Accession Number : ADP002250

Title :   Experimental Investigation of Forebody and Wing Leading-Edge Vortex Interactions at High Angles of Attack,

Corporate Author : NORTHROP CORP HAWTHORNE CA AIRCRAFT DIV

Personal Author(s) : Erickson,G. E. ; Gilbert,W. P.

Report Date : JUL 1983

Pagination or Media Count : 20

Abstract : An experimental investigation was conducted to assess the vortex flow-field interactions on an advanced, twin-jet fighter aircraft configuration at high angles of attack. Flow-field surveys were conducted on a small-scale model in the Northrop 0.41- by 0.60-meter water tunnel and, where appropriate, the qualitative observations were correlated with low-speed wind tunnel data trends obtained on a large-scale model of the advanced fighter in the NASA Langley Research Center 30- by 60-foot (9.1- by 18.3-meter) facility. Emphasis was placed on understanding the interactions of the forebody and LEX-wing vortical flows, defining the effects on rolling moment variation with sideslip, and identifying modifications to control or regulate the vortex interactions at high angles of attack. The water tunnel flow visualization results and wind tunnel data trend analysis revealed the potential for strong interaction between the forebody and LEX vortices at high angles of attack. In particular, the forebody flow development near the nose could be controlled by means of carefully-positioned radome strakes. The resultant strake-induced flow-field changes were amplified downstream by the more powerful LEX vortical motions with subsequent large effects on wing flow separation characteristics. (Author)

Descriptors :   *Vortices, *Flow fields, Interactions, Wings, Leading edges, Angle of attack, Aerodynamic configurations, Wind tunnel models, Flow separation, Flow visualization, Fighter aircraft

Distribution Statement : APPROVED FOR PUBLIC RELEASE