Ground Effect in Hydrodynamics of a Strip in a Stratified Fluid

Abstract

The paper is devoted to the numerical investigation of stratified flow structure and dynamical characteristics of an imperme- able obstacle moving at some distance from the rigid horizontal surface. At the simplest cases of a plate moving along under- lying plane or in free space the calculation results are compared with the visualizations of exact solution and the Schlieren images of stratified flows in the laboratory experiments. The calculations reveal that accounting for the finestructure effects, i.e. medium stratification and diffusion, which are always present at the natural conditions, can influence essentially upon flow structure, forces and momentum distributions. The obtained results, which have a practical application to ground-effect vehicles and ekranoplans, show the stratification effects may lead to a noticeable increase in drag and decrease in lift of a body moving near the rigid surface.