Abstract:
This work constructs a mathematical model and a computational method to get extensive data about the structure of a river stream essential for predicting the behavior of a river. The model proposed is based on depth-averaged Reynolds-averaged Navier-Stokes equations. The solver is based on the finite volume method on a staggered structured grid and a high-order Monotonic Upwind Scheme for Conservation Laws for convective fluxes. The solution is obtained with a Semi-Implicit Method for Pressure Linked Equations iterative algorithm based on coupled correction of the depth and velocity fields at each time step. The principal innovation of the algorithm proposed is accounting for the variability of the water depth in the source term in the momentum equations. The results show that the approach proposed accurately predicts the flow field and concentration field and demonstrate the significant role of the flow turbulence in transport of pollution in the river stream.
Keywords:open channel flow turbulence, turbulence simulation and modelling, RANS models, shallow flows, streams and rivers, water quality.