正三角形组合喷灌均匀度计算方法!

Calculation Methods for Irrigation Uniformity with Sprinklers Spaced in Regular Triangle

喷灌均匀度是衡量喷头水力性能和喷灌质量的重要指标,为研究雨量筒取样间距、计算网格点间距以及插值方法对喷灌均匀度计算结果的影响规律,利用雨量筒径向间隔为1 m和2 m的Nelson R33型喷头无风喷洒试验数据,取1 m和0.5 m的计算网格点间距,采用线性插值、立方插值、三次样条插值的两次插值法、距离插值法和平面插值法计算了克里斯琴森均匀度。结果表明,采样间隔1 m比2 m计算出的均匀度小1.3～3.4个百分点;计算网格点间距越小,喷头组合均匀度越大,但相差都小于1.2个百分点。采用线性插值、立方插值、三次样条插值的两次插值法和距离插值法,喷灌组合均匀度计算结果非常接近,但平面插值法计算结果的差异较大。均匀度影响因素正交试验的方差分析结果表明,雨量筒采样间距、计算网格点间距、插值方法对均匀度的影响依次降低。

Uniformity coefficient of sprinkler irrigation is an important indicator for measuring hydraulic performance and irrigation quality of sprinkle irrigation system. In order to investigate the influence of the catch-can space, grid space and interpolation methods on the christiansen uniformity （Cu）, Cu was computed by linear interpolation, cubic interpolation, cubic spline twice interpolation, inverse distance weighting method and plane interpolation method with 1 m and 2 m sampling spaces, and 1 m and 0.5 m grid spaces. The experiment was preceded indoor with no wind for the single sprinkler Nelson R33. The data here used to compute the Cu were measured in catch cans along one radial leg from the sprinkler position. The results showed that C~ computed from 2 m space catch-can data were less than that from 1 m space catch-can data by 1.3% -3.4%. Smaller the grid space was, greater the Cu was, with deviations all less than 1.2%. The C calculation results by linear interpolation, cubic interpolation, cubic spline twice interpolation and inverse distance weighting method were very close to each other. However, Cu showed great difference when using the plane interpolation method with the other methods. The orthogonal test of variance analysis method was used to analyze the factors which influence the result of the Ca. The results showed that the influence of catch-can space, grid space and interpolation method on C~ was less and less in turn.