泵汽蚀曲线的分段多项式拟合

Pump Cavitation Curve Partition Multinomial Fitting

由于泵汽蚀曲线的特殊性,曲线形状直接影响NPSH3的取值。取值不同,影响对泵性能的判断。汽蚀曲线绘制方法有传统的手工绘法、多项式拟合法、非线性拟合法、三次样条插值法等。在此基础上,探讨了水泵汽蚀曲线拟合的方法,为了提高拟合曲线的精度,提出了一种泵汽蚀曲线分段多项式拟合的方法。并将该方法与非线性拟合和全部数据多项式拟合进行了比较,用该方法拟合的曲线不但光滑而且求出的NPSH3值较小。该方法较适合于泵汽蚀性能曲线的拟合。

Pump cavitation due to the particularity of curve, the curve shape of a direct is impacted on NPSH3 values. Value is different affect pump performance judgments. Cavitation curve hays been drawing method of the traditional hand-drawn method, polynomial fitting, non-linear fitting, cubic spline interpolation method. On this basis, the pump cavitation curve fitting method is discussed, in order to improve the accuracy of curve fitting, pump cavitation presents a piecewise polynomial curve fitting method. And that the methods and non-linear fitting and pol- ynomial fitting all the data were compared with the curve fitting using this method is not only smooth but also calculate the value of the NPSH3 smaller. This method is more suitable for pump cavitation performance curve fitting.