PIV algorithms for open-channel turbulence research: Accuracy, resolution and limitations

摘要: Abstract The implementation of PIV for experimental studies in open-channel flows can be challenging due to the presence strong velocity gradients and inclusion solid interfaces captured images. Understanding performance limitations method under these conditions is critical optimising parameters robust interpretation data. optimum algorithm extracting fields from images subject ongoing revision with goal maximising resolution minimising errors, recent advances this regard may particularly beneficial turbulence research. Key steps iterative discrete shift (IDS) image deformation (IDM) algorithms are detailed, fundamental differences between direct cross correlation FFT-based methods explained. It also shown how an determined its modulation transfer function (MTF), MTF manipulated selection intensity weighting windows. random error levels selected demonstrated different flow field conditions, including near boundary region, using simulated