Heat transfer characteristics of latent functionally thermal fluid flows in the pin-fin Micro channels

Abstract

In view of the cooling problem of high power lasers, the existing traditional working fluids are replaced by the latent functionally thermal fluid. The laminar flow and heat transfer characteristics of the latent heat functionally thermal fluid and that of deionized water in a piece of pin-fin micro channels with height of 4 mm, width 2 mm and spacing 1 mm were experimentally studied. The results show that when Reynolds Number ranges 625~1125, the latent functionally thermal fluid shows better cooling performance and lower wall temperature than the deionized water, and it has an optimum concentration value; Its average Nusselt number is greater than that of the deionized water, and the average Nusselt number increases with the Reynolds Number. To clearly demonstrate the relationship between the average Nusselt number，Reynolds Number，mass concentration and Prandtl number，an experimental formula was further fitted based on the experimental data，the maximum relative deviation is 16.9%， which is acceptable for experiments. Along the length in the direction of flow, there exists an optimal length for a stable local heat transfer enhancement section.