Simulation Test Research On Ship Maneuverability Of Water Intake Arrangement In Power Station Expansion Project

The Jinweizhou hub project is located in the Xiangjiang River basin,at the junction of four counties in Hunan,such as Changning and Qidong.Due to the channel currently not meeting the growing shipping demand,it is necessary to carry out a power station expansion project for the hub.There is a conflict between the layout of the expanded hydraulic generator and the second line ship lock in this expansion project,which is sandwiched between the first and second line ship locks,and it is necessary to rearrange the upstream and downstream approach channels.Therefore,the smoothness of the connection with the approach channel is insufficient,and the navigation environment of the relevant river section is relatively complex.After the expansion project,there are still some safety issues in the existing hub layout scheme: the most serious ones are that the adverse flow regime near the intake exceeds the standard under partial flow conditions,and the rudder angle generated by ships sailing under partial flow conditions does not meet the safety limits.Therefore,in order to improve the navigation safety of passing ships,it is necessary to optimize the layout plan of the upstream channel water intake of the first-line ship lock,and control the project budget while making the layout reasonable.Therefore,a series of physical model tests were conducted on the first-line ship lock after the hub expansion project to study the above issues and provide technical support for subsequent research.The layout of water intakes often has a significant impact on the navigation safety of passing ships.In the past,research and verification of their layout schemes have mostly been carried out through hydraulic models and ship model tests.By analyzing a large amount of test data,it is time-consuming and laborious,and the preparation period of physical model tests is long,and it is difficult to modify them later.Therefore,it is very necessary to study the maneuvering performance of ships near the water intake through mathematical models.Based on the ship model test and hydraulic model test of the upstream channel of the Jinweizhou lock on the Xiangjiang River,this thesis proposes a scheme for further optimizing the layout of the intake of the upstream channel of the lock on the first line of the hub,selects relevant river sections to establish a 3-degree of freedom separation type mathematical model for ship maneuvering motion,and conducts numerical simulation of ship motion in relevant river sections.The main research contents and relevant conclusions are as follows:(1)Based on the existing layout plan for the upstream channel water intake of the Xiangjiang River near Weizhou Shiplock,the problems existing in the existing layout plan were studied and analyzed,and three optimization plans were initially determined.Then,the flow conditions of the three layout plans were analyzed through modeling software,and the analysis results were compared to determine the optimal layout plan for navigation flow conditions.After the layout scheme is determined,it lays the foundation for subsequent numerical simulation of ship maneuvering.(2)Based on the mathematical model of MMG ship maneuvering motion in deep water,a mathematical model of ship maneuvering motion in shallow water is established,and the discrete solution method of the mathematical equation is introduced;Using MATLAB software and computer language programming,the mathematical model was validated through known data,and ship rotation tests and ship Z-type tests were conducted under different rudder angles and water depths.The test results were good,laying a foundation for subsequent research and providing technical support.(3)Using the mathematical model of ship manoeuvring motion constructed in the previous article,different operating conditions are carried out for the determined reach of the upstream channel intake of the Xiangjiang River near Weizhou lock,Experimental simulation of ship manoeuvring under shallow water conditions with consideration of shore wall effects(since this article mainly studies the layout scheme of water intakes,the downward approach of ships is to drive from broad waters to narrow waters,with a high risk factor,while the upward exit of ships is to drive from narrow waters to wide waters,with a low risk factor,so this article only studies the situation of ships entering the lock downward).The experimental results show that the ship’s manoeuvring performance is excellent.The experimental results show that under all operating conditions,the speed of the ship during navigation is greater than 0.4 m/s,which conforms to the safety limit;Under all operating conditions,the rudder angle of the ship is less than25 °,which meets the safety limit.Under some operating conditions,it is close to the safety limit.In practical situations,it is necessary for the driver to drive carefully.Overall,the parameters of the ship during navigation fully comply with the safety limits.Therefore,it can be judged that under this layout plan,ships in relevant river sections can safely navigate,directly proving the rationality and feasibility of the layout plan for the upstream channel intake of the first-line ship lock of the hub determined in this article.