Aerodynamic Shaping of Spherical Turrets to Mitigate AeroOptic Effects

摘要

Hemispherical turrets provide an efficient means of mounting an optical system on an aircraft, but are susceptible to the formation of flows, such as shocks and separated shear layers that are known to present a severe optical aberration to the outgoing beam. In this paper, methods are presented to prevent or mitigate the formation of these aero-optic flows using improved aerodynamic shaping of the turret itself. The investigation focuses on the use of the "virtual duct" approach, which has been shown previously to successfully prevent aero-optic flows on an underwing pod up to freestream Mach numbers over 0.8. Computational fluid dynamic results are presented to demonstrate the effectiveness of the virtual duct approach, as well as other mitigation strategies.