Sub- and Transonic Vortex Breakdown Flight Condition Simulations of the F-16XL Aircraft

Abstract

Free-flight Navier–Stokes simulations of the Cranked Arrow Wing Aerodynamics Project International F-16XL aircraft were performed to probe for the complex vortex flowfield structures at high angle of attack close to and beyond vortex breakdown conditions. The scope of the paper probes for the quality and quantity of high-resolution numerical simulations possible with the current computer capacity at free-flight Reynolds numbers. It provides an insight into the effect of turbulence modeling of these complicated flows; the free-flight measured pressure distributions are compared with solutions achieved with the one-equation Spalart–Allmaras turbulence model, the one-equation Spalart–Allmaras turbulence model with rotation correct, the model, and the turbulence model with scale-adaptive simulation. The third topic of the investigation is the complexity of the vortex flow system of the configuration at sub- and transonic speeds at vortex breakdown conditions. For this purpose, the details of the different vortex systems and their behavior are prepared and discussed.