Heat Transfer of the Critical Air Flow in a Nozzle : 4th Report, The Flow and Heat Transfer Characteristics of an Accelerated Transonic Air Flow in a Divergent Nozzle

Abstract

This paper is concerned with the theoretical and experimental investigations of the accelerated critical air flow and heat-transfer characteristics in the divergent nozzles in which a sonic point exists midway between the inlet and the exit of nozzle fully taking into consideration the viscous effect. The compressible laminar boundary layer equations are solved numerically using a finite difference method, and a chart of the sonic line and the critical flow rate in a divergent nozzle are shown. The numerical solutions of the local and the mean Nusselt numbers of a critical nozzle are in good agreement with the experimental results. The range of critical divergent nozzles in which a laminar flow extends over the whole region of the nozzles is determined experimentally by the nozzle characteristic number and the divergent Reynolds number.