Heat Transfer Coefficient Dependence on Coolant Temperature For Supercritical CO2 Leading-Edge Jet Impingement

Abstract

Abstract In this work a conjugate heat transfer analysis was performed on leading-edge jet impingement heat transfer with sCO2 as the working medium. The internal heat transfer coefficient distribution, as well as external metal temperature profiles, were evaluated for three different coolant temperatures. These coolant temperatures were 360K (pseudo-critical), 500K, and 650K. The heat transfer coefficient distribution was maximum when the coolant temperature was that of the pseudo-critical temperature (360K). A simulation with air as the working medium, with the highest coolant temperature (650K), was also included in the study. The air working medium case had the highest external metal temperature and the heat transfer coefficient was a whole order of magnitude less than that of the sCO2 working medium at the same coolant temperature. The results of the study conclude that convective effectiveness of jet impingement heat transfer is much more effective for sCO2, due to its thermal properties, than it is for air and impingement effectiveness is maximum for a coolant at the pseudo-critical temperature. The nondimensional parameters used to represent heat transfer effectiveness were also evaluated at the three coolant temperatures. The heat transfer coefficient can be characterized by the inertial heat capacitance scaled by the Stanton number.