Authors

Abstract

Wind-blown sand erosion threatens agricultural-vehicle lamp covers, yet the effects of wind speed and yaw angle have not been sufficiently quantified. A one-way coupled Eulerian–Lagrangian CFD model of a full-scale isolated polycarbonate (PC) lamp cover was combined with gas-jet erosion tests on flat PC specimens for trend-level comparison. Wind speeds of 10–30 m/s and yaw angles of −30° to 30° were investigated, with erosion predicted using the Oka model. Erosion was concentrated near the windward leading edge and downstream surface, whereas the maximum pressure remained closer to the stagnation region. The mean and maximum erosion rates followed power-law relationships with exponents of 2.70 and 2.31, respectively. From −30° to 30°, the mean erosion rate increased by 28.3%, 57.0%, and 13.9% at 10, 20, and 30 m/s, respectively. At 30 m/s, the maximum erosion rate increased by 55.8% from 0° to 30°. At 20 m/s, the erosion concentration factors were 13.31, 5.45, and 9.54 at −30°, 0°, and 30°, respectively. Over the same yaw-angle range, the experimental mass loss increased by 212.5%, 115.4%, and 88.9%, while the surface roughness increased by 23.9%, 18.9%, and 20.1%. After normalization, the numerical and experimental indicators exhibited consistent yaw-angle-dependent trends (R² = 0.9481, RMSE = 0.0822, MAE = 0.0671). Within the investigated conditions, the model successfully captured the relative erosion trends, and the combined indicators supported the assessment of localized erosion risk.

Abstract in Chinese

风沙冲蚀对农用车辆灯罩的服役性能构成威胁，但风速与偏航角对其冲蚀特性的影响尚未得到充分量化。本文建立全尺寸孤立灯罩的单向耦合欧拉–拉格朗日CFD模型，并结合平板聚碳酸酯试样气固射流冲蚀试验进行趋势对比。研究考虑10–30 m/s的风速和−30°–30°的偏航角，并采用Oka模型预测冲蚀。结果表明，冲蚀主要集中于迎风前缘及其下游表面，而压力峰值更接近滞止区域。平均冲蚀率和最大冲蚀率均与风速呈幂律关系，其指数分别为2.70和2.31。偏航角由−30°增至30°时，10、20和30 m/s下的平均冲蚀率分别增加28.3%、57.0%和13.9%。在30 m/s下，最大冲蚀率由0°至30°增加55.8%。在20 m/s下，−30°、0°和30°对应的冲蚀集中系数分别为13.31、5.45和9.54。在相同偏航角范围内，试验质量损失分别增加212.5%、115.4%和88.9%，表面粗糙度分别增加23.9%、18.9%和20.1%。归一化后的数值与试验指标均呈现出一致的偏航角依赖变化规律。（R² = 0.9481，RMSE = 0.0822，MAE = 0.0671）。在本文研究条件下，该模型能够反映相对冲蚀变化趋势，综合指标可为局部冲蚀风险评估提供依据。