Assessment of Computational Fluid Dynamic Modeling of Multi-Jet Impingement Cooling and Validation with the Experiments

Abstract

The current study involves numerical and experimental investigations of circular in-line jets impinging on a heated flat plate. The generic configuration is characterized by 9 jets, each with a diameter of D=0.0152 m. The jets are influenced by a self-generating crossflow and are positioned at a nozzle-to-plate distance (H/D) of 5 and a jet pitch (p/D) of 5. The steady Reynolds-Averaged Navier-Stokes (RANS) simulations are performed for turbulent jet Reynolds numbers with the DLR in-house CFD code TRACE. The Menter k-$\omega$ SST model is applied for turbulence modeling and the turbulent scalar fluxes are modeled based on the Reynolds analogy for a constant turbulent Prandtl number. To gain a closer insight into the impingement jet physics, high-resolution near-wall velocity and thermal fields are obtained through Large Eddy Simulations (LES) and measurements from the Particle Image Velocimetry (PIV). Focus is laid on the comparison of RANS results with the LES data and the experimental data. The results exhibit a qualitative similarity between the simulations and the experiments. Furthermore, correlations of the Nusselt number from the literature are used to validate the simulation results.