Abstract
A combined measurement of velocity field and surface pressure distribution around a two-dimensional cylinder in a low-speed wind tunnel was conducted using time-resolved particle image velocimetry (PIV) and unsteady pressure-sensitive paint (PSP). We measured spatial distribution of the vorticity fluctuation behind the cylinder as well as pressure fluctuation on the surface of the cylinder. Then we calculated the spatial distribution of coherence for vorticity and surface pressure. Finally, we determined characteristic decay length of coherence in spanwise direction of the cylinder. We obtained good agreement between the characteristic lengths determined by vorticity and by surface pressure. This agreement implies that the unsteady PSP is potentially a good tool for aeroacoustic analysis.
