【摘要】 为研究叶片不同倾斜方式对液力缓速器制动力矩的影响,笔者采用了雷诺时均N-S方程、标准k-ε模型和SIMPLEC算法对液力缓速器内部流场进行了数值模拟,分析叶片前倾、后倾时液体流动的速度分布、压力分布和湍动能分布规律。以Rothalpy值的变化作为损失分析指标,定量比较叶片不同倾斜方式对液力缓速器制动力矩的影响,得出叶片前倾时缓速能力较大的原因是:液体在轴面流道内形成方向一致的涡旋,在动轮内受叶片的带动使速度增加,在动轮出口处速度达到最大,对定轮叶片形成冲击造成速度下降,液力损失显著;而流体在叶片后倾的流道内没有形成涡旋,在动轮与定轮的轴向交界面内液流交错进出,在界面内沿径向同时有液流的流入和流出,叶片后倾时流道内压力、速度和湍动能分布与叶片前倾时相比,分布范围明显降低,液力损失极小。更多还原

【Abstract】 By using the time-averaged N-S equation and the standard k-ε turbulence and the SIMPLE-C algorithm simultaneously,the internal characteristic of flow field was simulated.The calculated velocity,pressure and turbulent kinetic energy distribution of the turbulent flow in a hydraulic retarder were given.The method of loss analysis was proposed which changed the value of Rothalpy for comparing the retarder ability,and results show that the model with lean-front vane has the bigger impact because the fluid forms vortex in axial section,that is to say,the fluid speed is increased in a rotator driven by a blade which reach the biggest at exit and descend in a stator which causes hydraulic loss remarkably;while liquid in flow the field with lean-back vane could not form vortex,the fluid flow in and out simultaneously along radial direction in the interface,thus the distributed scope of pressure,speed and kinetic energy reduces obviously compared to the model with lean-front vane,so the liquid head is lost slightly.更多还原