Experimental and numerical investigation of convective heat transfer from electronic components in a channel by impinging jets

The aim of this study is to investigate the flow and heat transfer in a rectangular channel during the cooling of a copper plate and an array of electronic components with heat flux by a single impinging air jet. In the first part of the study, the heat transfer from a plate and array of electronic components was investigated experimentally for different Reynolds numbers. In the parametric study Reynolds number was taken in the range of 4000-10000. The highest Nu number was achieved for Re=8000. In the second part of the study, heat transfer from a plate and array of electronic components was investigated experimentally for different heat fluxes. The heat flux was varied between q"=1000-3000 W/m2. It was observed that there are no significant changes in the Nu number with changes in the heat flux. In the third part of the study, heat transfer from a plate and array of electronic components was investigated experimentally for different channel heights. H/Dh was varied as 4, 6 and 10 where H is the channel height and Dh is the hydraulic diameter of the jet inlet. It was observed that in general heat transfer decreases with increasing channel height. The highest Nu number was achieved for H/Dh=4. In the fourth part of the study, heat transfer was investigated experimentally for different vortex promoter-jet inlet distances. In the study, N/L was changed in the range of 0.55-1.50, where N is the distance between the vortex promoter and jet inlet and L is the length of the electronic component. The highest Nu number value was achieved for N/L=0.7. It was observed that heat transfer increases approximately 7% for N/L=0.7 compared to the case without vortex promoter. In the fifth part of the study, heat transfer was investigated experimentally for different vortex promoter lengths. In the study, K/H was changed in the range of 0.5-0.9, where K is the length of the vortex promoter and H is the channel height. It was observed that in the range of K/H=0.5-0.8 heat transfer increases with increasing vortex promoter length. It was seen that for K/H=0.9 due to the increasing boundary layer thickness the heat transfer decreased. The highest Nu number was achieved for K/H=0.8. In the sixth part of the study, heat transfer was investigated experimentally for different jet inlet distance to the second vortex promoter. In the study, W/H was changed in the range of 0.5-1.5 where W is the distance of the second vortex promoter to the jet inlet and H is the channel height. It was observed that using a second vortex promoter has almost no effect on increasing the Nu number in comparison with using one vortex promoter (0,8 %),. The highest Nu number was achieved for W/H=1. In the last part of the study, experimental and numerical results were compared. In addition, the effect of the angular position of the vortex promoter on the Nu number was investigated numerically. It was observed that, for ?=0° the Nu number increased by 7%, compared to the case without vortex promoter. The highest Nu number was achieved for ?=0°. Science Code : 914.1.065 Key Words : Impinging jet, channel, LDA, vortex promoter, heat transfer Page Number : 221 Supervisor : Prof. Dr. Şenol BAŞKAYA