缝隙引流叶片对离心泵振动影响机理研究

Vibration is the most common problem in the operation of centrifugal pump unit, which directly affects the safe and reliable operation of the unit. It is still a difficult problem to accurately calculate the fluid-induced vibration and study the influence mechanism of flow on the vibration of the centrifugal pump. The key problems such as the establishment of the precise calculation method for the fluid-induced vibration and the relationship between the unsteady flow and the vibration in the pump have not been solved so far. Based on the theoretical analysis, numerical calculation and physical experiment methods, the internal mapping relationship between the gap-drainage blades and the characteristics of vibration induced by unsteady flow in centrifugal pump would be carried out systematically and thoroughly, and the calculation method of fluid-induced vibration would be constructed to achieve the accurate numerical simulation of the unsteady fluid-induced vibration in centrifugal pump, and the mechanism of internal flow and fluid-induced vibration in centrifugal pump would be studied to establish the quantitative relationship between the geometrical parameters of gap-drainage blades and the characteristics of the hydraulic performance and fluid-induced vibration of centrifugal pump, which can provide theoretical and experimental foundation for the design of low-vibration centrifugal pump.

振动是离心泵机组运行中最为常见的问题，直接影响机组的安全可靠运行。但目前，准确计算离心泵流体激振和研究泵内流动对振动的影响机理依旧是难题。其中，离心泵非定常流体激振精确计算方法的确立及泵内非定常流动与振动之间映射关系的建立等关键问题还未解决。本项目拟结合理论分析、数值计算和物理实验等方法对缝隙引流叶片与离心泵内部非定常流体激振特性之间的内在映射关系开展深入研究，确立离心泵流体激振计算方法，进行离心泵内非定常流体激振计算，研究离心泵流体激振响应特性的内在机理，建立缝隙引流叶片几何参数与离心泵水力性能参数、流体激振响应特性之间的定量关系，为设计低振动离心泵提供有力的理论和实验支撑。

现代工业的发展对离心泵提出越来越高的要求，不仅要求离心泵高效区宽广、抗空化能力强，还要求有良好的动态特性，以保证离心泵运行地稳定性。振动是离心泵机组运行中最为常见的问题，直接影响机组的安全可靠运行。但目前，准确计算离心泵流体激振、研究泵内流动对振动的影响机理以及对离心泵水力诱振的控制依旧是难题。本项目结合数值和实验方法对离心泵内部流场测量的概化模型、单级离心泵模型和复杂结构离心泵模型的内部非稳态流动及动态特性展开研究。从离心泵内流场特点出发，为获取离心泵内部丰富的流动结构并同时考虑到离心泵叶轮旋转和流线弯曲对离心泵内部复杂流动的影响，以及离心泵旋转空化问题，构建了适合于离心泵内部非定常复杂流动和空化流动的数值计算方法。并从湍流模式和结构动力学理论出发，构建基于全流场流体激振力的转子系统运动方程。在此基础上，对转子系统干态和湿态下的固有特性、特征频率等进行分析。然后通过综合考虑离心泵内部流动特性、转子系统动力特性确定最佳的离心泵转系结构。采用流固耦合方法对复杂结构离心泵内部非定常流体激振进行求解，通过实验数据验证该方法的有效性。在此基础上，结合数据分析方法和实验手段，深入开展利用缝隙引流叶片抑制离心泵振动的机理研究。通过分析不同流量和不同空化数下缝隙引流叶片结构对离心泵内部非稳态流动的调节作用和动态特性的改善机理，获取离心泵流体激振响应特性的内在机理，建立缝隙引流叶片的几何参数与离心泵水力性能参数、流体激振响应特性之间的定量关系。该流动控制方法表现出的显著效果，提示我们可以从离心泵内部流场特性和含能分布出发，发展合理的流动控制手段，使其更有利于离心泵水力性能和动态特性的改善。并且为发展水力性能高、抗空化性能强和动态特性优良的离心泵或其他流体机械的设计提供理论依据和新的思路。