Numerical study of turbulent slot jet impingement cooling on a semi-circular concave surface

An investigation of the flow field and heat transfer characteristics of a slot turbulent jet impinging on a semi-circular concave surface with uniform heat flux has been carried out numerically in this study. The turbulent governing equations are solved by a control-volume-based finite-difference method with a power-law scheme and the well-known k–ε turbulence model and its associate wall function to describe the turbulent structure. In addition, a body-fitted curvilinear coordinate system is employed to transform the physical domain into a computational domain. Numerical computations have been conducted with variations of jet exit Reynolds number Re2B (5920 ⩽ Re2B ⩽ 23,700), dimensionless jet-to-surface distance H/B (0.5 ⩽ H/B ⩽ 12), dimensionless jet width B/D (0.033 ⩽ B/D ⩽ 0.05) and the heat flux q″ (1663 W/m2 ⩽ q″ ⩽ 5663 W/m2). The theoretical model developed is validated by comparing the numerical predictions with available experimental data in the literature. The variations of local Nusselt numbers along the semi-circular concave surface decrease monotonically from its maximum value at the stagnation point. The numerical results show that the local Nusselt numbers are reasonably predicted with a maximum discrepancy within 15%. As the Reynolds number fixes, the effect of the impingement distance (H/B) on the average Nusselt (Nuavg) is not significant except at low H/B = 0.5. This study provides fundamental insight into turbulent slot jet impingement cooling on the semi-circular concave surface.