An Experimental Study of a Turbulent Wing-Body Junction and Wake Flow
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 region's geometry approximated the aft portion of an aircraft fuselage or a submersible's hull. Body geometry was formed by joining a 3:2 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 delta/T = .513, where T is maximum body thickness. Results clearly show the characteristic horseshoe vortex flow structure. Which is elliptically shaped, with del(W)/del 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.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1991
- Accession Number
- ADA243388
Entities
People
- J. L. Fleming
- R. L. Simpson
- William J. Devenport
Organizations
- Virginia Tech