Structure of stratified flow beyond a thin vertical plate according to data of the Schlieren method and echo-sounding

摘要

A combined-modeling method that involves acoustic and optical instruments, the velocity field being visualized on the basis of density marks, was used to study the stratified-flow structures. A laboratory setup including a basin filled with water stratified over salt, a Schlieren instrument possessing a 23-cm field of vision, a high-frequency sonar were also used. A contact electric-conductivity profilometer was also applied. The laboratory basin was permanently filled with stratified liquid by sequentially displacing it from below. The acoustic probing was performed in the vertical direction. The distance between the sonar antenna and the wake axis attained H = 12.5 cm, with the sound beam diameter in the given horizon being 6 cm. The wake height rises monotonically, and the reduction of the optical contrast is accompanied by a decrease in the echo signal.