Abstract
Training structures in flow stream play an important role in shaping flow and bed properties. To investigate consequences of introducing training elements like groins or dikes into the river stream one can successfully use numerical modelling. This paper is the second part of the research concentrated on utilizing some hydrodynamic models for resolving the problem. In the first part some hydrodynamic background has been described and here the analysis of applying two-dimensional depth-averaged model for straight rectangular channel with a groyne is discussed. Three models of eddy viscosity were applied to investigate their influence on results of simulation and to attempt choosing the most suitable method of modelling the flow phenomena around the groin. Results of simulation in steady flow conditions show that from the hydrodynamic point of view the more profitable method of turbulence description is the mixed-length or even the parabolic method instead of the broadly suggested k-e model. They allow producing the most reliable vortexes in the shear layer of flow behind the training structure end well preserve the mass balance contrary to the results obtained with k-e model of eddy viscosity.
Highlights
This is the second part of the research effort concentrated on the numerical modelling of flow near the groyne
Analysing time processes of several model’s runs, it appeared that in most cases around 54 seconds is consumed by the process of spinning up the model to obtain the solution that can be considered as the final state of the given steady flow
Three series of simulations has been conducted in the frame of this research and they were grouped in three different cases: Case 1 comprises all simulations for mixed-length model of eddy viscosity, Case 2 gathers all solution with parabolic EV model, and, Case 3 contains all results obtained with k-e model of EV
Summary
This is the second part of the research effort concentrated on the numerical modelling of flow near the groyne. Paper [3] contains detailed measurement and analysis results for flow parameters, shear stress fields and other quantities as functions of groyne length. Another work [6] referenced Rajaratnam’s results with depth-averaged simulation of hydrodynamic flow field in a groyne proximity. In [8], two different methods for the turbulence closure are introduced - the depth-averaged parabolic and modified mixed-length model but without any comparison between solutions based on that turbulence models. Another reviewed paper [9] contains more advanced applications of 2D depth-averaged hydrodynamic model for river flow with series of permeable pile groins using k-e eddy viscosity model. Model k-e models produced different solutions (Fig. 3) for each water flow parameters
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
