Investigations of Heat-Transfer Coefficients for Air Flow Through Round Jets Impinging Normal to a Heat-Transfer Surface

In this paper, empirical equations of local as well as average heat-transfer coefficients of single jet system were derived. Two aspects of multiple jet systems have been studied. One concerns mainly the uniform distribution of heat-transfer coefficients and economy of power consumption. The other concerns the high magnitude of heat-transfer coefficients and the interference among jets. The experiments were conducted at Reynolds number from 103 to 104 and hole size from 1/8 to 1/4 in. diameter. An attempt was made to correlate empirical data to render practical application possible.