Experimental study of double‑cavity flow
Résumé
The flow through two facing, identical cavities(double-cavity) is characterized experimentally, as theinflow velocity and the distance between the cavities isvaried. Standard 2D2C particle image velocimetry measurementsin the spanwise mid-plane provide informationon the instantaneous and mean velocity flow fields. LaserDoppler velocimetry measurements at several points in thedouble-cavity domain reveal the global character of thestreamwise fluctuating velocity spectra. The flow is characterizedbased on time series, recorded in the shear layer ofone of the cavities, for a wide range of inflow velocities andintercavity distances. In a detailed spectral study, we showhow the shear layer spectra get affected when the two cavitiesare brought closer together. Based on the experimentaldata, a temporal local linear stability analysis was carriedout, which was able to explain why the frequency peaksfor close intercavity distances broaden and move to higherStrouhal numbers.