一种双吸式血液泵水力设计

Hydraulic design of a double suction blood pump

为了更好地满足体外循环装置和人工心脏的运行要求,该文采用RANS方法和SSTk-ω湍流模型对一种双吸式血液泵进行了三维定常湍流计算;在详细分析血液泵内部流动特征的基础上,对泵的水力部件如叶轮及压水室进行了设计优化,并探讨了各种设计对血液泵主要运行参数的影响。结果表明:压水室隔舌附近的流道容易出现较大的局部壁面剪切应力,是泵内血细胞容易受到损伤的危险区域;适当增大压水室断面面积有利于提高泵的水力效率;选择较大的叶片出口安放角时血液泵可获得较高的扬程,但采用径向叶片叶轮(出口叶片安放角为90°)时须设法控制流动扩散及其对泵性能的影响;所设计叶轮的平均壁面剪切应力为20～26 Pa,小于损伤血细胞的临界值。

The flow in pumps for open-heart and artificial heart units must be carefully optimized for the blood flow.The steady state three-dimensional turbulent flow inside a double suction blood pump was analyzed by solving the RANS equations with the SST k-ω turbulence model.The flow features in the blood pump were analyzed to optimize the design of the hydraulic components including the impeller and volute casing and the effects of various designs on the pump operating.The flow passage near the casing tongue has larger local wall shear stresses that may damage the blood cells,damage in the pump.The pump hydraulic efficiency can be improved by increasing the volute casing section area and a larger impeller vane exit angle will increase the pump head.Flow separation and its effect on pump performance can be controlled by a radial bladed impeller with a vane exit angle of 90°.The wall shear stresses for all designs were 20～26 Pa,less than the critical value for blood cell damage.