Temparature and Pressure Distributions on Plate in Underexpanded Impinging Jets : 1st Report, Circulat Jet Impinging Normal to Plate

摘要

The temperature and the pressure distributions on a plate in underexpanded impinging jets are experimentally and numerically studied in this paper. The experiments were performed by measuring the adiabatic wall temperature using infrared imaging camera and the wall static pressures on the impinging plate and by visualizing density fields using schlieren method. Numerical calculations were conducted by solving two dimensional axisymmetric compressible Navier-Stokes equations and three dimensional compressible Euler equations. The comparison between the experiments and the calculations shows that the decrease in the stagnation temperature is caused by a recirculating flow carrying the cold air from the jet boundary to the stagnation point. The temperature and pressure ; contours on the impinging plate illustrate azimuthal structures for the circular nozzle, which are also confirmed by the three dimensional calculations.