Conditional Sampling in Turbulence Measurement

Abstract

(a) Shear flows which exhibit a turbulent-nonturbulent interface; (b) Shear layers perturbed by interaction with another field of turbu­ lence; (c) Quasi-periodic or periodic flows (these include flows behind pass­ ing blades in rotating machinery, boundary layers over a solid or liquid surface with stationary or progressive periodic waves, and more generally flows subjected to either internal or external peri­ odic perturbations); (d) Coherent structures in different shear flows (these structures are currently receiving close attention by the turbulence community in view of their importance to the flow dynamics).