Experimental Study of Multiple Jet Impingement Cooling on a Flat Plate

摘要

Heat transfer to a straight multiple impinging air/water jet is studied experimentally. A 2×2 cm thin copper plate, 1 mm thick was electrically heated and cooled from one side. The temperature was measured on the other side. A geometrical prearrangement of 7×7 arrays in-line with a pitch of 3 mm was tested. The heat flux is varied from 20 to 250 W/cm2 with 0.25 and 0.5 mm diameter jets. The temperature differences between jet exits to test surface is within 700℃ for air jets and 300℃ for water jets. Though the jet impingement using multiple jets is a complicated heat transfer phenomenon, the results were interrelated using a relation in the mathematical form of the Nusselt number which is a function of two exponents, n and m. The exponent (n) shows the effect of Reynolds number for both air and water jets. The exponent (m) specifies the consequences of heat flux on the working fluid and diameter of jet.