Title: A numerical study on shear layer behaviour in flow over a square unit of four cylinders at Reynolds number of 200 using the LB method

Authors: Javad A. Esfahani; Ahmad Reza Vasel-Be-Hagh

Addresses: Centre of Excellence on Modelling and Control Systems & Department of Mechanical Engineering, Ferdowsi University of Mashhad, Mashhad 91775-1111, Iran ' Centre of Excellence on Modelling and Control Systems & Department of Mechanical Engineering, Ferdowsi University of Mashhad, Mashhad 91775-1111, Iran

Abstract: The major purpose of the present research is developing the Lattice Boltzmann (LB) method as an extremely efficient computational technique in the pragmatic field of fluid-structure interactions. Hence, the LB method is employed in simulating the incompressible flow past a square unit of four equal diameter circular cylinders. The simulation is conducted at Re of 200 and the spacing ratio (L/D) increases from 1.5 to 5 in 0.5 steps to cover all closely, moderately and widely spaced cases. Accordingly, the effects of the spacing ratio on the shear layer's behaviour and vortex shedding pattern are studied in detail. Furthermore, its effects on the main force characteristics, i.e., lift and drag coefficients and also the Strouhal number are fully investigated. The observations and results obtained by the LB method employed in the current work are in strict accordance with experimental evidence of other researchers and other existent numerical data in the literature.

Keywords: shear layer behaviour; deflected vortex shedding; synchronised vortex shedding; in-phase mode; anti-phase mode; force characteristics; Lattice Boltzmann method; Reynolds number; fluid-structure interactions; simulation; incompressible flow.

DOI: 10.1504/PCFD.2013.052425

Progress in Computational Fluid Dynamics, An International Journal, 2013 Vol.13 No.2, pp.103 - 119

Published online: 31 Oct 2013 *

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