【作者】 卢秀泉；

【导师】 马文星；

【作者基本信息】 吉林大学 ， 机械设计及理论， 2012， 博士

【摘要】 随着我国的经济发展，各个工业领域所用设备功率增加非常快，尤其大型泵与风机用量不断增加，迫切需要大功率调速节能产品。大功率调速型液力偶合器作为理想的节能调速产品受到广泛的重视和应用。调速型液力偶合器在输入转速一定时，通过改变工作腔内的充液率来满足负载的要求，在与其它工业设备匹配传动时，具有平稳启动、无极调速、减缓设备冲击扭振、改善传动品质等诸多优点，而且应用调速型液力偶合器传动后节能效果十分显著，具有工作机功率越大节能效果越好的特点。我国的液力生产厂家目前还不具备独立研发大功率调速型液力偶合器产品的能力，针对我国大功率调速型液力偶合器产品设计中所面临的一些关键技术问题，本文结合国家高技术研究发展计划（863计划）专题课题“大型泵与风机液力调速节能关键技术研究”（2007AA05Z256），对液力偶合器的流固耦合问题和振动特性问题做了较为系统深入的研究。系统介绍了流固耦合理论及数值计算方法。针对液力偶合器工作时流场特点介绍了旋转坐标系下的流动控制方程和叶轮结构动力学方程。重点介绍了流固耦合问题两种数值求解方法：整体求解法和分域求解法，同时对数值计算中流固耦合界面的描述方法、信息传递形式及控制条件做了说明。基于流固耦合数值计算理论及算法，选择YOCQZ465型调速型液力偶合器为研究对象，对其工作中的流固耦合问题进行了数值模拟。首先采用单向流固耦合数值模拟方法，对液力偶合器叶轮在不同充液率、不同工况下的变形和应力状态进行分析，对叶轮的强度进行校核。在此基础上采用双向流固耦合数值模拟的方法，应用稳态和瞬态两种算法，对制动工况下偶合器的流场特性和涡轮叶片结构动力学特性进行研究。基于势流体理论，采用流固耦合的模态求解方法对液力偶合器叶轮和叶片在工作流体介质中的模态进行了数值模拟。采用考虑预应力的模态分析方法，对不同转速比和充液率工况下叶轮的振动特性进行了分析。得到叶轮在实际工作中可能出现的共振频率，并找出工作中叶轮结构上振动的敏感区域。对泵轮的旋转强度和液力偶合器传动装置在实际工作中的振动情况进行实验研究。首先采用遥测的方法，对泵轮在不同高速旋转工况下的强度进行测试。将各个转速工况下测点处应变的有效值与相应转速工况下有限元数值模拟结果相对比，验证遥测实验结果的可靠性。对实际工作中的液力偶合器传动装置进行振动测试。测试时在传动装置箱体上选取十个典型位置安放测点，将采集到的每个测点三个方向上的加速度振动信号进行时域和频域分析，从而对工作中液力偶合器传动装置箱体上各个位置的振动情况进行定性和定量的判断。综上可述，本文采用流固耦合数值模拟和实验研究的方法，对液力偶合器的流固耦合问题和振动特性做了较为系统的研究。本文的工作为液力偶合器在流固耦合作用下的流场特性预测、叶轮结构动力学计算及结构振动特性预测提供依据，对大功率液力偶合器产品的设计具有一定的指导意义。更多还原

【Abstract】 With the economy rapid development, the industry devices with large power areincreasing demanded, especially for the large-scale pumps and fans with variable speed andenergy-saving. Owning to the advantages of large power, variable speed and energy-saving,the hydrodynamic coupling is widely used and has been more and more concerned. For acertain input speed, the output power of the hydrodynamic coupling can be changed bychanging the filling rate of the working chamber. Therefore, when connected to otherdevices, the hydrodynamic couplings can achieve the smooth start and stepless speedadjustment, reduce the impulse and vibration and improve the transmission quality.Moreover, the energy saving effect of the hydrodynamic coupling is prominent, and thehigher power output has the better energy saving effect. However, there is a certain distanceto independently development the domestic hydrodynamic coupling. Supported by theNational863High-tech Project “Key Technological Research on Hydrodynamic VariableSpeed and Saving Energy of Large-scale Pump and Fan,” this paper systematically studiesthe key techniques of the hydrodynamic coupling in the aspects of the fluid-structureinteraction and vibration characteristic, specific details are as follows:The theory and numerical computation methods related to fluid-structure interaction areintroduced. Aiming at the flow field characteristics of the hydrodynamic coupling, the fluidcontrol equation and impeller structural dynamic equation are deduced under the rotatingreference frame. Two numerical computation methods of integral solution method andsub-region solution method are specially introduced, and the description method,information transfer form and control conditions are declared for the fluid-structureinteraction surface in the numerical computation.Based on the numerical computation algorithm of the fluid-structure interaction andtaken the variable speed hydrodynamic coupling YOCQZ465as research subject, thefluid-structure interaction phenomenon is numerical simulated. Firstly, with the numerical computation method of the unidirectional fluid-structure interaction, the strain and stress ofthe hydrodynamic coupling impeller are analyzed, and the impeller strength is checked. Andthen with the numerical computation method of the bidirectional fluid-structure interaction,the flow field characteristic and the turbine blade dynamic feature are studied in thecondition of the braking working, which are analyzed both in the steady state and transientstate.Based on the potential fluid theory, the fluid-structure interaction of the hydrodynamiccoupling impeller and blade is numerical simulated with the modal solution method. Withthe modal solution method taking the pre-stress into consideration, the vibrationcharacteristics of the impeller are studied under different velocity ratio and different fillingrates, the possible resonant frequencies are obtained for impeller practical working, and thesensitive frequencies areas of the impeller vibration are also found.In order to validate the numerical simulation results, experiments are carried out to testthe strength of pump wheel and the vibration characteristic of the hydrodynamic couplingdriving device in its practical working. With the remote sensing method, the strength of thepump wheel are tested in different rotating speed. Compare the strain effective value of themeasuring points with the corresponding simulation results and validate the reliability of theremote sensing experimental result. In order to test the vibration characteristic of thehydrodynamic coupling driving device, ten measuring points are put in ten typical locationson the hydrodynamic coupling driving device, and the tested vibration signal of theacceleration in x, y, z direction are analyzed in time domain and frequency domain, which isused to estimate the vibration of the hydrodynamic coupling driving device in qualitative andquantitative.To sum up, according to numerical simulation and experiment validation, thefluid-structure interaction and vibration characteristic of the hydrodynamic coupling aresystematically studied. The study can be used to predict the flow field characteristic,calculate impeller structural dynamic and estimate the structure vibration feature, which hascertain significance for guiding the large power hydrodynamic coupling design.更多还原