Large-eddy simulation of turbulent wavy boundary flow—illustration of vortex dynamics

Abstract

Large-eddy simulation (LES) is used to investigate three-dimensional turbulent flow over a wavy boundary. An efficient immersed boundary method (IBM) for simulating turbulent flows in complex geometries is presented. The method is based on a finite-volume approach on a non-staggered Cartesian mesh and a fractional-step method. A force is applied on the body surface through an immersed ghost-cell method. Both steady and unsteady flows are simulated. A steady flow simulation provides not only the mean and turbulence statistics but also visualization of the Görtler vortices. The simulation shows that Görtler vortices are formed by a sequential vortex reconnection process and broken down due to vortex separation. The unsteady oscillatory flow displays the three-dimensional vortex formation/transport cycle which is shown to be important for sediment transport. The turbulent structure is fully three-dimensional and is clearly seen from the current animations.

This paper was chosen from Selected Proceedings of the Third International Symposium on Turbulence and Shear Flow Phenomena (Sendai, Japan, 24-27 June 2003).

Present address: Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD 21218, USA.

Notes

Present address: Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD 21218, USA.