Abstract: The paper which made use of wedge angle of momentum caculated hydroplaning critical velocity in both cases which consists of small wedge angle( ＜ 0． 4°) and larger wedge angle． Analysis of the relationship between wheel pressure，water film thickness and hydroplaning critical velocity with the exam of cars，medium cars and trucks． The results showed that: no matter small or large wedge angle，water skiing and wheel speed directly proportional to internal pressure; wedge angle is larger and the wheel pressure is constant，water-skiing and water film thickness is inversely proportional to the speed． Verifying hydroplaning critical velocity according to NASA skilling speed equation and the result show that its reliability to meet the requirements．

Key words: water-skiing, water film, hydroplaning critical velocity, hydrodynamic pressure

摘要： 利用动量定理，分别计算楔角较小( 楔角小于0． 4°) 和楔角较大两种情况下滑水速度值。以小轿车、中型汽车 和载重车为例分析车轮内压、水膜厚度与滑水速度的关系。结果表明: 不论楔角较小或者较大，滑水速度与车轮内 压成正比; 楔角较大且车轮内压一定时，滑水速度与水膜厚度成反比。通过NASA 滑水速度方程，对理论计算的滑 水速度值进行验证，得出它的可靠性满足要求。

关键词: 滑水, 水膜厚度, 临界滑水速度, 动水压力