1) channel with trapezoidal section
梯形断面排水沟
2) longitudinal and transverse sections of ditches
排水沟断面
3) water surface profiles of trapezoid
梯形断面水面线
4) trapezoid section
梯形断面
1.
The traditional methods for computing critical water depth of open channel with trapezoid section (h k) are trial and error method, graphic method, approximate solution method and iteration method, whose shortcomings are rough precision, large computation amount and complex resolving problem.
目前计算梯形断面明渠临界水深hk的常用方法有试算法、图解法、近似公式法和迭代法 ,它们存在计算精度不高、求解复杂等缺点。
5) hydraulic best trapezoid section
水力最佳梯形断面
1.
A nondimensional parameter method for calculating hydraulic best trapezoid section is presented, by which a hydraulic best trapezoid section is rapidly obtained.
提出了水力最佳梯形断面的无量纲计算方法,运用此法可快速方便地计算满足要求的水力最佳横断面,提高了设计人员的工作效率。
6) land drain
地面排水沟
补充资料：梯形中位线定理
梯形的中位线平行于两底，并且等于两底和的一半
l=（a+b）÷2
s=l×h
说明：补充资料仅用于学习参考，请勿用于其它任何用途。
参考词条