针对喷水推进泵在小流量工况下驼峰区流动失稳问题，在设计工况为Qdes，临界工况为0.75Qdes，深度失速工况为0.5Qdes下，在转速范围为450rpm-650rpm（此处转速仅适用于模拟与试验对比），流量范围为0.4Qdes-1.25Qdes中，采用计算流体力学方法对系统内部流动特性进行数值解析，着重研究了临界失速及深度失速工况下的流动失稳抑制机理，并提出基于机匣轴向开槽的流动控制技术。通过研究发现：流动失稳特征表明，临界失速与深度失速工况下均呈现典型驼峰特性，导致流场品质恶化和效率显著下降；端壁开槽结构展现出显著流动控制效果，临界失速工况扬程提升9.7%，深度失速工况提升幅度达31.3%，成功消除驼峰现象。该改进方案在设计工况下导致效率略微下降1.6%；轴向槽改变了失速工况叶顶间隙泄漏流运动轨迹，将径向泄漏流转化为轴向流动，减小了叶轮进口速度环量，增大进口轴向速度，增强了叶轮的做功能力，提高了推进泵的扬程；受轴向槽数周期性扰动和槽道泄漏流与主流的非定常掺混影响，端壁开槽在15倍和30倍轴频处诱导能量峰值。本研究成果创新型在为喷水推进泵的失速预警和流动主动控制提供了理论依据，所提出的轴向开槽方案在工程应用中展现出良好的失速抑制潜力。

In addressing the issue of flow instability in a jet propulsion pump under low flow conditions, with the design flow rate set at Qdes, the critical condition at 0.75Qdes, and deep stall conditions at 0.5Qdes, a study was conducted within a rotational speed range of 450 rpm to 650 rpm (this speed is applicable only for simulation and experimental comparison) and a flow rate range from 0.4Qdes to 1.25Qdes. Utilizing computational fluid dynamics methods, a numerical analysis of the internal flow characteristics of the system was performed, focusing particularly on the flow instability suppression mechanisms under critical stall and deep stall conditions, and a flow control technology based on axial grooves in the casing was proposed. Through the study, it is found that: the flow instability characteristics show that the critical stall and deep stall conditions show typical hump characteristics, leading to the deterioration of the flow quality and a significant decline in efficiency; the end-wall groove structure shows significant flow control effect, the critical stall conditions head increase by 9.7%, and the depth of the stall conditions by 31.3%, successfully eliminating the phenomenon of hump. It is worth noting that the improvement programme led to a slight decrease in efficiency of 1.6% under the design conditions; axial groove changed the stall condition leaf top clearance leakage flow trajectory, the radial leakage flow into axial flow, reducing the impeller inlet velocity ring volume, increasing the inlet axial velocity, enhancing the impeller's ability to do work, and improving the head of the propeller pump; End-wall slotting induces energy peaks at 15 and 30 times the axial frequency, influenced by the periodic perturbation of the axial slot number and the non-constant mixing of the slot leakage flow with the main flow. The innovative results of this study provide a theoretical basis for the stall warning and active flow control of water jet propulsion pumps. The proposed axial slotting scheme demonstrates a strong potential for stall suppression in engineering applications.

国家自然科学基金项目（面上项目，重点项目，重大项目）