| Summary: | 碩士 === 國立成功大學 === 機械工程學系碩博士班 === 94 === The 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 power-law scheme and the well-know k-epson turbulence model and its associate wall function to describe the turbulent structure. In addition, 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, dimensionless jet-to-surface distance H/B, dimensionless jet width B/D and the heat flux. The theoretical model developed is validated by comparing the numerical predictions with available experimental data in the literature. In these studied ranges, the variations of local Nusselt numbers along the semi-circular concave surface decrease monotonically from its maximum value at the stagnation point except that at low H/B=0.5, the maximum Nu shift to S/B=1.5. 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 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.
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