Radial lift on a suspended finite-sized sphere due to fluid inertia for low-Reynolds-number flow through a cylinder

Sukalyan Bhattacharya, Dil K. Gurung, Shahin Navardi

Research output: Contribution to journalArticlepeer-review

12 Scopus citations


This article describes the radial drift of a suspended sphere in a cylinder-bound Poiseuille flow where the Reynolds number is small but finite. Unlike past studies, it considers a circular narrow conduit whose cross-sectional diameter is only 1. 5-6 times the particle diameter. Thus, the analysis quantifies the effect of fluid inertia on the radial motion of the particle in the channel when the flow field is significantly influenced by the presence of the suspended body. To this end, the hydrodynamic fields are expanded as a series in Reynolds number, and a set of hierarchical equations for different orders of the expansion is derived. Accordingly, the zeroth-order fields in Reynolds number satisfy the Stokes equation, which is accurately solved in the presence of the spherical particle and the cylindrical conduit. Then, recognizing that in narrow vessels Stokesian scattered fields from the sphere decrease exponentially in the axial direction, a simpler regular perturbation scheme is used to quantify the first-order inertial correction to hydrodynamic quantities. Consequently, it is possible to obtain two results. First, the sphere is assumed to follow the axial motion of a freely suspended sphere in a Stokesian condition, and the radial lift force on it due to the presence of fluid inertia is evaluated. Then, the approximate motion is determined for a freely suspended body on which net hydrodynamic force including first-order inertial lift is zero. The results agree well with the available experimental results. Thus, this study along with the measured data would precisely describe particle dynamics inside narrow tubes.

Original languageEnglish
Pages (from-to)159-186
Number of pages28
JournalJournal of Fluid Mechanics
StatePublished - May 2013


  • Stokesian dynamics inside conduit
  • low-Reynolds-number particle migration
  • multiphase and particle-laden flows


Dive into the research topics of 'Radial lift on a suspended finite-sized sphere due to fluid inertia for low-Reynolds-number flow through a cylinder'. Together they form a unique fingerprint.

Cite this