Ray casting method for integral calculation of Computational Flow Imaging

摘要

Computational flow imaging (CFI) uses theoretical predictions of the interaction and transmission of optical waves through theoretical flowfield to generate digital pictures that simulate real observations, but the phase data produced by interferometric, schlieren or shadowgraph is the result of the integration of the refractive index or refractive index gradient along the line-of-sight. The goal of this research is to develop a fast, efficient ray casting method for integral calculation of computational flow imaging (corresponding to shadowgraph, schlieren and interferometric). We use a preprocessing procedure that the whole flow region is divided into new regular blocks in which the voxels are distributed by x and y coordinates to increase the processing speed. The algorithms are generally enough to handle non-convex, curvilinear or irregular grids and cells and grids constructed from multiple grids (multi-blocks grids) of CFD solutions.