Large Eddy Simulations of Three-Dimensional Flow Around a Pipeline in a Uniform Current

Abstract

Three-dimensional (3D) modeling of the flow around a circular cylinder in a steady, uniform current subjected to low and intermediate Reynolds numbers (Re) is considered. Large eddy simulations (LES) are used to simulate the flow due to their ability to study fine structures in the turbulent wake of the cylinder. The turbulence is resolved by the Smagorinsky model. The open-source code OpenFOAM is used in the simulations. Influences of various numerical parameters, such as the grid resolution close to the cylinder, domain width and spanwise resolution are investigated through mean values of the drag and the lift coefficients, the Strouhal number, as well as through the details of the flow field in the near wake of the cylinder.

The main purpose of the present paper is to study the numerical influences on the 3D LES simulations of the flow around the cylinder in the free stream at Re = 13100. However, first the flow around a cylinder in the free stream at Re = 3900 is investigated. The latter case has previously been thoroughly investigated, both with LES and direct numerical simulations (DNS); hence these results will be used for verification of the OpenFoam solver.

At Re = 13100 the drag and lift coefficients and the Strouhal number are calculated for the comparable Re. Details of the flow in the intermediate wake of the cylinder are also investigated. So far, this has been investigated experimentally and by two-dimensional (2D) numerical simulations. Previous studies were conducted for moderate Re in the range 103–105.