Direct numerical simulation of particulate flows with an overset grid method

JOURNAL OF COMPUTATIONAL PHYSICS

卷:343

Article

Koblitz, A. R.¹  Lovett, S.²  Nikiforakis, N.¹  Henshaw, W. D.³ 

[1] Cavendish Lab, Dept Phys, JJ Thomson Ave, Cambridge CB3 0HE, England

[2] Schlumberger Gould Res Ctr, Madingley Rd, Cambridge CB3 0EL, England

[3] Rensselaer Polytech Inst, Dept Math Sci, Troy, NY 12180 USA

关键词: Particulate flow;    Overset grids;    Direct numerical simulation;    Incompressible flow;   

DOI  :  10.1016/j.jcp.2017.04.058

来源: Elsevier

【 摘 要 】

We evaluate an efficient overset grid method for two-dimensional and three-dimensional particulate flows for small numbers of particles at finite Reynolds number. The rigid particles are discretised using moving overset grids overlaid on a Cartesian background grid. This allows for strongly-enforced boundary conditions and local grid refinement at particle surfaces, thereby accurately capturing the viscous boundary layer at modest computational cost. The incompressible Navier-Stokes equations are solved with a fractional- step scheme which is second-order-accurate in space and time, while the fluid-solid coupling is achieved with a partitioned approach including multiple sub-iterations to increase stability for light, rigid bodies. Through a series of benchmark studies we demonstrate the accuracy and efficiency of this approach compared to other boundary conformal and static grid methods in the literature. In particular, we find that fully resolving boundary layers at particle surfaces is crucial to obtain accurate solutions to many common test cases. With our approach we are able to compute accurate solutions using as little as one third the number of grid points as uniform grid computations in the literature. A detailed convergence study shows a 13-fold decrease in CPU time over a uniform grid test case whilst maintaining comparable solution accuracy. (C) 2017 Elsevier Inc. All rights reserved.

【 授权许可】

Free