Analytical Model for Lateral Depth-Averaged Velocity Distributions in Rectangular Ice-Covered Channels

摘要

Based on the Reynolds-averaged Navier-Stokes equations and the Shiono and Knight method, this paper describes the development of an analytical model to predict the lateral distribution of depth-averaged velocities in steady uniform flows in rectangular ice-covered channels, including the effect of river bed resistance, ice sheet resistance, eddy viscosity, and secondary flows. The analytical model has three working conditions: full ice cover, symmetrical shore ice, and asymmetrical shore ice. The modeled results agreed well with the available experimental data, thereby indicating that the proposed model can accurately predict the lateral distribution of depth-averaged velocity in rectangular ice-covered channels. The application of dimensionless eddy viscosity, resistance coefficient, and secondary flow coefficient was analyzed. Results illustrate that the calculation method for the dimensionless eddy viscosity and resistance coefficient in open channels is also applicable to ice-covered channels. The study shows that secondary flow, which has a close relationship with flow depth, plays an important role in ice-covered channels. In the application of the model, ignoring the secondary flow will lead to a large computational error.