Accession Number:

ADA270932

Title:

The Fluid Mechanics of Vortex Cutting by a Blade

Descriptive Note:

Final rept. 1 Aug 92-31 Jul 93,

Corporate Author:

FLORIDA ATLANTIC UNIV BOCA RATON

Personal Author(s):

Report Date:

1993-09-25

Pagination or Media Count:

32.0

Abstract:

A study of the nonlinear response of a vortex to the approach of, and cutting by, a blade traveling in the plane normal to the vortex axis has been Performed. Two different types of vortex forces on the blade are distinguished. For large values of the ratio of blade thickness TAU to vortex ambient core radius sigma sub OMICRON, the force on the blade is primarily due to decreased pressure near the blade leading edge due to bending of the vortex about the blade. For values of TAUsigma sub OMICRIN of OMICRON1 or less, the vortex does not bend substantially during interaction with the blade and instead the blade passes through, or cuts, the vortex. In this case, the force on the blade is primarily due to formation of a vortex shock which propagates on the vortex away from the blade, and the subsequent difference in vortex core radius on opposite sides of the blade due to the vortex shock. This study was conducted based on analytical, computational and experimental studies, the results of which compared well in the regimes in which each are valid.

Subject Categories:

  • Fluid Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE