Three-Dimensional Rans Modeling of Flow Around Circular Piers using Nested Grids

Abstract

ABSTRACT:The paper introduces a three-dimensional numerical model that solves the Reynolds Averaged Navier-Stokes (RANS) equations on a curvilinear grid system using a novel nested grid approach. The main benefit of the model is the possibility to model locally complex hydraulic features in large rivers like the flow field at hydraulic structures. The entire study domain in such a case can be discretized with a coarser resolution, whereas a much finer resolution can be applied to a defined zone of the obstructions, where a detailed description of the flow field is needed. The model is tested on a laboratory experiment carried out at the Georgia Institute of Technology, where the flow field around a single and two double circular cylinders in a flatbed flume was studied. Simulated flow velocity, turbulent kinetic energy and bed shear stress distributions are in good agreement with measurements. However, deviations downstream of the piers indicate the limitation of the steady state description of the flow in the unstable wake zone. Nevertheless, the nested grid approach presented herein is a promising step towards the modeling of the local scouring phenomenon due to the relatively low computational demand.

Calibration of Horizontal Acoustic Doppler Current profilers by three dimensional CFD simulations

“…This has earlier been done by Olsen and Kjellesvig (1999), who computed flow in a desilting basin of the Svartisen Hydropower plant in Norway. Recently a number of numerical studies have been conducted where CFD is used to predict the flow fields for different hydraulic cases, as documented by Baghalian, Bonakdari, Nazari, and Fazil (2012), Haun, Olsen, andFeurich (2011), Chau andJiang (2004), Andersson, Andreasson, and Lundström (2013), Erduran, Seckin, Kocaman, and Atabay (2012), Chau and Jiang (2001), and Baranya, Olsen, Stoesser, and Sturm (2012).…”

Numerical investigation of flow and scour around a vertical circular cylinder

“…While much has been written on this subject, comparatively few studies have been presented involving detailed three-dimensional numerical modelling of such processes. Important contributions to the numerical investigation of both flow and scour around vertical piles include [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15].…”

Rans, detached Eddy simulation and large Eddy simulation of internal Torque converters flows: A comparative study

“…Figure 4 shows that all values of y-plus on the blades are less than 2. This result indicates that the mesh density in near-wall regions is acceptable (Barony, Olsen, Stoesser, & Sturm, 2012).…”