The Buoyancy and Variable Viscosity Effects on a Water Laminar Boundary Layer Along a Heated Longitudinal Horizontal Cylinder

Abstract

Small cross flow is induced in an otherwise axially symmetric laminar boundary layer when a uniform horizontal stream flows along the inner or outer surface of a heated horizontal cylinder. The magnitude of this cross flow depends on the ratio of the Grashof number to the square of the Reynolds number, based on the radius of the cylinder, and in its early stages grows linearly in the downstream direction. The report shows that the variable-viscosity effect can increase the velocity gradient and, hence, stabilize the laminar boundary layer; the cross-flow effect will decrease the velocity gradient and destabilize the laminar boundary layer over the upper half of the cylinder (or the pipe flow). Also, the boundary beyond which the cross-flow effect can overwhelm the variable-viscosity effect has been determined.

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Feb 01, 1977
Accession Number
ADA036377

Entities

People

  • Ivan Catton
  • Lun-shin Yao

Organizations

  • RAND Corporation

Tags

Communities of Interest

  • Energy and Power Technologies
  • Materials and Manufacturing Processes

DTIC Thesaurus Topics

  • Boundary Layer
  • Boundary Layer Control
  • Boundary Layer Transition
  • Buoyancy
  • Computational Fluid Dynamics
  • Fluid Dynamics
  • Fluid Flow
  • Fluid Mechanics
  • Free Stream
  • Heat Transfer
  • Hydrodynamics
  • Mechanical Properties
  • Pipe Flow
  • Reynolds Number
  • Shear Stresses
  • Temperature Gradients
  • Three Dimensional

Fields of Study

  • Physics

Readers

  • Combustion and Flow Dynamics.
  • Fluid Mechanics and Fluid Dynamics.
  • Wave Propagation and Nonlinear Chaotic Dynamics.