Cranked Arrow Wing (F-16XL-1) Flight Flow Physics with CFD Predictions at Subsonic and Transonic Speeds
Abstract
The increasing capability of computational fluid dynamics (CFD) to simulate real airplane geometries and flow conditions is found in the literature for both fighter and transport airplanes. In the continuance of that trend, this report details the results of a comparative study of CFD and flight data for the F-16XL-1 airplane over a wide range of test conditions from transonic to subsonic speeds. Though this airplane is not new, its cranked-arrow planform is relevant to any high-speed (supersonic) fighter or transport configuration. The flow physics understanding sought for the F-16XL-1 airplane was the subject of the Cranked-Arrow Wing Aerodynamics Project (CAWAP), and consisted primarily of surface features, such as pressures, local flow, boundary layers, and skin friction. Selected comparisons of predicted and measured quantities at 1g-flight from reference 6 form the scope of this paper. The CFD modeling used in this study produced reasonably good global upper-surface pressure coefficient comparisons with measured flight data at both transonic and subsonic speeds at the angles of attack presented. Boundary layer comparisons showed the profiles to be reasonably well predicted inboard and under the primary vortex system. However, the secondary vortex profile was not well predicted either at the anticipated separation point or under the secondary vortex. Moreover, the flight data showed there was a vortex/boundary-layer interaction that occurred in the vicinity of the secondary vortex. The spanwise distribution of local skin friction measured data was reasonably well predicted, especially away from the wing leading edge. Lastly, predicted and measured flight pressures as well as flight-image data for the F-16XL-1 fighter airplane are now available via the World Wide Web. (16 figures, 16 refs.)
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 2003
- Accession Number
- ADA419020
Entities
People
- John E. Lamar
Organizations
- National Aeronautics and Space Administration