Research On Navigable Water Flow Conditions Of Curved Intermediate Channel With Ship Locks At Both Ends

With the rapid development of inland shipping in my country,the river hubs located in mountainous areas need to be expanded and reconstructed.However,the layout of curved channels is often encountered in the design of shipping hubs in mountainous areas,and conventional straight channels are difficult to meet the navigation requirements due to terrain constraints.Therefore,the navigation method of the ship lock-curved intermediate channel is widely used to solve the navigation problem of the lock dam or the capacity expansion project under such conditions.However,the unsteady flow during the operation of the locks at both ends will cause surges,reflections and other phenomena in the middle channel,and at the same time change the water level amplitude and current fluctuation in the curved section,forming a more complex navigable water flow than the conventional lock-intermediate channel.condition.It can be seen that the unsteady flow characteristics and water flow conditions in the curved intermediate channel are the key hydraulic technical issues affecting the operation safety of the ship locks at both ends and the safety of ship navigation.So far,there are few research results on this issue at home and abroad.This thesis takes the curved intermediate channel with ship locks at both ends as the research object,and uses a two-dimensional turbulent mathematical model to study the navigable water flow conditions of the curved intermediate channel.The main results are as follows:(1)Different ship lock operation modes have a significant impact on the navigable water flow conditions of the intermediate channel.When the upstream and downstream ship locks operate at the same time,the water flow conditions in the intermediate channel are the worst;The channel water flow conditions,in which the first-drain and thenirrigation method is better than the first-irrigation and then-drain mode,which can be used as the best operating condition;The irrigation of the downstream ship lock can easily cause the local water depth of the channel to be insufficient,which is the control of the initial water depth of the intermediate channel condition.(2)The changes of the central angle θ and the bending radius R of the curved section have a greater impact on the water flow conditions in the curved section of the intermediate channel,the main hydraulic parameters that affect the navigable water flow conditions in the curved section of the intermediate channel are wave height,water surface gradient,and section velocity.(3)The central angle θ and bending radius R of the curved section are positively correlated with the maximum water level amplitude and the maximum oscillating wave height in the curved section of the intermediate channel;The increase in the length of the curved section will aggravate the water level amplitude and water flow fluctuation in the curved section,which directly affects the navigation safety of ships in the curved section.(4)The change of the central angle θ and the bending radius R of the curved section has little effect on the maximum water surface gradient of the curved section;Only when the upstream and downstream ship locks are filled and discharged at the same time,the curved section will have a large lateral gradient.Under other conditions the water surface gradient in the bending section is mainly manifested as the longitudinal water surface gradient.(5)When the central angle θ and the bending radius R of the curved section are changed,the maximum flow velocity value in the curved section of the intermediate channel is not greatly affected by it;Different ship lock operation modes will lead to different changes in the flow velocity in the bending section and different positions of the maximum flow velocity;The variation trend of the inner and outer flow velocity in the curved section of the middle channel is the same,the inner side of the curve gradually decreases along the outer direction,and the inner velocity is always greater than the outer velocity,and the main flow line is always located in the inner side of the curved section.