离心泵输油粘度换算图的数学表达式

离心泵输送粘度大于水的石油产品或其它流体时，一般用输送水时的性能参数换算确定泵输送粘性流体时的性能。目前常采用前苏联国家石油机械研究设计院和美国水力学会的粘度换算图计算。根据两图各自采用的修正雷诺数，用修正雷诺数的常用对数作为自变量，把各换算系数看作雷诺数的函数，采用数理统计和回归方法做了公式化处理，，将换算系数拟合成与各修正雷诺数的数学表达式。两计算实例表明，该数学表达式计算的结果与查图的结果具有很好的一致性，可取代粘度换算图，满足计算机编程的需要，也可用于输油离心泵的选择和设计计算。

Mathematic expression for viscosity conversion chart of oil pumped by centrifugalpumps

When oil products or other fluids with viscosity larger than that of water, the pump's performance is usually conversed and determined by its performance parameters in pumping water. The viscosity conversion charts used by the former Soviet Union and the American Hydraulic Institute are often adopted for the calculation. According to the correctional Reynolds numbers, taking the common logarithm of the correctional Reynolds numbers as independent variable, and regarding the conversion factors as the functions of the Reynolds numbers, the conversion factors are fitted to the mathematic expressions for the correctional Reynolds numbers. Examples of calculation show that, the results calculated by the mathematic expressions accord with the results obtained from the conversion chart, therefore the expressions can be used instead of the viscosity conversion chart.