Effect of wing tip vortices on a trailing aircraft

Abstract

T HE effect of trailing vortices from a large leading wing on a trailing aircraft is studied experimentally. The aerodynamic response of the trailing aircraft is examined through measurements of lift, drag, and pitching moment for various angles of attack of the two models and different separation distances between them. The results show that trailing vortices cause a remarkable loss of lift on the trailing aircraft. This phenomenon becomes more significant as the angle of attack of the leading object is increased. Results demonstrate that in order to maintain the same lift, drag would increase as the leading wing angle of attack is increased. Nomenclature C= chord length of the trailing aircraft C D = drag coefficient of the trailing aircraft C L = lift coefficient of the trailing aircraft CM = pitching moment coefficient of the trailing aircraft X = separating distance between the two models in the horizontal plane Y = separating distance between the two models in the vertical plane a.= trailing aircraft angle of attack (} = leading wing angle of attack

Wake Sensing for Aircraft Formation Flight

“…For example, some investigators have considered the optimal downwash and lift distribution of formation-flying wings [6], while others have focused on approaches for the modeling and simulation of aircraft formations [7,8]. Many groups have attempted to better characterize, by way of wind-tunnel measurements, the effect of tip vortices and wake roll-up on the trailing aircraft [9][10][11][12][13]. Numerous flight tests have also been conducted to determine real-world feasibility and proof-of-concept for formation-flying missions.…”