旋壳转速对腔内液体流动特性的效应  

Effect of rotational speed of spiral shell on liquid flow characteristics in cavity

作　　者：刘在伦[1,2] 顾生富 赵伟国 吕佩涛[1] 曾继来 LIU Zailun;GU Shengfu;ZHAO Weiguo;LYU Peitao;ZENG Jilai(College of Energy and Power Engineering,Lanzhou University of Technology,Lanzhou,Gansu 730050,China;Key Laboratory of Fluid Machinery and Systems,Gansu Province,Lanzhou,Gansu 730050,China)

机构地区：[1]兰州理工大学能源与动力工程学院,甘肃兰州730050 [2]甘肃省流体机械及系统重点实验室,甘肃兰州730050

出　　处：《排灌机械工程学报》2023年第2期124-131,共8页Journal of Drainage and Irrigation Machinery Engineering

基　　金：国家自然科学基金资助项目(52169018)。

摘　　要：为研究旋壳转速对腔内液体流动特性的影响,以试验旋喷泵为研究对象,在高度验证叶轮与旋壳同步旋转试验与模拟结果准确性的基础上,对叶轮转速相同、旋壳转速不同的5个模型采用RNG k-ε湍流模型进行数值计算,分析腔内液体流动特性的变化情况,研究泵的性能.结果表明:旋壳转速增大,液体圆周速度和旋转系数均增大,圆周速度曲线沿径向逐渐形成同心圆,腔内液体做非刚性旋转.腔内液体径向压力梯度增大,压力低于624 kPa时,旋壳转速越高,压力越小;压力高于624 kPa时,旋壳转速越高,压力越大.集流管迎流区涡分布在进口附近,尾迹区涡集中在扩散段结尾处,整体呈增大趋势.旋壳转速增大,泵的扬程升高,但效率降低,通过改变集流管进口直径发现集流管并非效率降低的主要原因,而是由圆盘摩擦损失的增大导致的,圆盘摩擦损失随旋壳转速增加呈3次幂函数式增大,文中最优进口直径为13 mm.In order to study the influence of the rotational speed of the spiral shell on the liquid flow characteristics in the cavity, the experimental roto-jet pump was used as the research object. On the basis of verifying the accuracy of the synchronous rotation experiment and simulation results of the impeller and the spiral shell, the RNG k-ε turbulence model was used for numerical calculation for five models with the same impeller speed and different spiral shell speeds to analyze the change of the fluid flow characteristics in the cavity and study the performance of the pump. The results show that as the rotational speed of the spiral shell increases, both the peripheral velocity and the rotation coefficient of the liquid increase, the peripheral velocity curve gradually forms concentric circles along the radial direction, and the liquid in the cavity rotates non-rigidly. The radial pressure gradient of the fluid in the cavity increases when the pressure is lower than 624 kPa, whereby a higher rotational, speed results in a lower pressure. When the pressure is higher than 624 kPa, a higher rotational speed results in a higher pressure. The vortices in the upstream region of the collector are distributed near the inlet, and the vortices in the wake region are concentrated at the end of the diffuser section, resulting in an overall increasing trend. As the speed of the spiral shell increases, the head of the pump increases, but the efficiency decreases. By changing the diameter of the inlet of the collecting pipe, it is found that the collecting pipe is not the main reason for the decrease in efficiency, but the increase of the friction loss of the disc causes the decrease. The loss increases with the increase of the rotational speed of the spiral shell in a 3rd power function, and the optimal inlet diameter that used in this paper is 13 mm.

关 键 词：旋喷泵 旋壳转速 流动特性 效率 数值计算 

分 类 号：TH311[机械工程—机械制造及自动化]