单喷头水量分布函数拟合研究

Fitting research on water distribution function of single sprinkler

喷灌系统的均匀系数通常由单喷头的水量分布数据通过叠加法计算得到。为给均匀度计算提供更精准可靠的水量叠加基础,本文采用量筒径向布置法测量了6个不同型号单喷头的水量分布数据,根据各个喷头水量分布特点分别采用连续多项式函数和分段函数来拟合单喷头水量分布。结果表明:单喷头水量分布根据总体形态可分为单峰、双峰、下降式和平缓式等;GJYA-2和FY RB-471喷头的水量分布呈平缓单一的单峰或平缓下降式,采用连续多项式函数拟合即可达到拟合效果,而中原12y喷头的水量分布呈比较复杂的双峰,需采用分段拟合来提高拟合精度和效果;采用分段函数拟合时函数式次数较低精度更高,但分段函数用于组合均匀度叠加计算时比采用连续函数叠加更为复杂。

The uniformity coefficient of sprinkler irrigation system is usually calculated by the superposition method based on the water distribution data of a single sprinkler.In order to provide more accurate and reliable water quantity superposition foundation for uniformity calculation, the radial arrangement method of measuring cylinder was adopted in this paper to measure the water quantity distribution data of 6 different types of single sprinkler.According to the water quantity distribution characteristics of each sprinkler, continuous polynomial function and piecewise function were used to fit the water quantity distribution of single sprinkler.The results show that:The water distribution of single sprinkler can be divided into single peak, double peak, descending and gentle type according to the overall shape;The water distribution of GJYA-2 and FY RB-471 sprinkler presents a single peak or gentle decline, and the fitting effect can be achieved by using continuous polynomial function fitting, while the water distribution of zhongyuan12y sprinkler presents a relatively complex double peak, so piecewise fitting is needed to improve the fitting accuracy and effect;In the case of piecewise function fitting, the degree of function expression is lower and the accuracy is higher, but the calculation of the combined uniformity superposition of two piecewise functions is more complex than that of continuous function superposition.