Applying of depth-averaged hydrodynamic modeling with different methods of turbulence closure for flow near channel groyne. Part II – Analysis of simulation

West Pomeranian University of Technology, Civil Engineering and Architecture Faculty, Al. Piastow 50, 70-311 Szczecin, Poland

^* Corresponding author: rewertowski@zut.edu.pl

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.