Heat transfer characteristics of a pulsed radial jet reattachment nozzle

An investigation was made into the heat transfer characteristics of Pulsating Radial Jet Reattachment, PRJR, on a flat impingement plate. A 41mm diameter PRJR nozzle was built with interchangeable guides for -10. 0, 10 and 20 degree exit angles. A crank link mechanism was used to generate harmonic exit gap pulsations of 2.54 and 6.35 mm with an adjustable mean gap and 5-30 Hz pulsation rate range. Steady periodic surface pressures were measured on the flat impingement plate beneath a PRJR nozzle to investigate the behavior of the PRJR. Measurements to calculate the steady periodic, local heat fluxes for the PRJR nozzle and local heat fluxes for similarly configured RJR nozzles were made. Correlations were made to determine the location and value of the maximum local heat transfer as a function of the nozzle parameters: Reynolds number, nozzle height, nozzle gap, and exit angle. A seven-coeflScient equation describing the RJR and time-average PRJR local heat transfer profiles was developed. Correlations between the nozzle parameters and the equation coefficients were made.