变螺距诱导轮的设计计算

为了有效降低泵的必须汽蚀余量，泵的吸入口可加装前置变螺距诱导轮。但变螺距诱导轮的设计方法还在摸索阶段。本文从分析变螺距诱导轮螺距变化规律入手，以诱导轮入口无汽蚀，出口扬程满足离心叶轮进口能量要求为计算依据，推导了诱导轮基本结构参数的计算方法。按照该方法设计的诱导轮可获得良好的汽蚀性能。

Design Calculation on Variable-pitch Inducers

Variable-pitch inducers can be fixed before impellers to lower the NPSHr of pumps efficiently. But their design method is still in groping stage. Starting with analyzing the variation regularities of pitch for variable-pitch inducers, considered that no cavitation in its inlet and the head could satisfy centrifugal impeller's intake energy, the computational method of the basic-structure parameters of an inducer has been deduced. Moreover, satisfactory cavitation performances were achieved by using the proposed method to design the variable-pitch inducer.