Spin-Up in a Rectangular Cylinder

Abstract

We examined the spin-up from rest of water in a rectangular cylinder. The presence of corners in the cylinder causes the formation of eddies. We found that the number of eddies, as well as eddy size, position, and rotation rate were dependent on the aspect ratio of the cylinder, the depth of the fluid, and the final angular velocity of the cylinder. Two time scales were found to be important in this experiment: the traditional Ekman number based on depth, which defines the time scale required for spin-up and an additional Ekman number based on the cylinder length which provides some information about the evolution of the fluid pathlines in route to spin-up. This second Eckman number appears to provide an explanation for both the agreement and disagreement of the experimental results herein and previously published results.

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Document Details

Document Type
Technical Report
Publication Date
Dec 01, 1993
Accession Number
ADA275465

Entities

People

  • Dawn L. Stewart

Organizations

  • Air Force Institute of Technology

Tags

Communities of Interest

  • Materials and Manufacturing Processes
  • Sensors
  • Weapons Technologies

DTIC Thesaurus Topics

  • Aspect Ratio
  • Boundary Layer
  • Computational Fluid Dynamics
  • Computational Science
  • Coordinate Systems
  • Differential Equations
  • Equations
  • Equations Of Motion
  • Flow Visualization
  • Fluid Dynamics
  • Fluid Mechanics
  • Froude Number
  • Measurement
  • Navier Stokes Equations
  • Photographs
  • Quantum Properties
  • Turbulent Mixing

Readers

  • Computational Fluid Dynamics (CFD)
  • Electromagnetic Wave Scattering and Antenna Radiation Engineering
  • Library and Information Science/ Studies, Southeast Asia Studies, Bibliography of Vietnam and Lao Studies.