Accession Number : ADP002247

Title :   An Experimental Investigation of the Vortex Flow over Delta and Double-Delta Wings at Low Speed,


Personal Author(s) : Verhaagen,N. G.

Report Date : JUL 1983

Pagination or Media Count : 16

Abstract : A wind-tunnel investigation was performed to study, by employing a laserlight-sheet and oil-flow visualization technique, the flow above and behind a sharp-edge 76 deg, delta wing and two sharp-edged double-delta wing models (76/60 and 76/40 deg., kink at midcord). In addition, balance measurements were performed to determine lift, drag and pitching moment. The tests were carried out for angles of attack from 5 to 25 deg. and at a free-stream velocity of 30 m/sec, corresponding to a Reynolds number of 1400000 x 10 to the 6th power, based on centerline chord. Above both double-delta wings a single-branched strake vortex is formed fed by vorticity from the strake leading edge. Downstream of the leading-edge kink a wing vortex is formed which is conjectured to be single-branched at about 5 deg, angle of attack and double branched at angles of 10 deg., an beyond. The flow pattern downstream of the trailing edge of the 76/60 deg. double-delta wing has been observed to be similar to that behind the delta wing. Above the 76/40 deg. double-delta wing breakdown of both the wing and strake vortices took place ahead of the trailing edge. (Author)

Descriptors :   *Vortices, *Delta wings, Aerodynamic characteristics, Flow fields, Angle of attack, Oils, Flow visualization, Wind tunnel tests, Wind tunnel models, Netherlands

Distribution Statement : APPROVED FOR PUBLIC RELEASE