Diagnostics of jet flows by using tomographic particle image velocimetry

A modern method of velocity measurement in a flow volume on the basis of few-projections optical tomography and correlation of moving particles is considered. The method is used to measure instantaneous three-dimensional velocity distributions in non-swirling and swirling turbulent jet flows. In addition to measurement of three-dimensional velocity distributions, specific features of this experiment are a larger depth of the measurement region (up to 40 mm) and a higher resolution of cameras (up to 4 MP as compared to previous authors’ tomographic measurements). To verify the correctness of tomographic measurements, the velocity in the plane passing along the jet axis is measured by the Stereo PIV method. The difference between the stereoscopic and tomographic measurements of three components of the mean velocity for the flows considered in this study is smaller than 10%. A three-dimensional vortex structure of the core of a swirling jet is visualized with a spatial resolution of 3 mm.