基于透平正向设计模式的液力透平数值仿真研究

Research on Numerical Simulation of Hydraulic Turbine Based on Turbine Forward Design Method

摘要: 为进行液力透平正向设计模式的成熟化应用探索，该文以某一型号两级液力透平参数为设计目标，利用国内自主研发的TurboTides软件进行透平正向设计及数值仿真。以该透平为对象，分别利用TurboTides与ANSYS CFX平台在不同流量工况下对透平内部流动进行数值计算，以初步验证国内自主研发平台在液力透平正向设计和CFD数值计算上的可靠性，针对多级液力透平内部气液两相流动进行了初步研究分析。结果表明：在主要运行工况下和误差允许范围内，TurboTides单流道周期性网格计算的精确性不亚于CFX的全流道计算结果，且其计算更加节省计算资源和时间，在工程设计中采用TurboTides进行液力透平设计及计算有较大优势。同时初步推测，该两级液力透平靠近出口工作级的低压区易发生工质汽化导致气液两相流动。多级液力透平内部低压区的工质汽化有可能是其气液两相流动发生的主要原因之一。

Abstract: In order to explore the mature application of forward design mode of hydraulic turbine, the pa-rameters of a two-stage hydraulic turbine were taken as the design objective, and the domestic independently developed software TurboTides was used to carry out forward design and numerical simulation of the turbine. Based on the turbine, the TurboTides and ANSYS CFX were used to perform numerical calculations on the internal flow of the turbine under different flow conditions to preliminarily verify the reliability of the domestic independent research and development platform in the hydraulic turbine forward design and numerical calculation. The gas-liquid two-phase flow in multi-stage hydraulic turbine was preliminarily studied. The results show that: under the main operating conditions and within the allowable error range, the accuracy of TurboTides single channel periodic grid calculation is no less than that of CFX full channel calculation, and its calculation saves more calculation resources and time, so it has great advantages in engineering design. At the same time, it is preliminarily speculated that the low pressure area of the two-stage hydraulic turbine working stage near the outlet is easy to have cavitation, resulting in two-phase flow of gas and liquid. The cavitation of the working fluid in the low-pressure area inside the multi-stage hydraulic turbine may be one of the main reasons for the occurrence of the gas-liquid two-phase flow.