A Critical Review of the Drag Force on a Sphere in the Transition Flow Regime

Abstract

Improvements in micro-fabrication techniques are enabling Micro-Electro-Mechanical-Systems to be constructed with sub-micron feature sizes. At this scale, even at standard atmospheric conditions, the flow is in the transition regime. This paper considers the range 0.1 < Kn < 1, where non-equilibrium effects can be appreciable, and specifically illustrates problems involving non-planar surfaces by analyzing the drag force for low speed, incompressible flow past an unconfined microsphere. A critical comparison is made between experimental data, analytical solutions derived from kinetic theory, Grad's thirteen-moment equations, and the Navier-Stokes equations with first- and second-order treatment of the slip boundary. The results, even for this simple geometry, highlight major problems in predicting the drag in the transition flow regime for non-kinetic schemes.

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Jul 13, 2005
Accession Number
ADA446065

Entities

People

  • C. L. Bailey
  • D. A. Lockerby
  • D. R. Emerson
  • J. M. Reese
  • R. W. Barber

Organizations

  • King's College London

Tags

Communities of Interest

  • Biomedical

DTIC Thesaurus Topics

  • Equations
  • Experimental Data
  • Flow
  • Fluid Dynamics
  • Fluid Mechanics
  • Gas Flow
  • Kinetic Theory
  • Knudsen Number
  • Mean Free Path
  • Mechanical Properties
  • Mechanics
  • Microelectromechanical Systems
  • Navier Stokes Equations
  • Particles
  • Slip Flow
  • Specific Heat
  • Transitions

Readers

  • Aerodynamics.
  • Integrated Circuit Design and Technology.
  • Plasma Physics / Magnetohydrodynamics

Technology Areas

  • Microelectronics