Accurate computations of the laminar flow past a square cylinder based on two different methods: Lattice-Boltzmann and finite-volume

Abstract

The confined flow around a cylinder with square cross-section mounted inside a plane channel (blockage ratio B = 1/8) was investigated in detail by two entirely different numerical techniques, namely a lattice-Boltzmann automata (LBA) and a finite-volume method (FVM). In order to restrict the approach to 2D computations, the largest Reynolds number chosen was Re = 300 based on the maximum inflow velocity and the chord length of the square cylinder. The LBA was built up on the D2Q9 model and the single relaxation time method called the lattice-BGK method. The finite-volume code was based on an incompressible Navier-Stokes solver for arbitrary non-orthogonal, body-fitted grids. Both numerical methods are of second-order accuracy in space and time. Accurate computations were carried out on grids with different resolutions. The results of both methods were evaluated and compared in detail. Both velocity profiles and integral parameters such as drag coefficient, recirculation length and Strouhal number were investigated. Excellent agreement between the LBA and FVM computations was found. (C) 2000 Elsevier Science Inc. All rights reserved.