Numerical Simulation of Formation and Movement of Various Sand Dunes

Abstract

In this paper, four types of sand dunes are simulated by using Large-Eddy Simulation (LES) method. In the flow direction and span direction cyclic boundary conditions are imposed for velocity and pressure. The movement of the sand dunes which are well know as barchan dunes, transverse dunes, linear dunes and Chinese wall have been investigated. The numerical method employed in this study can be divided into three parts: (i) calculation of the air flow above the sand dunes using standard MAC method with a generalized coordinate system, (ii) estimation of the sand transfer caused by the flow through the friction, (iii) determination of the shape of the ground. Because the computational area has been changed due to step (iii), steps (i)–(iii) are repeated until prescribed times.