System With Time Scale Distortion Study On Improvement Measures Of Navigation Flow Condition In The Entrance Area Of Second Line Ship Lock Of Mengli Project

Beijiang is the second largest river in the Pearl River,it connects the northern part of Guangdong and the Pearl River Delta area,the development on both sides of the river has a pivotal role.To further open the Beijiang River up to 1000 t route,on the upper reaches of the rest of the Shaoguan area to Wushi section 41 km to carry out remediation,among them,Meng Li hub in the second tier ship lock engineering is the key point of this project.In view of this topic is in the whole project has been completed under the premise of renovation and expansion,coupled with first-line,second-line shiplock are located on the right bank,besides the layout of the project and the relationship with the hub and the navigation conditions are extremely complex.This paper based on the Mengli hydro-junction project,through a combination of two-dimensional mathematical model and physical model test method of Mengli hydro-junction in the second tier ship lock change expansion project in the upper reaches of the approach channel navigable hydraulics conditions of the inquiry,and the connection section and entrance area more navigable hydraulics problems put forward effective corrective measures.The main contents of this paper include:(1)In the comprehensive research at home and abroad under the condition of navigation information,for the influence factors of lock approach navigation flow condition,the formation mechanism of the adverse flow,navigation flow condition improvement measures are summarized.(2)Through the experimental research on the hydraulic model of the hydraulic model of the Meng Li project,we found the design scheme have more bad flow pattern,which can not meet the requirements of navigation.Therefore,two schemes are proposed to modify the scheme and the scheme.By summarizing the test results and considering various factors that modification scheme II can satisfy the test requirements,the navigation conditions are relatively good,better improve the other schemes in the oblique flow and recirculation in unfavourable flow conditions,and the difficulty in construction and engineering investment are smaller.(3)Starting with the numerical calculation method of two-dimensional water flow,the calculation principle of MIKE21 software is described from two aspects of the control equation and numerical solution.Then,the model is used to simulate the river selection,network file create,mesh,the model’s key parameter determination,numerical simulation of the process of solving are described.Finally,through the model test can know that: under the combination of different water level and flow,mathematical model can correctly simulated piloting crossing gate area flow pattern in the numerical calculation is feasible and can better conform to the actual requirements.(4)Numerical simulation study on navigation conditions modifications carried out,the results from the model,the numerical simulation results analysis three aspects were studied.The results of numerical simulation are analyzed and compared from the aspects of water level map,total water depth map and vector distribution map.The results show that the feasibility of the modified scheme Ⅱ is confirmed by the comparison between the physical model and the mathematical model.(5)Preliminary exploration of navigation Wall opening angle β,affect navigation wall opening width B of the opening area navigation lock guidance wall navigable flow conditions.By using single factor analysis method,combined with numerical simulation data,the formula of the relationship between the opening angle of the navigation wall and the width of the opening and the lateral velocity and the reflux velocity was fitted.