DOI: 10.1615/TSFP3
LES OF 3-D TURBULENT WAVY BOUNDARY FLOW: VALIDATION OF A GHOST-CELL IMMERSED BOUNDARY METHOD
SINOPSIS
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. The reconstruction procedure allows systematic development of numerical schemes that preserve the overall second-order accuracy of the base solver. The accuracy of the current method is validated by comparing with previous boundary-fitted grid results (Zedler and Street, 2001). Both steady and unsteady flows are simulated. A steady flow simulation provides not only the mean and turbulence statistics but also visualization of the Gortler vortices. The unsteady oscillatory flow displays the three-dimensional vortex formation/transport cycle which is shown to be important for sediment transport.