Abstract:  A direct image correction algorithm based on the optical principle was developed to solve flowfield distortion of particle image velocimetry(PIV) measurement within circular tube. Without the restriction of liquid saturation temperature, this method can be applied for the synchronous correction of coordinate and velocity vector, and can correctly recover the image distortion in the vicinity of tube wall. In addition, this method requires no accessorial device. A computer code was developed based on Fortran language, which can be easily applied to other cases as long as changing the relevant input parameters. The method was validated by using a uniform square grid with the max deviation of 3%. And this method can provide a satisfactory correction result for the PIV experiment of cryogenic gasliquid two phase flow.  

Key words: particle image velocimetry (PIV), image distortion, direct correction, circular tube, cryogenic liquid