中文摘要：

在矩形扩散渠槽水跃的水面按线性变化和侧墙反力按梯形计算假设的基础上，根据动量原理，推导了矩形扩散渠槽的水跃方程．通过级数展开处理，获得了矩形扩散渠槽的水跃方程的近似解．近似解的计算结果和实验值～致．将近似解应用于矩形明渠水跃水力计算，在稳定水跃范围内，近似解与经典的矩形明渠水跃的理论解析解的最大相对误差为6．67％．说明矩形扩散渠槽的水跃方程的近似解可以应用到工程计算．

英文摘要：

Based on the assumptions of the linear variation of the water surface profile and the trapezoidal pressure distribu- tion on the side wall in the hydraulic jump in a rectangular expanding channel, an equation of the hydraulic jump in a rec- tangular expanding channel is derived by using the momentum principle in this paper. An approximation solution of the hydraulic jump equation is obtained by applying the analysis of series expansion. The calculated values of the solution of approximation agree with the experimental data. By applying the approximation solution to the hydraulic jump in a rectan- gular open channel, the maximum error of the approximation solution relative to the classically theoretical solution in a rectangular open channel is 6.67% in the range of a steady jump. The results have shown that the approximation solution of the hydraulic jump equation can be used to compute the engineering problem.