Detailed Heat Transfer Distributions Under an Array of Orthogonal Impinging Jets

Abstract

Detailed heat transfer distributions are presented for an array of in-line jets impinging orthogonally on a target plate with different crossflow orientations. A transient liquid crystal technique was used to measure the detailed heat transfer coefficients on the target surface. Different crossflow directions are created by changing the test section open ends. For each exit orientation, measurements are made at four flow Reynolds numbers between 4.8 x 10 3 and 1.83 X 10 4 . Results show that the now exit crossflow direction significantly affects the flow and heat transfer coefficient distributions on the target plate. Local heat transfer coefficient increases with an Increase in average jet Reynolds number over the entire impingement target surface. Highest heat transfer coefficients are obtained for a crossflow orientation where flow exits in both directions. Nusselt number results are correlated for the various exit flow orientations