Evaluation of the computational benefits of de-coupling convection and conduction heat transfer on a single impinging jet

An impinging jet on a surface is a conjugate heat transfer problem involving convection and conduction processes. Fully-coupled conjugate heat transfer problems can be modeled using computational fluid dynamics (CFD) at a considerable computational cost. A conjugate heat transfer problem using commercially available CFD tools has been used to calculate the final steady-state ground temperature of a plate subjected to an impinging jet. The computational cost was quantified to be 50 hours 55 minute and 57 seconds using 352 processors of type AMD Opteron 8356 clocked at 2.3GHz on a cluster in Pennsylvania State University. To reduce computational time, the aerodynamic heat transfer effects was decoupled from the plate heat conduction process using finite element approaches that account for Fourier and Newton heat transfer laws. The convection heat transfer is solved using a commercial CFD package, while the conduction heat transfer is solved using a 2D axisymmetric heat transfer finite difference code. Comparison of predictions for each heat transfer process were conducted with previous computational and experimental work available in the literature to verify the proposed approach. The reduction in computational time using the de-coupled approach for a single impinging jet problem is compared to the computational time required for solving a conjugate problem using CFD. The final de-coupled problem was solved in 21 hours 57 minutes and 50 seconds using the same cluster configuration which is a reduction of 56.9% in computation time over the full conjugate heat transfer problem.