关键词: 分流断面, 迭代初值, 迭代增值, 双方程牛顿法

Abstract: First, in this paper, the energy equation is described in a simple form. Then, according to basic method of hydrauliccalculation about branches of a channel and basic principle of extraction the root with Newton’smethod, the formulas ofinitial value and increment of Newton’s sucessive approximation(double equations)to calculate the folw dividing of branches of channel is established.It is clear that this method can speed up computation rate and improve accuracy of theresults by example. In addition, the difference between Newton’s method for double equations and usual Newton’s methodis analysed,and the geometric implication of Newton’s method for double equations is discussed,and the method of deter-mining section of flow dividing and flow together is also explained.

Key words: seetion of flow dividing, initial value of sucessive approximation, increment of sucessive approximation, New-ton’s method for double equations