Experimental Study of Apex Fences for Lift Enhancement on a Highly Swept Delta Wing Configuration.
Abstract
The longitudinal stability characteristics of a 60 deg. delta wing/body model equipped with various types of apex fences were studied experimentally. The experimental effort used force balance instrumentation and oil flow visualization. The locations of the fence-generated vortices and leading-edge vortices associated with highly swept wings were also determined. Five major fence parameters (shape, surface area, cant, length-to-height, movement) were studied and the results are given in a qualitative analysis. Results indicate a favorable application of apex fences for STOL operations. The fences increase lift and positive pitching moment which dictates the use of trailing edge flaps, further increasing the available maximum lift for takeoff and landing. Accompanying this is a large increase in drag at low angles of attack and a marginal increase at moderate to high angles. The relative strength of nose-down pitching moments at high (above 35 deg. angles of attack produced by apex fences is slight. Apex fences seem to be a technology whose time may have come. Further research of the lateral behavior of a 'fenced' aircraft appears warranted. Keywords: Apex fences; Vortex fences; Vortex flaps; (Theses).
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1985
- Accession Number
- ADA163877
Entities
People
- Michael Stuart
Organizations
- Air Force Institute of Technology