PARTICLE IMAGE VELOCIMETRY FOR THE MEASUREMENT OF MEAN AND ACOUSTIC PARTICLE VELOCITIES

A novel method is outlined which allows measurement of the amplitude o f oscillation of a sinusoidal sound field and the mean flow using part icle image velocimetry. The method involves simplifying the interrogat ion area in such a way that the autocorrelation function contains tour significant peaks. The accuracy is of the order of half pixel resolut ion, once a constant offset related to the non-continuous nature of th e probability function of a sine wave is taken into account. This cons tant, which originates from the pixelation of the image, is shown to b e 0.85 pixels.