Flow Field Measurement Method by Means of Time-Averaged Contrast of Images

Abstract

A new image measurement method for obtaining time-mean velocity field is proposed. The so-called time-averaged contrast is a statistical parameter of image data. Its characteristics are examined in detail with a simple mathmatical model for particle images. It is found that the variance of image data gives the time-averaged contrast and the velocity of the particles in the case that the averaged intensity of the image data is constant in time. Numerical simulation shows the possibility of practical measurement.