Turbulence structure in the immediate vicinity of the shear-free air-water interface induced by a deeply submerged jet

Abstract

A PIV based technique is developed to perform flow measurements in the vicinity of the air-water interface of a submerged confined jet. Both the interface movement and the velocity field immediately beneath it are measured simultaneously. A detailed turbulence structure in the surface influence region is thus obtained. Flow parameters evaluated without and with respect to the interface are quantified and compared against previous works obtained using the conventional Eulerian-based instrumentation which do not account for the interface fluctuation, and checked against analytical model characterizing the turbulence close to a assumed flat air-water interface.