A combined approach of inverse method and direct flow analysis is presented for the hydrodynamic design of gas-liquid two-phase flow rotodynamic pump impeller. The geometry of impeller blades is designed for a specified velocity torque distribution by treating the two-phase mixture as a homogeneous fluid under the design condition. The three-dimensional flow in the designed impeller is verified by direct turbulent flow analysis, and the design specification is further modified to optimize the flow distribution. A helical axial pump of high specific speed has been developed. To obtain a favorable pressure distribution the impeller blade was back-loaded at the hub side compared to the tip side. Experimental results demonstrate that the designed pump works in a wide flow rate range until the gas volume fraction increases to over 50% and its optimum hydraulic efficiency reaches to 44.0% when the gas volume fraction of two-phase flow is about 15.6%. The validity of design computation has been proved.

The performance characteristics of an axial-flow pump with tandem blades are studied based on the numerical computations. The arrangement of the pump impellers is established through the analysis of velocity triangles. With the commercial computational fluid dynamics (CFD) software NUMECA, the turbulent flow in the tandem axial-flow pump is simulated in various flow conditions. The detail flow structure in the leading edge region of the rear impeller is described, and the influence of the deflection angle of the rear blade on the head performance is studied. According to the simulation, the performance comparison is made between the tandem axial-flow pump and the conventional two-stage axial-flow pump with a uniform impeller size. Results of the study indicate that the tandem axial-flow pump can work in a wider range with high efficiency.

通过二次开发方法在CFX软件中引入滤波器湍流模型（FBM）。分别应用FBM模型和标准k−ε模型对Hydronautics翼形的超空化流动进行了数值模拟，并结合水洞实验结果从空泡形态和流场结构两方面对两种湍流模型的计算结果进行对比分析。结果表明，相对标准k−ε模型，FBM模型对空泡形态和空泡尺度的模拟更符合实际。FBM模型可以捕捉超空化流动中较大尺度的涡团结构，并能更清晰的模拟出空化区尾部涡团交替脱落的非定常细节。同时，FBM模型对超空化流动中反向射流现象的模拟更为敏感。

As the key equipment in the gas-liquid multiphase mixed transportation technique, the multiphase rotodynamic pump has been the focus of people’s concern. But the design of such a pump is formidable and challenging because it should simultaneously have the characteristics of a pump and a compressor. In this paper, based on the Navier-Stokes equations and the k–ε turbulent model, the 3-D turbulent flow in a multiphase rotodynamic pump impeller has been simulated numerically by using the SIMPLEC algorithm in body-fitted coordinates with the staggered grid system. The results show that the vortex region mainly exists near the tip of the impeller and the centrifugal force is an important factor to affect the formation of vortex flow that will lead to the hydraulic loss and efficiency decrease.

基于双流体模型建立针对叶片泵内气液两相三维湍流流动的数学模型和数值计算方法。相间作用力考虑了阻力和附加质量力，湍流模型考虑了因相含量脉动引起的附加源项，在SIMPLEC算法基础上提出了一种气液两相流的压力修正算法。运用所建模型计算了叶片式气液混输泵在进口含气率分别为5%，15%，25%的系列工况下叶轮的内部两相流场，并作了扬程特性预测。与实验结果的对比表明，所提出的流动模型是可靠的，并具有较宽的进口含气率适用范围。