液力涡轮内部的强约束流动与空化现象

发布时间：2018-03-02 08:32

本文关键词： 涡轮制动器流动结构瞬态过程空化力矩　出处：《工程热物理学报》2017年10期 　论文类型：期刊论文

【摘要】：为描述液力涡轮制动器内的流动特征及流动对制动器力矩性能的影响,采用计算流体动力学方法对制动器内的流动结构及空化现象进行了研究,获得了涡轮制动器瞬态启动和停止过程中转轮及挡板附近的流动参数分布,捕捉了制动器封闭腔体内的空化区位置和形态,求解了挡板上受到的流体载荷。结果表明,制动器腔体内存在着大尺度流动结构,其随着挡板与转轮之间的轴向距离增加而沿轴向发展;空化区出现在转轮叶片背面及根部附近,空化相体积份额随转轮转速增加而增大,但未对制动器的力矩系数造成明显影响;作用在挡板上的轴向流体作用力的合力方向始终指向转轮侧,该力的大小随转轮转速和叶轮与挡板间距增加而增加。
[Abstract]:In order to describe the flow characteristics in the hydraulic turbine brake and the effect of the flow on the torque performance of the brake, the flow structure and cavitation in the brake are studied by using computational fluid dynamics (CFD) method. The distribution of the flow parameters near the runner and the baffle during the transient start-up and stop of the turbine brake is obtained. The position and shape of the cavitation zone in the closed chamber of the brake are captured, and the fluid load on the baffle is solved. The results show that, There is a large scale flow structure in the brake cavity, which develops along the axial direction with the increase of the axial distance between the baffle and the runner, and the cavitation area appears near the back and the root of the runner blade, and the volume share of the cavitation phase increases with the increase of the rotating speed of the runner. However, the torque coefficient of the brake is not significantly affected, and the resultant direction of the axial fluid force acting on the baffle always points to the runner side, and the force increases with the increase of the speed of the runner and the distance between the impeller and the baffle.
【作者单位】：江苏大学能源与动力工程学院;
【基金】：国家自然科学基金项目资助(No.51676087) 江苏省六大人才高峰项目资助(No.2015-ZBZZ-018)
【分类号】：O35;TH13

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