Accession Number:

ADA243388

Title:

An Experimental Study of a Turbulent Wing-Body Junction and Wake Flow

Descriptive Note:

Technical rept. 1 Jun 1989-31 Aug 1991

Corporate Author:

VIRGINIA POLYTECHNIC INST AND STATE UNIV BLACKSBURG DEPT OF AEROSPACE AND OCEAN ENGINEERING

Report Date:

1991-09-01

Pagination or Media Count:

394.0

Abstract:

Extensive hot-wire measurements were conducted in incompressible turbulent flow around a wing-body junction. Measurements were performed adjacent to the body and up to 11.56 chord lengths downstream of the body. Junction wake flow entered an adverse pressure gradient region approximately 6 chord lengths downstream. This regions geometry approximated the aft portion of an aircraft fuselage or a submersibles hull. Body geometry was formed by joining a 32 elliptic nose to a NACA 0020 tail section at their respective maximum thickness locations. Measurements were taken with approach flow conditions of Re sub theta 6,300, and deltaT .513, where T is maximum body thickness. Results clearly show the characteristic horseshoe vortex flow structure. Which is elliptically shaped, with delWdel Y forming the primary component of streamwise vorticity. Near wall measurements show a thin layer of highly concentrated vorticity, underneath and opposite in sign to the primary vortex, which is created by the wall no-slip condition. Development of flow distortions and associated vorticity distributions are highly dependent on the geometry-induced pressure gradients and resulting flow skewing directions. A quantity known as the distortion function was used to separate distortive effects of secondary flow from those of the body and the local 2-D boundary layer. The distortion function revealed that adverse pressure gradient flow distortions grew primarily because of increasing boundary layer thickness.

Subject Categories:

  • Aerodynamics
  • Submarine Engineering
  • Fluid Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE