Non-equilibrium processes in non-homogeneous fluids under the action of external forces

Abstract

This paper is devoted to the investigation of stable stratification effects that arise as a result of the combined influence of the external forces and environmental media's non-homogeneity due to the non-uniform distribution of dissolved or suspended matter, temperature, gas bubbles and so on. Such a medium is a thermodynamically non-equilibrium system where non-uniformity of the density flux causes the formation of specific fluid motions that are diffusion-induced flows and internal waves (IW), which are non-existent in a homogeneous fluid. In this paper, we demonstrate numerical calculations on flows’ fine structure around impermeable motionless plates with finite length and uniformly moving sloping plates in the interior of a continuously stratified fluid. The flow patterns are investigated both in the direct vicinity of the plate where compact non-wave boundary layer-like components and jet flows are observed and at long distances from the obstacle where sharp horizontal interfaces and groups of IW are revealed. The flows’ properties are analyzed as a function of the dimensional parameters of the problem, i.e. the value of stratification, the plate's length and its slope angle to the horizon. The calculated flow patterns are compared with the earlier obtained asymptotic approximation of small and large times and high-resolution schlieren images of stratified flows around both motionless and moving sloping plates in the laboratory.