Velocity relaxation of a particle in a confined compressible fluid

• Tatsumi, Rei

• Yamamoto, Ryoichi

Abstract

The velocity relaxation of an impulsively forced spherical particle in a fluid confined by two parallel plane walls is studied using a direct numerical simulation approach. During the relaxation process, the momentum of the particle is transmitted in the ambient fluid by viscous diffusion and sound wave propagation, and the fluid flow accompanied by each mechanism has a different character and affects the particle motion differently. Because of the bounding walls, viscous diffusion is hampered, and the accompanying shear flow is gradually diminished. However, the sound wave is repeatedly reflected and spreads diffusely. As a result, the particle motion is governed by the sound wave and backtracks differently in a bulk fluid. The time when the backtracking of the particle occurs changes non-monotonically with respect to the compressibility factor ε = ν∕ac and is minimized at the characteristic compressibility factor. This factor depends on the wall spacing, and the dependence is different at small and large wall spacing regions based on the different mechanisms causing the backtracking.

Journal

• The Journal of chemical physics

  The Journal of chemical physics 138 (18), 2013-05-14

  American Institute of Physics

Keywords

• acoustic waves
• backtracking
• boundary layers
• compressible flow
• confined flow
• diffusion
• flow simulation
• numerical analysis
• shear flow
• two-phase flow

Details

• CRID: 1050282810749159936
• NII Article ID: 120005298337
• NII Book ID: AA00694991
• ISSN: 00219606
• HANDLE: 2433/175968
• Text Lang: en
• Article Type: journal article
• Data Source:
  • IRDB
  • CiNii Articles