Simulation of dynamic fluid–solid interactions with an improved direct-forcing immersed boundary method--颗粒学报PARTICUOLOGY

Di, S., & Ge, W. (2015). Simulation of dynamic fluid–solid interactions with an improved direct-forcing immersed boundary method. Particuology, 18, 22–34. https://doi.org/10.1016/j.partic.2014.05.004

Simulation of dynamic fluid–solid interactions with an improved direct-forcing immersed boundary method

Shengbin Di ^{a b}, Wei Ge ^a *

a State Key Laboratory of Multiphase Complex System, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China
b University of Chinese Academy of Sciences, Beijing 100049, China

10.1016/j.partic.2014.05.004

Volume 18, February 2015, Pages 22-34

Received 8 January 2014, Revised 28 April 2014, Accepted 12 May 2014, Available online 19 August 2014.

E-mail: wge@ipe.ac.cn

Highlights

• A modified direct-forcing immersed boundary method was proposed.

• The improved method was implemented on a CPU–GPU hybrid supercomputer.

• The method was validated by different test problems.

• Simulation yielded accurate results in boundary vicinity, especially for moving boundaries.

Abstract

Dynamic fluid–solid interactions are widely found in chemical engineering, such as in particle-laden flows, which usually contain complex moving boundaries. The immersed boundary method (IBM) is a convenient approach to handle fluid–solid interactions with complex geometries. In this work, Uhlmann's direct-forcing IBM is improved and implemented on a supercomputer with CPU–GPU hybrid architecture. The direct-forcing IBM is modified as follows: the Poisson's equation for pressure is solved before evaluation of the body force, and the force is only distributed to the Cartesian grids inside the immersed boundary. A multidirect forcing scheme is used to evaluate the body force. These modifications result in a divergence-free flow field in the fluid domain and the no-slip boundary condition at the immersed boundary simultaneously. This method is implemented in an explicit finite-difference fractional-step scheme, and validated by 2D simulations of lid-driven cavity flow, Couette flow between two concentric cylinders and flow over a circular cylinder. Finally, the method is used to simulate the sedimentation of two circular particles in a channel. The results agree very well with previous experimental and numerical data, and are more accurate than the conventional direct-forcing method, especially in the vicinity of a moving boundary.

Graphical abstract

Keywords

Immersed boundary method; Fluid–solid interactions; No-slip condition; Divergence-free condition; CPU–GPU hybrid architecture

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