Daisuke Ono

Optical Measurements of Shock Wave Oscillations in Transonic Diffusers by High-Speed Mach-Zehnder Interferometers

The two dimensional unsteady structure including the interaction between a normal shock wave and turbulent boundary layer in a transonic diffuser is quantitatively and qualitatively visualized using high-speed Mach-Zehnder interferometry. Experiments have been performed at an operating pressure ratio of 1.4 where the freestream Mach number just ahead of the normal shock wave is around 1.1. The normal shock oscillatory characteristics in the diffuser are also investigated by a high-speed schlieren method. Streamwise static pressures on the diffuser side wall have been measured and the time-mean wall pressure distribution in the diffuser is compared with that from the RANS equation with the k- SST turbulent model. The dominant frequency of the normal shock oscillation obtained from the Mach-Zehnder interferometry is quantitatively identical to that from the high-speed schlieren mothod.

Investigations of Underexpanded Moist Air Sonic Jets from Axisymmetric Convergent Nozzles

The structure of the moist air sonic jet issued from axisymmetric convergent nozzles has been experimentally investigated. Static pressures along the nozzle axis for a range of relative humidity from  = 0.35 to 0.98 have been measured by the through-tube system installed in the indraft supersonic wind tunnel. Also, the Reynolds averaged Navier-Stokes equation with the Menters k-SST model for dry air sonic jets ( = 0) has been numerically solved. Effects of the relative humidity on the centerline static pressures in the moist air sonic jets are clarified.