Numerical Simulation On Waterway Regulation Of Fuling To Fengdu Reach Of Yangtze River

Due to Fuling to Fengdu reach is located in the pernancent backwater region of Yangtze River,the navigation-obstructing characteristics and obstruction mechanism of Fomiantan beach,touwailiang beach and Laohuliang beach change along with the water level period.Laohuliang beach,in particular,its boundary condition includes microbend and branching patterns,the reef shoals characteristics are very complicated.Therefore,it is very important to the study of reef shoals characteristics and renovation measures.According to the inland waterway regulation research status,flow mathematical model development and measured terrain hydrological data of Laohuliang beach of Yangtze River,this paper establishes the two-dimensional flow mathematical model,analyzes the navigation-obstructing characteristics and causes,puts forward the renovation ideas,parameters and optimization solutions,studies the changes of the flow condition before and after the project,and decides the optimal scheme.The main contents of this paper are:?The model validation.This paper verifies the model using the measured data of water level,flow velocity and direction under the flow of flood season and low level period.The result shows that the model and numerical method are reasonable.?The selection of scheme evaluation indexes.This paper takes into account the parameters who can reflect the current situation and the difficulty of ship maneuvering,and chooses current speed,lateral velocity,lateral to vertical ratio of velocity,running resistance and thrust to drag ratio to evaluate the effect of reef blasting scheme fully and accurately,and chooses explosive depth efficiency to analyze the marginal effect of different depth.? The selection of conditions and the most unfavorable flow.This paper chooses 8 typical flow-level combinations to carry out the flow simulation under intensive conditions,analyzes the flow condition under each flow-level combination to find out the most unfavorable flow by considering the designed lowest navigable water level,flooding water level and the worst flow level of Laohuliang beach,and decides to flow Q=24500m/s as the most unfavorable flow.?The study on the reef shoals characteristics.This paper analyzes the causes of the reef shoals,navigation-obstructing characteristics and the reasons of obstruction based on the measured data such as topography,hydrology and navigation and combined with the mathematical model.Due to the navigation-obstructing rocks into the channel,the flow pattern is very chaotic and over-ledge current is very strong in flood season.thrust to drag ratio is less than 1,and the ship navigation is difficult to operate when the flow is more than 24500m3/s.?The study on the determination of renovation parameters and optimal scheme.This paper combines with the navigation-obstructing characteristics and renovation principle,decides the depth,baseline and platform as renovation parameters,compares the effects of multiple depth schemes,two kinds of baseline schemes and several kinds of platform schemes,and decides platform scheme 8&6 as the optimal scheme.