Acoustic flows in viscous fluid: a lattice Boltzmann study

作者：Chen, Xiao-Peng^*; Ren, Hu

来源：International Journal for Numerical Methods in Fluids, 2015, 79(4): 183-198.

DOI：10.1002/fld.4045

• acoustic levitation
• lattice Boltzmann method
• potential theory
• acoustic streaming

Acoustic waves (or oscillating flows) cause both periodic flow and steady streaming around an obstacle. The nonlinear characteristic of such flows further induces acoustic radiation forces exerting on the surface of the obstacle, which is efficient to levitate or manipulate small partials. Two-dimensional lattice Boltzmann methods are applied to simulate the flows around cylinders in acoustic standing waves with moderate viscosity. Multiple relaxation time model coupled with far-field absorbing condition is applied. Our results show recirculating leading order flow in the Stokes layer with a characteristic velocity predicted by potential flow. The consequent Reynolds stresses induce two kinds of patterns of first-order steady streaming, namely, single and double layer streamings, respectively, according to the strength of the viscous effects. Compared with the theoretical analysis, the lattice Boltzmann simulation is accurate for both radiation forces and flow fields. Both numerical results and scaling analysis show that the viscous drag is linearly proportional to the thickness of the penetration depth, which is coincident with the low viscous cases.

• 出版日期2015-10-10
• 单位西北工业大学