Recent PIV Studies in Fully Developed Pipe Flow at High Reynolds Numbers

Investigating the coherent structures incl. large-scale and very large-scale motions is still progressing and the definition for the sizes of these structures at high Reynolds numbers in fully developed pipe flow is not clear. Recent studies with intrusive measurement techniques show that the streamwise extension of these structures is highly dependent on the Re-number. They are usually represented in wave length (λ) or wave number (k). It can be observed that the sizes of these coherent structures can reach even couple of meters along the pipe axis. This phenomenon is going to be investigated with Particle Image Velocimetry (PIV) as a non-intrusive measurement technique to validate and compare the results of Hot-Wire Anemometry (HWA)