Comparing Hot-Wire Measurements and Particle Image Velocimetry of Turbulence Fields Generated by an Active Grid

The potential for flow manipulation through the use of an active grid is vast. In this study, we investigate the effects of six distinct flapping excitation protocols on turbulent flows, employing both hot-wire anemometry and particle image velocimetry (PIV) with a large field of view, measuring close to \(1\,\text {m}\) in the streamwise direction. Our primary focus is on comparing the results, particularly examining spectra and the integral length scale L. While the spectra derived from hot-wire measurements, transformed into wave number space through Taylor’s hypothesis, exhibit strong agreement with spatial spectra from PIV data, we observe a significant dependency of L on the length of the data set.