Abstract
The purpose of this research is performance assessment of Projection type Background-Oriented schlieren (PBOS) method, in order to progress accuracy applied Background-Oriented schlieren method in field experiment. We visualized vortex ring using PBOS, and compared between PBOS, BOS and numerical calculation results. Vortex ring was emitted from diaphragm less shock tube, at shock Mach number 1.50 ±0.01. Projection type background was created by laser speckle using Ar+ laser and concave lens. The experiment results are PBOS and BOS images have coequal analysis accuracy. Key Words: Background-Oriented Schlieren, Laser speckle, Flow visualization, Vortex ring
