Study On Propagation Characteristics Of Unsteady Flow And The Effect Of Down Stream Navigation By Unsteady Flow Caused By Dispatching Operation Of Power Station

Dispatching operation of Hydro power Station changes flowing conditions of natural river,and can lead to Water level frequent change,sometimes the velocity is small, another times the velocity is big, flow regime is good sometimes bad,and has an unsteady flow wave impact on maintenance of channel,the safe navigation of the ship and the normal operation of port,wharf.In recent years, although people has carried out many studies in unsteady flow, but mostly studies are carried out for characteristics of unsteady flow in the shorter river through numerical simulation and physical model.The unsteady flow caused by daily regulation of Hydro power Station on has impact on the downstream of the dam,and the distance of affect is longer than the other.Few studies on Propagation characteristics in the long rive.Based on the xiangjiaba hydropower station as the research background, using the method of combining physical model and mathematical model to study characteristics of unsteady flow which caused by power station daily regulation. The model scale is1:100 and the total length is 750 m. On the basis of the unsteady flow of power plant,analyzed the influence on maintenance of channel,the safe navigation of the ship and the normal operation of port,wharf.Different river, its distance from the dam site, the river direction, bottom slope,cross section shape is different,Propagation velocity, water level amplitude, velocity and so on also show different propagation characteristics.Velocity besides related to water depth, flow, also associated with the bottom slope and shape of the cross section of the river.With a compound section of the river there are convex point water level, water level when the lowest water level less than bulge on the highest water level is greater than the convex point when the water level, water level of transformer will be the biggest day of abnormal happen, don’t. Power stations are in the process of the daily regulation increases the shoal reach the mutagenicity of channel depth and width, is advantageous to the sailing of the vessel, but daily regulation water level, flow velocity and flow pattern changing, safe and caused adverse impact on the navigation, navigation of ships to avoid these unfavourable moment.This research uses physical model of large scale to test the water level and velocity of long river downstream in real time measurement caused by power station daily regulation of constant current, andsummarizes the propagation characteristics of water level and velocity of long river downstream caused by unsteady flow of xiangjiaba power station, which lays the foundation to further research on the influence of unsteady flow which caused by daily regulation of Xiangjiaba Hydro power Station on navigation of ships.