Thresholds and influencing factors on vortex bursting of an ogive-cylinder body-delta wing: an experimental and numerical approach

Abstract Despite the exceptional aerodynamic performance of delta wing-body configurations, the phenomenon of vortex bursting and its influencing factors remain inadequately understood. This research investigates the effects of Mach number, Reynolds number, and body upwash on the angle of attack and location of vortex bursting over a delta wing-body planform within subsonic and transonic flight regimes. Experimental and computational methodologies were employed. Aerodynamic forces and moments were measured using a six-component internal balance in the ASSEF Transonic Wind Tunnel (ATWT), while surface static pressure measurements were acquired with electronically scanned pressure (ESP) modules. The experimental results aligned with previous studies, validating the experimental setup. Numerical simulations were corroborated by experimental surface pressure, force, and moment data. The study initially examines the burst angle of attack, revealing a rise from 12° to 13° as the Mach number increases from 0.3 to 0.9. However, at Mach 0.95, vortex bursting did not occur up to an angle of attack of 15°, indicating a threshold in the transonic regime beyond which vortex bursting is absent at moderate angles of attack. Furthermore, a decrease in Reynolds number leads to a lower burst angle of attack, and the presence of a body significantly reduces this angle compared to wing-only configurations. The study also explores the burst position, observing a nonlinear shift with increasing Mach number. A threshold of 14° for the angle of attack was identified, where further increases in Reynolds number alter the burst position both longitudinally and laterally. The newly identified thresholds provide valuable insights for optimizing the design and improving the understanding of vortex bursting in similar configurations.