Assessment of PIV to measure mean velocity and turbulence in open-channel flow

The complementary nature of PIV and LDV, in readily available configurations, is demonstrated along with their strengths and limitations by measurements in the flow over a two-dimensional dune in an open channel. This flow field is well suited to evaluate the relative performance of the two techniques as it contains much of the complexity found in practical hydraulic engineering. Agreement in the data obtained with the two techniques, even in regions of flow reversal and high shear, show that PIV is fast reaching a stage where it can be applied with a level of confidence similar to LDV.