Abstract
Background oriented schlieren (BOS) technique is the novel image processing technique which enables us to measure the quantitative density distribution in compressible or convective flow field. The colored-grid background oriented schlieren (CGBOS) technique has been developed in our advanced approach using colored-grid pattern as a background image. The CGBOS computed tomography (CT) method is based on the multi-images of 2D quantitatively integrated distribution data of refractive index gradient around a test model in supersonic flow. These images are calculated by the distortion of the background stripes image. We picked up a square-pyramid nose (asymmetrical) model for our CGBOS experiment. The blowdown-type supersonic wind tunnel of JAXA-ISAS was used, and from 19-2D images of every 5 degrees, we reconstructed the 3D density gradient information from CGBOS and ART-CT technique.
