轴流泵叶轮叶顶区空化特性试验分析

发布时间：2019-04-13 20:31

【摘要】：为了研究叶顶区空化特性,以某一模型轴流泵为研究对象,利用高速摄影试验,探讨不同叶片数下泵的水力性能和空化性能、不同流量下的叶顶泄漏涡轨迹、不同空化数下的叶顶空化形态以及叶顶区空化发展瞬态特性.试验结果表明,适当增加叶片数,泵的水力性能和空化性会更好;在小流量工况下,叶顶更易发生空化初生;随着流量的增大,叶顶泄漏涡轨迹与叶片吸力面的夹角逐渐减小,同时泄漏涡初生点逐渐向叶顶尾缘移动;在叶顶三角形云状空化尾缘产生云状空化涡,受到叶顶泄漏涡的卷吸,与叶顶泄漏涡涡带尾缘脱落的空化涡相互作用混合,沿着几乎垂直叶片的方向向相邻叶片的压力面移动,造成了流道的堵塞,降低了泵的水力性能.垂直云状空化涡堵塞流道,引起叶顶区流量减小,造成叶顶间隙空化减少以及与叶顶区相连的三角形云状空化的宽度减小.
[Abstract]:In order to study the cavitation characteristics of a model axial-flow pump, the hydraulic performance and cavitation performance of the pump under different vane numbers and the tip leakage vortex trajectory under different flow rates were investigated by high-speed photography experiments. The cavitation morphology of the leaf top and the transient characteristics of the cavitation development in the leaf top region under different cavitation numbers. The experimental results show that the hydraulic performance and cavitation of the pump are better when the number of vane is increased properly, and the cavitation is more likely to occur at the tip of the pump under the condition of small flow rate. With the increase of the flow rate, the angle between the tip leakage vortex trajectory and the suction surface of the blade decreases gradually, and the initial point of the leakage vortex moves to the tip trailing edge of the blade. A cloud-like cavitation vortex is generated at the tip of the triangular cloud-shaped cavitation trailing edge of the blade, which is entrapped by the tip leakage vortex and interacts with the cavitation vortex falling off the trailing edge of the tip leakage vortex band, and moves in the direction of the almost vertical blade towards the pressure surface of the adjacent blade. It causes the blockage of the flow channel and reduces the hydraulic performance of the pump. Vertical cloud-shaped cavitation vortex blocks the passage, resulting in a decrease in the flow rate at the top of the blade, a decrease in the clearance between the blades and a decrease in the width of the triangular cloud-like cavitation connected to the top of the blade.
【作者单位】：江苏大学流体机械工程技术研究中心;
【基金】：国家自然科学基金资助项目(51479083) 江苏省产学研前瞻性联合资助项目(BY2015064-08) 江苏省重点研发计划资助项目(BE2015001-3) 江苏省优势建设学科资助项目
【分类号】：TH312

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