NUMERICAL STUDY OF MULTIPLE IMPINGING SLOT JETS WITH AN INCLINED CONFINEMENT SURFACE

Abstract

This study presents numerical predictions on the fluid flow and heat transfer characteristics of multiple impinging slot jets with an inclined confinement surface. A nonorthogonal body-fitted coordinate system was used to handle the complexity of the geometry, and a control volume based finite difference method was employed to solve the governing equations. Two turbulence models are used to describe the turbulent structure: the standard k-ε turbulent model associated with wall function and the Lam-Bremhorst version of the low-Re k- ε model. The parameters studied include the angle of inclined confinement surface θ(0° ≤ θ ≤15°) and entrance Reynolds number (11,000 ≤ Re ≤ 21,000). The numerical results show that the maximum local Nusselt number and maximum pressure on the impinging surface move downstream while the inclination angle θ is increased. The maximum local Nusselt number decreases while the value of the local Nusselt number downstream increases with increasing inclination angle θ. The calculated streamline contours are also noted, in that the entrance Re has little effect on the size of the recirculation region, but the inclination angle θ has a significant effect on the recirculation zones. Inclination of the confined surface to accelerate the fluid flow was found to level the local Nusselt number distribution on the impingement surface.

Notes

Address correspondence to Associate Professor Yue-Tzu Yang, Department of Mechanical Engineering, National Cheng Kung University, Tainan, Taiwan 701, Republic of China. E-mail: [email protected]. edu.tw