Flow Field Visualization with a New Self-adapting Iteration Algorithm

A new self-adapting refraction tomography was applied to quantitative measurement of temperature distribution of a flow field. The flow field was given with an alcohol burner. Moire patterns of flow field were produced and captured with a home-made rotary Moire deflectometer. The information of fringe pattern was extracted by phase unwrapping technique with Fourier transform. The relative projection was obtained by theoretical calculation. The density distribution of axisymmetric flow field was calculated by simple self-correlative algebraic reconstruction technique (SSART) based on deflection angles as projections. Eight projections with equal direction interval by 20 degree were used for reconstructing density distribution of a field section. The relative temperature distribution was figured out by theoretical calculation. The actual temperature values of some points on the section were measured with a thermoelectric couple meter, in order to verify the reconstructed result. As the result, the peak error in lab simulation experiment was 4.5%. So, SSART with refraction angle as projection is a super self-adapting refraction tomography.