Accession Number:

ADA393427

Title:

Experimental and Numerical Investigation of Vortex Shedding of a Representative UCAV Configuration for Vortex Flow Control

Descriptive Note:

Professional paper

Corporate Author:

NAVAL AIR WARFARE CENTER AIRCRAFT DIV PATUXENT RIVER MD

Personal Author(s):

Report Date:

1999-01-01

Pagination or Media Count:

16.0

Abstract:

A 4 Uninhabited Combat Air Vehicle UCAV has been extensively tested at low speeds in a wind tunnel to investigate using vortex flow control to control vehicle attitude. The program is the initial step to utilize experimental and computational techniques to understand the flowfield environment on a representative low-observable air vehicle and use that understanding to apply an efficient vortex flow control apparatus. Gross flow field characteristics were identified using flow visualization and the approximate vortex location was determined for a number of angles-of-attack for a tunnel dynamic pressure of 26.47 psf. From this study, the model was instrumented with pressure transducers at appropriate locations on the wing and unsteady data was acquired for a number of angles-of-attack and tunnel dynamic pressures. A limited hot-wire anemometry study was also conducted. A six-component internal balance was then installed to measure aerodynamic forces and moments. Limited steady electronically scanned pressure data was acquired. Computational fluid dynamic CFD analysis was conducted on the model geometry to compare with the results from the wind tunnel study. The results show two vortex structures a weak apex vortex and a stronger wing vortex. Wing vortex frequency exhibits a rather broad-banded dominant frequency between 6 and II Strouhal number. Maximum Suction pressure was seen to move forward on the wing leading edge with increasing angle-of-attack. The CFD poorly predicted the physical behavior of the vortex.

Subject Categories:

  • Pilotless Aircraft
  • Combat Vehicles
  • Fluid Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE