Research On Numerical Simulation Of The Impact Of The Length Of Transition Of Continuous Meandering River On Navigation

The transition section is the continuous meandering river's important component. It has the important influence to the continuous meandering river's flow and navigation. Through a lot of research for the meandering structure and characteristics of flow and sediment movement, we have basically mastered the meandering flow of the motion mechanism and characteristics. However, it is not perfect to the research of the navigable water flow and navigation conditions of the continuous meandering river. It is little to the research of the impact of the length of transition of continuous meandering river on navigation. The main purpose of this paper is to find out the minimum navigable scale of continuous meandering river, through the comparison of the parameters of ship motion.In the physical model experiment's foundation, this research uses the MMG model with numerical flow model to do the numerical simulation work. Through the calculation of the parameters of the ship's movement in different transition section, discuss minimum navigable scale of continuous meandering river to the first curve and second curve independent. The main contents and conclusions are:(1)Verified by physical model test data, this study shows that 3-D flow model and MMG ship maneuvering mathematical model can simulate flow and ship movement of continuous meandering river.(2)By calculating the flow of continuous meandering river, we find some special flow characteristics; by comparing the flow characteristics in different transition section of continuous meandering river, we find that the size of the length of transition section can impact the circulation section of the second curve and the back surface of transition section. We defined the critical length of the transition from flow characteristics.(3)When channel width of the ship in the first curve and second curve is same, we think the the first curve and second curve are independent, and define the length of transition section as the navigable length of the critical length of the transition in this continuous meandering river. Through discussion, we think the navigable length of the critical transition is minimum navigable scale of transition section of continuous meandering river.(4)Thought the calculation of the MMG ship maneuvering mathematical model, we find the minimum navigable scale of transition section increase with the increase of central angle of bend, and increase with the decrease of the bending radius. Fitting the calculated data, we get the formula of the minimum navigable scale of transition section of continuous meandering river.