How do dunes along a desert urban motorway affect the driving safety of sedans? Evidences from long- and short-term monitoring and IDDES

Urban on the edge of deserts usually build motorways in desert areas to fully develop its tourism resources. However, due to the long-term transport effect of wind-sand flow (WSL), the driving safety of sedans might be affected by the erratic dunes next to the desert motorway. Based on this, this study aims to give an idea of how dunes next to desert urban motorways affect the driving safety of sedans. Firstly, the movement law of WSL in desert areas is revealed based on the combination of long- and short-term monitoring methods. After determining the period of strong wind through long-term monitoring, short-term monitoring can be more effective in revealing the movement law of the WSL and the aerodynamic performance of the sedan under the effect of WSL. Afterward, a three-dimensional refined Computational Fluid Dynamics (CFD) dynamic mesh numerical model of WSL-dune-embankment-sedan-air was established based on the mosaic mesh technology. The aerodynamic impact and erosion effects of the WSL on the sedan were investigated. The main results are as follows: 1. Dunes cause varying WSL, with wind speed decreasing to 19–26% on the leeward side and increasing to about 1.35 times at the end. 2. The windward side and front of the sedan experience continuous sand impact, severely eroding the body surface, and posing safety risks. The main contributions of the present study are expected to proposed a cheap simulation scheme based on IDDES (Improved Delayed Detached Eddy Simulation)-DPM (Discrete Phase Model) for WSL-dune-sedan-embankment.