers is assessed on several transient test cases with various degrees of coupling strength. The results reveal the superiority of the proposed monolithic approach over the partitioned ones, particularly for problems for more than two regions. It is also found that the new partitioned approach is computationally more efficient than the available partitioned solvers.