Wind tunnel experiment and CFD analysis of sand erosion/deposition due to wind around an obstacle

A wind tunnel experiment on sand erosion/deposition around a cube was performed to clarify the basic phenomena and obtain validation data for computational fluid dynamics (CFD) analysis. The experiment was conducted in the atmospheric boundary layer wind tunnel at the Niigata Institute of Technology in Japan. A cubic model with width 200 mm was located on the sand surface with depth 30 mm, and the erosion and deposition patterns on the sand surface were measured following the blowing of wind. Considerable wind erosion was observed near the windward corners of the cube, in contrast to small deposition in other areas. Primary CFD analysis of wind erosion was then conducted to reproduce the results of the experiment. The results confirmed that the various shapes of large erosion regions near the upwind corners of the cube were accurately reproduced by CFD, even when performing relatively simple modeling of sand transport. However, the erosion area in the prediction result was horizontally wider than that of the experiment. These differences are mainly the result of not considering that the horizontal movement of the sand particles relates to the angle of repose in the CFD simulation.