Koray KARABULUT, Dogan Engin ALNAK, Ferhat KOCA

Investigation of Heat Transfer from Heated Square Patterned Surfaces in a Rectangular Channel with an Air Jet Impingement

Heat transfer is a very important precaution for proper design and safe operation of electronic packages and systems. Impinging jets are usually used to solve thermal problems of electronic components in industry due to providing a good heat transfer performance. In this study, cooling of copper plate with five square patterned surfaces inside a rectangular channel comprising of one open and three blocked sides was numerically investigated by using a single air jet flow. The numerical computations were performed by solving a steady, three-dimensional Navier-Stokes equation and an energy equation by using Ansys-Fluent 17.0 software program with k-ε turbulance model. Air was taken as working fluid with inlet temperature of 300 K. A constant heat flux with 1000 W/m2 was applied to square patterned surfaces while the top and side surfaces were adiabatic. The study was carried out for different Reynolds numbers (Re) of 4000, 6000, 8000 and 10000 and different jet-to-plate distances (H/Dh) of 4, 6, 10 and 12. The numerical results agreed well with the numerical and experimental datas of study existed in literature. The results were presented as the variations of the mean Nu numbers and temperatures for each square patterned indentation surface. The temperature and velocity distributions of jet fluid flow and mean temperature and Nu values of whole five square patterned surfaces and value of air jet outlet temperature were also researched for different Re numbers and H/Dh ratios. It was seen that increasing the Re number increases the Nusselt number for all cases. Average Nusselt number increases of 59.28% from Re=4000 to Re=10000 for H/Dh=4. However, Nu number was less sensitive to H/Dh ratio in the range of H/Dh=4-12. Average Nusselt number decreases of 9.11% from H/Dh=4 to H/Dh=12 for Re=6000. The highest average Nusselt number was attained for Re=10000 and H/Dh =6.

Keywords:

Impingement Air Jet, Patterned Surface, Square Channel,

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