Turbulence, heat-transfer, and boundary layer measurements in a conical nozzle with a controlled inlet velocity profile

Abstract : Turbulence, heat-transfer, and boundary layer measurements were obtained in a conical nozzle operating in air at a nominal total temperature and pressure of 960 deg. R and 300 psia, respectively. Experimental heat-transfer coefficients were compared to values determined by three prediction techniques; namely, (1) Nusselt number correlation, (2) a compressible boundary layer theory, and (3) an incompressible boundary layer theory. Methods (1) and (2) yielded nozzle heat-transfer coefficients that were appreciably higher than experimental values; however, method (3) predicted the nozzle heat-transfer coefficients very well yielding results that were within about 2 percent of the experimental values at the throat. In part of the investigation a simulated nuclear reactor core turbulence generator installed 3 inches upstream of the cylindrical inlet failed to alter the nozzle heat-transfer coefficients. In addition, the turbulence generator had essentially no effect on the boundary layer temperature profiles in the nozzle.