Determination of the coefficients of Langevin models for inhomogeneous turbulent flows by three-dimensional particle tracking velocimetry and direct numerical simulation

作者：Walpot R J E^*; van der Geld C W M; Kuerten J G M

来源：Physics of Fluids, 2007, 19(4): 045102.

DOI：10.1063/1.2717688

A promising and, in terms of computer power, low-cost way of describing flow properties such as turbulent diffusion is by Langevin models. The development of such models requires knowledge of Lagrangian statistics of turbulent flows. Our aim is to determine Lagrangian statistics of inhomogeneous flows, as most turbulent flows found in practical applications are inhomogeneous. The present paper describes how a Lagrangian measurement technique, three-dimensional particle tracking velocimetry, has been developed and applied to the most common example of inhomogeneous flows: turbulent pipe flow. A new direct numerical simulation (DNS) code has been developed and experimental results have been compared with results of this DNS code. The results concern Eulerian and Lagrangian velocity statistics at two Reynolds numbers. Based on these, coefficients of the Langevin model have been determined and physical consequences for Langevin modeling and turbulent dispersion have been explained.

• 出版日期2007-4