Abstract
The background oriented schlieren (BOS) technique is one of the visualization techniques that enable the quantitative measurement of density information in the flow field with very simple experimental setup. In recent years, CBOS (Colored Background Oriented Schlieren) technique using colored random dot pattern for background is developed to improve the performance of conventional BOS technique using monochromatic random dot pattern, and it is applied to various measurements of flow. On the other hand, Colored-Grid Background Oriented Schlieren (CGBOS) technique using colored-grid pattern for background is developed and applied to the measurement of supersonic flow field. CGBOS is based on the image processing technique developed for the analysis of finite-fringe interferogram. This paper describes the comparison of the measurement result between CBOS and CGBOS. Measurements of Mach 3.0 flow around a blunt body with a spike were performed for both CBOS and CGBOS at supersonic wind tunnel at ISL with same optical arrangements.
