Robust coupled fluid-particle simulation scheme in Stokes-flow regime: Toward the geodynamic simulation including granular media

2014 ◽  
Vol 15 (7) ◽  
pp. 2865-2882 ◽  
Author(s):  
Mikito Furuichi ◽  
Daisuke Nishiura
Keyword(s):  
Flow Regime ◽  
Stokes Flow ◽  
Granular Media ◽  
Fluid Particle ◽  
Particle Simulation ◽  
Simulation Scheme

Nonlinear hydrodynamic phenomena in Stokes flow regime

2010 ◽  
Vol 239 (14) ◽  
pp. 1214-1224 ◽  
Author(s):  
J. Blawzdziewicz ◽  
R.H. Goodman ◽  
N. Khurana ◽  
E. Wajnryb ◽  
Y.-N. Young
Keyword(s):  
Flow Regime ◽  
Stokes Flow

scholarly journals Mechanical models of sandfish locomotion reveal principles of high performance subsurface sand-swimming

2011 ◽  
Vol 8 (62) ◽  
pp. 1332-1345 ◽  
Author(s):  
Ryan D. Maladen ◽  
Yang Ding ◽  
Paul B. Umbanhowar ◽  
Adam Kamor ◽  
Daniel I. Goldman
Keyword(s):  
High Speed ◽  
High Performance ◽  
Granular Media ◽  
The Body ◽  
Physical Models ◽  
Particle Simulation ◽  
Sinusoidal Wave ◽  
Drag Forces ◽  
Single Period ◽  
Discrete Particle Simulation

We integrate biological experiment, empirical theory, numerical simulation and a physical model to reveal principles of undulatory locomotion in granular media. High-speed X-ray imaging of the sandfish lizard, Scincus scincus , in 3 mm glass particles shows that it swims within the medium without using its limbs by propagating a single-period travelling sinusoidal wave down its body, resulting in a wave efficiency, η , the ratio of its average forward speed to the wave speed, of approximately 0.5. A resistive force theory (RFT) that balances granular thrust and drag forces along the body predicts η close to the observed value. We test this prediction against two other more detailed modelling approaches: a numerical model of the sandfish coupled to a discrete particle simulation of the granular medium, and an undulatory robot that swims within granular media. Using these models and analytical solutions of the RFT, we vary the ratio of undulation amplitude to wavelength ( A / λ ) and demonstrate an optimal condition for sand-swimming, which for a given A results from the competition between η and λ . The RFT, in agreement with the simulated and physical models, predicts that for a single-period sinusoidal wave, maximal speed occurs for A / λ ≈ 0.2, the same kinematics used by the sandfish.

Double-Layer Representation of Model Microorganisms by a Boundary Element Method

2012 ◽  
Author(s):  
Kohei Kyoya ◽  
Yohsuke Imai ◽  
Takami Yamaguchi ◽  
Takuji Ishikawa
Keyword(s):  
Boundary Element Method ◽  
Boundary Element ◽  
Flow Regime ◽  
Double Layer ◽  
Stokes Flow ◽  
Biomedical Engineering ◽  
Many Body ◽  
Body Interaction ◽  
Many Body Interactions ◽  
Element Method

Analysis of a suspension of microorganisms is important in environmental and biomedical engineering. Previous studies had problems of high computational load in simulating many-body interaction of non-spherical swimmers. In this study, we propose a boundary element method (BEM), based on the double-layer representation, for calculating interactions of two squirmers in Stokes flow regime. By comparing the trajectories of squirmers calculated by both single- and double-layer representations, we show the accuracy of the method. The developed method has potential to deal with many-body interactions of non-spherical microorganisms.

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