Title: A note on modelling non-rectangular boundaries by the Lattice Boltzmann Method

Authors: E. Aslan; A. Nahavandi; I. Taymaz; A.C. Benim

Addresses: Department of Mechanical Engineering, Sakarya University, TR-54187 Sakarya, Turkey ' CFD Lab, Department of Mechanical and Process Engineering, Dusseldorf University of Applied Sciences, Josef-Gockeln-Str. 9, D-40474 Dusseldorf, Germany ' Department of Mechanical Engineering, Sakarya University, TR-54187 Sakarya, Turkey ' CFD Lab, Department of Mechanical and Process Engineering, Dusseldorf University of Applied Sciences, Josef-Gockeln-Str. 9, D-40474 Dusseldorf, Germany

Abstract: The classical Lattice Boltzmann Method is based on an orthogonal, equidistant lattice structure. Thus, representation of non-rectangular boundaries deserves further attention. Besides the straightforward possibility of representing a non-rectangular boundary by a staircase, there are more sophisticated approaches in the literature for an accurate modelling of a non-rectangular boundary. In the present paper, three such methods are compared with each other, and with the straightforward staircase approximation on two laminar flow test cases. As the reference solution, results obtained by a commercial CFD code are used, which are obtained by an exact representation of the non-orthogonal boundaries, using non-orthogonal finite volume discretisation. The results show that the so-called extrapolation method's performance is slightly inferior compared to the other methods; however, all methods exhibit a comparable overall accuracy.

Keywords: non-rectangular boundaries; lattice Boltzmann method; modelling; laminar flow; CFD; computational fluid dynamics; finite volume discretisation.

DOI: 10.1504/PCFD.2012.049815

Progress in Computational Fluid Dynamics, An International Journal, 2012 Vol.12 No.6, pp.433 - 438

Received: 08 May 2021
Accepted: 12 May 2021

Published online: 15 Oct 2012 *

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