EXPERIMENTAL INVESTIGATION OF CONVECTION HEAT TRANSFER FROM ALUMINUM FOAM HEAT SINKS

In the present study, convection heat transfer from arrays of heat sources extended by 10 PPI (Pore Per Inch) open-cell aluminum foam heat sinks inside a horizontal channel has been investigated experimentally. Air was used as the working fluid. Aluminum foams have been placed on discrete copper blocks in a rectangular channel in order to investigate the effect of aluminum foams on electronic equipments performance. The lower surface of the channel was equipped with 8x2 array of aluminum foam heat sinks subjected to uniform heat flux. Sidewalls, the lower and upper walls were insulated. The experimental study was made for Reynolds numbers 531 <= Re-Dh <= 4486 ( for laminar and turbulent flow), modified Grashof numbers Gr(Dh)*=4,2x10(7) to 2,7x10(8) and Richardson numbers Ri=0,008 to 1,5. From the experimental measurements, distributions of Nusselt number were calculated for different Reynolds and Grashof numbers. It is found that heat transfer rate is substantially increased by employing aluminum foam heat sinks with low pore density due to relatively intense air through the aluminum foam heat sinks. As a result of comparisons, using of 10 PPI aluminum foam heat sinks increases the heat transfer rate in the channel between approximately 36% and 70% compared to the rate obtained without the foam heat sinks in a channel.