摘要
Basic fluid mechanics and stochastic theories are applied to show that the concentration distribution of suspended solid particles in a direction normal to the mean streamlines of a two-dimensional turbulent flow is greatly influenced by the lift force exerted on them in the vicinity of the wall.Analytic solution shows that,when the direction of the mean flow is horizontal,the probability density function p(y,t)for random displacements of the particles will have a maximum value at a point from the wall where the perpendicular component of the lift force precisely balances particle gravity.Interpretation of experimental observations is presented using this theory.
Basic fluid mechanics and stochastic theories are applied to show that the concentration distribution of suspended solid particles in a direction normal to the mean streamlines of a two-dimensional turbulent flow is greatly influenced by the lift force exerted on them in the vicinity of the wall.Analytic solution shows that,when the direction of the mean flow is horizontal,the probability density function p(y,t)for random displacements of the particles will have a maximum value at a point from the wall where the perpendicular component of the lift force precisely balances particle gravity.Interpretation of experimental observations is presented using this theory.