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Tip Effects on Fluctuating Lift and Drag Forces Acting on a Circular Cylinder Perpendicular to an Air Flow


Blackiston, Harry Spencer (1963) Tip Effects on Fluctuating Lift and Drag Forces Acting on a Circular Cylinder Perpendicular to an Air Flow. Engineer's thesis, California Institute of Technology. doi:10.7907/TV46-TR33.


Tests were conducted to evaluate the tip effects on the local air loads that act on a circular cylinder normal to a flow at Reynolds numbers, based on cylinder diameter, of 0.38 x 106, 0.53 x 106, 0.65 x 106 and 0.75 x 106 (corresponding to wind tunnel dynamic pressures of 10, 20, 30, and 40 psf, respectively). Tip configurations consisted of a blunt-end (or smokestack), a hemisphere, a 15 degree half-angle cone, and an ellipsoid with semi-major axis of 1.5 cylinder diameters. Localized boundary layer tripping facilitated controlled disturbances near the tip.

Unsteady lift and drag were significantly altered by the hemispherical and ellipsoidal ends as compared with the blunt-end. In contrast, the conical tip showed much smaller changes. Local lift and drag coefficients, as well as cross-correlation coefficients, vary rapidly along the cylinder axis near the tip.

The importance of boundary layer characteristics on the fluctuating forces was demonstrated by boundary layer tripping with air blowing out through suitably located orifices in the cylinder.

Item Type:Thesis (Engineer's thesis)
Subject Keywords:(Aeronautical Engineering
Degree Grantor:California Institute of Technology
Division:Engineering and Applied Science
Major Option:Aeronautics
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Fung, Yuan-cheng
Thesis Committee:
  • Unknown, Unknown
Defense Date:1 January 1963
Record Number:CaltechETD:etd-12072005-135116
Persistent URL:
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:4834
Deposited By: Imported from ETD-db
Deposited On:08 Dec 2005
Last Modified:05 Jan 2024 00:39

Thesis Files

PDF (Blackiston_hs_1963.pdf) - Final Version
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