Rapid Aerodynamic Optimization of Aerospace Structures: Engine Nacelles

Abstract

The geometric definition of the engine nacelle plays a pivotal role in determining the aerodynamic efficiency of different propulsion systems as it controls the capture area, mass flow rate and external drag. The primary objective of this paper is to provide design optimization for nacelles with reduced mathematical complexity, thereby ensuring reduced computational costs. This research employs a rapid aerodynamic evaluation using a fully integrated Python based framework which works at the intersection of Class Shape Transformation and a viscous-potential flow solver developed by the author which enables rapid topological transitions. The internal flow path is resolved with the compressible quasi one-dimensional continuity equation, while the external field is obtained from an incompressible potential formulation with isentropic post processing. The study shows that rapid, localized lip morphing can bound the design space before Navier-Stokes solvers are deployed. The paper also reports a solution verification study covering iterative and mesh convergence, states the Mach range over which the incompressible potential assumption holds, verifies each solver module against closed form solutions, and validates the surface pressure distribution against a Euler calculation on an identical geometry.