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针对雨天行车轮胎所产生的动水压力易导致水损害和车辆打滑的问题,运用计算流体力学理论建立路表径流条件下的道路-轮胎有限元模型,采用k-ε模型解析紊流闭合方程,VOF模型解析两相流的水流自由表面流动,SIMPLE算法对模型计算域内有限体积中速度-压力的耦合进行离散化,计算了不同轮胎花纹深度、水膜厚度和行车速度下的动水压力,并预测了不同条件下车辆出现“水漂”的临界行车速度。计算结果表明:随着水膜厚度的增加,轮胎所受的动水压力持续增长;当水膜厚度小于花纹深度时,动水压力随车速增长缓慢,当水膜厚度大于花纹深度时,动水压力与车速近似为线性关系;对于小型轿车,路表水膜厚度为8mm时,车速为145km/h时可出现“水漂”现象,水膜厚度为12mm时,出现“水漂”的车速降低为133km/h。
Aiming at the problem that the hydrodynamic pressure generated by the driving tires on rainy day can easily lead to water damage and vehicle slipping, the finite element model of the road-tire under the condition of road surface runoff is established by computational fluid dynamics theory, the turbulence closed equation is solved by k-ε model, VOF model is used to analyze the free surface flow of two-phase flow. The SIMPLE algorithm is used to discretize the coupling of velocity and pressure in finite volume in the model calculation domain. The hydrodynamic pressure under different tire tread depth, water film thickness and driving speed is calculated. Predict the vehicle under different conditions “water ” critical speed. The calculated results show that the hydrodynamic pressure sustained by the tire increases with the increase of the water film thickness. When the thickness of the water film is less than the depth of the pattern, the hydrodynamic pressure increases slowly with the vehicle speed. When the water film thickness is greater than the depth of the pattern, Pressure and speed are approximate linear relationship; for small cars, road surface water film thickness of 8mm, the speed of 145km / h when there may be “water drift ” phenomenon, the water film thickness of 12mm, "The speed reduced to 133km / h.