Pulsed radial jet reattachment nozzle heat transfer to a flat plate

An investigation was made into the heat transfer characteristics of Pulsating Radial Jet Reattachment, PRJR, on a flat impingement plate. A 41 mm 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. In this paper we present time averaged Nusselt number data as a function of pulsation frequency, amplitude, nozzle exit angle, exit gap Reynolds number, and nozzle height. A comparison of Nusselt numbers obtained from RJR and PRJR nozzles is presented.