J0510202 Four-dimensional density measurement of lateral jet/cross flow interaction field by colored-grid background oriented Schlieren (CGBOS) technique

In the field of flow visualization technique, various methods have been employed to practical use until now. The Background Oriented Schlieren (BOS) technique has been proposed as a new flow visualization method. The most significant point of BOS technique is that quantitative measurement can be achieved with simple setup, while conventional schlieren technique is generally used as qualitative measurement. Besides, the BOS technique requires only camera and background, while other quantitative measurements require a lot of optical elements, time and effort for precise measurement. We have been studying the Colored-Grid Background Oriented Schlieren (CGBOS) technique which was improved from BOS technique using random-dot pattern. In the CGBOS technique, two different colors are used for vertical and horizontal stripes, and displacements in both directions can be obtained from one image. We tried acquiring quantitative four-dimensional density distribution by CGBOS technique using high-speed camera. The CGBOS measurements of supersonic cross flow/lateral jet interaction field were carried out in supersonic wind tunnel at JAXA/ISAS.