Near-surface particle image velocimetry measurements over a yawed slender delta wing

Abstract

In this study, extensive instantaneous velocity measurements were conducted within a flow area by stereo particle image velocimetry (SPIV) to investigate the influence of the yaw angle, β, on the vortical flow structure formed on a slender delta wing. This sideslip angle, β, in the yaw plane was varied from 4° up to 20° with an interval of 4° at two critical angles of attack, α = 25° and 35°, respectively. In order to reveal the influence of the yaw angle, β over the flow structure of the delta wing, time-averaged flow statistics, and instantaneous flow data obtained by the SPIV technique in the plan-view plane close to the suction surface of the delta wing were presented. It was observed that even a low yaw angle, for instance β = 8°, becomes to be effective on the flow characteristics of the delta wing, and this effect was augmented with increasing β. The influence of β is quite high on the vortical flow structure at α= 35° compared to the angle of attack of α = 25°. The flow structure that is symmetrical with respect to the centerline of the wing in the case of no yaw has disrupted with the existence β. Furthermore, the extent of the asymmetry enlarges with increasing β. The leading-edge vortex (LEV) on the windward side broken earlier and dominated the flow on the wing surface. It is concluded that this asymmetric flow structure can deteriorate the aerodynamic performance and cause other adverse effects such as unsteady loading.

Internal Aerodynamic Performance Enhancement for Aircraft with High Maneuver by Designing a Distributed Submerged Inlet

“…In order to simplify the problem, only the internal flow characteristics of the inlet during pitch maneuver and yaw maneuver are investigated [41][42][43]. In the course of pure pitch maneuver with constant incoming flow conditions, the angle of attack of the aircraft is equal to the angle of pitch; The angle of attack of the aircraft is equal to the sideslip angle during the simple yaw maneuver with the inflow conditions unchanged.…”

Investigation of periodic characteristics of perturbed flow over a slender body

“…In addition, the slender body was the basic geometry of fighter aircraft and missiles, hence, the highly random asymmetric flow was coupled with wings and induces a yawing moment [ 3 ], which was even largely great beyond the control by the rudder of a missile [ 2 , 4 , 5 ]. In addition, the development and bursting of asymmetric vortices were sensitive to the structure of the wings and the coupling position at high AoA [ 6 , [7] , [8] ]. During side-force and yawing, the controllability of the aircraft and missile was reduced, thereby resulting in a failed mission because the desired tracks of the fighter aircraft and missiles were changed.…”