COOLING EFFECT OF SEVERAL RODS ON A HEATED FLAT SURFACE BY IMPINGING JET

This paper describes the heat transfer and flow characteristics on / around several rods set on a flat heated surface by a single circular impinging jet. A nozzle is located (1) above the space between rods or (2) above a center rod. This system corresponds to the cooling of electric device. Three dimensional unsteady governing equations were solved numerically by using a finite difference method. The SIMPLE algorithm was employed to solve the coupling between the continuity and momentum equations through the pressure term. The QUICK scheme was implemented to calculate the convection flux through the cell faces of control volumes. Numerical conditions are Reynolds number Re=1500, the dimensional space H/D=0.67, a side of a rod=10mm and a pitch of two rods in lattice arrangement Pi=20mm. The velocity vector and temperature distribution were obtained and this temperature distribution was visualized using thermosensitive liquid crystal. The local Nusselt numbers on impingement surface and several rods were evaluated. The second nozzle position was effective for heat removal.