小型水库削峰能力模拟.pptx

小型水库削峰能力模拟 Simulate the Peak Flow Reduction of Small Reservoir 小型水库削峰能力模拟 问题或危机 专业知识+模型 模拟结果及解决方案 2012.01卫片 2014.04卫片 1.面临的问题与危机 Argued about the Influence of Brown Bridge Dam on Downstream Government’s View Downstream Villagers’ View Brown Bridge Dam 是否对下游村民造成影响？ 客观存在的Brown Bridge Dam 科学的方法 FLOOD ROUTING Computational Fluid Dynamics Hydrology Mathematical Model Hydraulics 2.1. 洪水演算 洪水演算过程基本方程 2.涉及专业知识或模型 2.1. 洪水演算 Outflow Description QO1 The Outflow from two low tainter gate QO2 The Outflow from two high tainter gate QO3 The Outflow from Log chute QO4 The Outflow from turbine 2.2.Outflow计算 水力学理论计算流量 水位流量曲线 Brown Bridge Discharge Capacity Discharge rating relationships were developed based on basic weir and orifice flow equations for the gates (two upper Tainter gates, two lower Tainter gates, and log chute sluice gate). This slides shows sample maximum discharge rating curves for Brown Bridge Dam The rating is slightly lower (more conservative) than the discharge capacity estimated by MACTEC (2011), which ignores losses at trash rack and at the entrance. The discharge rating does not include flow through the two turbines. The calculations were done using Matlab. Control is based on the lower discharge estimate from basic weir and orifice equations using a single assumed value for the orifice coefficient and weir coefficient throughout the head range. Gate openings and discharge coefficients are assigned to each gate individually to enable calculating the total discharge for any combination of gate settings. It is noted that the Dam Inspection Report states that the lower Tainter gates cannot be opened with a pool level above elevation 792.5 ft. Given the head conditions controlling flow through the upper Tainter gates and the lower Tainter gates, this condition creates an unusual appearing rating curve where discharge capacity drops to zero for pool elevations in that transition range. Stream Flow Hydrographs at Brown Bridge Pond This slide presents hyd