论文部分内容阅读
天然河道的洪水波运动,可用著名的圣维南方程组来表示,当无旁侧入流时,其形式为A/t+Q/L=0 (1)H/L=1/g·v/t+v/g·v/L+Q~2/R~2 (2)式中:A——过水断面面积;t——时间;Q——断面平均流量;L——距离;g——重力加速度;R——流量模数;v——断面平均流速;H——水位。圣维南方程组的水力学解法以瞬态法和特征线法为代表,可绘出两断面间的水面曲线,但计算工作十分繁琐,且要有详尽的河道地形资料。水文学者所需要的是由上断面的入流推算下断面出流,而两断面间的水文情势是无关紧要的。因此在忽略摩阻项和惯性项之后,以
The wave motion of a natural river can be expressed by the famous Saint-Venant equation. When there is no side inflow, its form is A / t + Q / L = 0 (1) H / L = 1 / g · v / Where: A - the cross-sectional area of the water; t - time; Q - the average flow rate of the section; L - distance; g- - Gravity acceleration; R - Flow modulus; v - Average velocity of section; H - Water level. Hydrodynamic solution of Shengweinan equation group is represented by transient method and feature line method, and the water surface curve between two sections can be drawn. However, the calculation work is very complicated, and detailed information of river terrain is required. What hydrologists need is to infer the outflow under the inflow of the upper section, and the hydrological situation between the two sections is irrelevant. So after ignoring the friction term and the inertia term,