放射状不足膨張噴流の流れ場に関する研究

抄録

A radial jet issuing from a slit nozzle is studied experimentally and numerically in this paper. It is a simple model of the wall jet for an axisymmetric jet when it impinges on a flat plate perpendicularly. The slit nozzle is a spacing between the open ends of two tubes placed face to face with each other. The air is choked at nozzle exit and radial underexpanded jet is formed around the tubes. Both of a front and a side view of the flow field are visualized simultaneously using the shadowgraph method. As the oblique shocks in the jet are formed surrounding the circular tubes, the ring-shaped shocks are visualized in the front view, the cell structure of the jet being in the side view. Oscillation of the flow field with many vortices and a feedback mechanism of density waves around the jet obtained experimentally and numerically are discussed.