Numerical investigation of effects of a flat plate placed against the main flow on mixed convection heat transfer inside a rectangular cross-section channel with the iscrete heat sources on the walls

NUMERICAL INVESTIGATION OF EFFECTS OF A FLAT PLATEPLACED AGAINST THE MAIN FLOW ON MIXED CONVECTIONHEAT TRANSFER INSIDE A RECTANGULAR CROSS-SECTIONCHANNEL WITH THE ISCRETE HEAT SOURCES ON THE WALLS(M.Sc. Thesis)Berzan BEZEKGAZI UNIVERSITYINSTUTE OF SCIENCE AND TECHNOLOGYSeptember 2006ABSTRACTIn this study, the mized convection heat transfer has been investigatednumerically under steady flow conditions for the laminar flow in a horizontalchannell with heat dissipating chips representing electronic components. It iswell known that cooling mechanisms are quite important for the safety ofelectronic systems. Keeping the operating temperatures of electronic systemsbelow the limits, by an effective cooling, mechanism is a function of flowconditions created by the cooling system, geometrical dimensions, the locationof heat dissipating chips and other effects.The present study is a numerical analysis of the effects of a flat plate placed at aposition facing the main flow on the mized convection heat transfer inside arectangular cross-section channel with discrete heat sources at the top and atthe bottom. The flow is three dimensional due to the geometry of the problem.Each of the heat sources has been modelled as a square geometry. Thecommercial softwares named as GAMBIT 2.0 and FLUENT 6.0 have been usedfor the solution of problem. The row-average Nusselt number distribution andthe effects of Grashof and Reynolds on the fluid flow have been investigated forboth of the cases with and without a flat plate. The distributions of velocityvectors and temperature contours have been determined numerically and theresults have been presented in detail.The results show that with decreasing the width height ratio(W/H) the effect offree convection plays a more important role and causes the mixed convectionheat transfer. They also show that the plate placed near the exit of channel mayeffectively decrease temperatures of heaters at the top and bottom compared tothose of the channel without any flat plate placed against the main fluid flow.Science Code : 912.1.080Key Words : Discrete heat sources, mixed convection, heat transfer,Numerical analysis, cooling of electronic equipmentPage Number : 134Adviser : Prof. Dr. Mecit SİVRİOĞLU