Experimental and Numerical Investigation of Vortex Shedding of a Representative UCAV Configuration for Vortex Flow Control
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 26.74 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 six-component internal balance was then installed to measure aerodynamic forces and moments. Limited steady electronically scanned pressure data were 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 broad-banded dominant frequency of approximately 10 Strouhal number. Maximum suction pressure was seen to move forward on the wing leading edge as the wing vortex moved inboard with increasing angle-of-attack. The CFD results adequately predicted the force and moment data. However, the CFD comparison to the unsteady pressure data was not stellar: CFD frequently failed to predict the mean pressure coefficient and the frequency content of the signal.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 2003
- Accession Number
- ADA419099
Entities
People
- Doug R. Hall
- Terence A. Ghee
Organizations
- Naval Air Station Patuxent River