基于水力学模型的引水隧洞糙率反推计算研究

摘要

传统方法是将引水隧洞内水流假定为恒定流状态进行糙率的反推计算，而未考虑引水隧洞内水流非恒定性，本文引入圣维南方程组，采用数学差分法求解方程，建立适合于引水隧洞的水力学模型，结合隧洞实测水位流量资料，反推引水隧洞的糙率。研究结果表明：建立的水力学模型可用于隧洞的糙率反推计算，计算结果合理且符合水工建筑物糙率计算规范要求。研究成果可供引水隧洞糙率推求参考。%In traditional method, water flow in diversion tunnel is assumed into constant flow state for roughness backstepping calculation.Unsteady feature of water flow in water diversion tunnel is not considered.In the paper,Saint Venant Equation is introduced.Mathematical difference method is adopted to solve the equation.Hydraulics model suitable for water diversion tunnel is established. Roughness of water diversion tunnel is backstepped according to actual measurement level flow data of the tunnel.Research results show that the established hydraulics model can be used for tunnel roughness backstepping calculation.Calculation result is reasonable and conforms to the requirements of hydraulic structure roughness calculation specification.Research results can be used as reference for calculating diversion tunnel roughness.