Nonlinear Theory Of Dynamic Evolution Process For Constant Curvature Channels

The rivers in the nature can be classified in three types:straight rivers, meandering rivers and braided rivers. Meandering is the most common type of rivers in the nature. The studying on dynamic evolution process of meandering rivers has great value both in theory and practical application. The value in theory is that the studying on meandering rivers is the most popular part in dynamic evolution process studying of rivers. And the applying in engineering is its value in practical application.The characteristics of the evolution process of meandering rivers are:the meander is always in the process of occurring, developing and dying. After the meanders arising, the riverbed is always changing as the concave bank is eroded and the convex bank is deposited. Now, people are paying more and more attention on dynamic evolution process of meandering rivers.In this paper, the dynamic evolution process of meandering rivers is studied. The flow movement control equations in curvilinear coordinates were established. The flow movement control equations were depth-integrated and then were turned into dimensionless. The velocities of flow and the bed topography were solved by the method of perturbed expansion. The nonlinear theory of dynamic evolution process for constant curvature channels was studied. Using the equations, a mathematic model was established to compare its results with others’ results and experimental data. The results we get in this paper match up with the actual situation well, especially in the situation of high Reynolds number.