Consistent Coupling of Aeropropulsive and Engine Performance Analyses for Low-Boom Supersonic Aircraft Conceptual Design

This paper presents a process for a consistent coupling of aeropropulsive and engine performance analyses for conceptual design of low-boom supersonic aircraft. An inviscid computational fluid dynamics (CFD) solver is used for aeropropulsive analysis. A variable cycle engine (VCE) model and a low-boom supersonic aircraft are selected to demonstrate the coupling process. The main technical contribution is a block coordinate optimization method to generate an axisymmetric, external-compression, supersonic inlet for a cruise Mach of 1.8, with a total pressure recovery of 97.2%, that has the same aerodynamic interface plane shape and approximately the same mass flow rate as the VCE model at start of cruise (SOC). A numerical optimization of the nozzle shape is also performed to generate a CFD engine that emulates the VCE at SOC, achieving a consistent coupling of aeropropulsive and engine performance analyses for conceptual low-boom design. Off-body pressures and undertrack sonic boom ground signature of the aircraft with two CFD engines are compared to those of the same aircraft with two flow-through nacelles. The documented results illustrate that the aeropropulsive simulation has a significant influence on near-field pressure calculation, but less so on the overall shape of the undertrack sonic boom ground signature.