Experiences of turbulence measurement with PIV*

Abstract

The application of particle image velocimetry to turbulence measurement is described. An analysis of physically necessary spatial resolution is presented by using a model spectrum function. A comparison is made with hot-wire anemometry. Some aspects of spatial filtering and two-dimensional sampling are presented with a comparison to large-eddy simulation. The estimation of time mean turbulence quantities from the measured vector fields in a laboratory mixer is used as an example. The measurement results for two different image sizes at the same position in the flow field are compared with different interrogation area sizes. The assumed dependence of the velocity field on the interrogation area size could not be confirmed. The image size seems to produce dependence in all estimated quantities. The measurement errors are critical for the achieved results.