Optimizing the design of a supersonic Planar Dual Bell Nozzle (PDBN)

Abstract

Dual bell nozzles present a promising solution for maximizing propulsion efficiency at high altitudes, while also mitigating dangerous side loads at lower altitudes. Such nozzles are comprised of two distinct contours, with the first optimized for low altitude operation, and the second tailored for high altitude conditions. These contours are interconnected at an inflexion point. The present study focuses on optimizing the contour design of a planar dual bell nozzle. Leveraging the commercial ANSYS-Fluent software, we conducted an investigation into the influence of the inflection angle on the transition between the two operating modes, examined the flow behavior inside the nozzle, and assessed the impact of the inflection angle on the thrust coefficient.