Propulsion-Airframe Integration for Conceptual Redesign of a Low-Boom Supersonic Transport

A low-boom supersonic transport was designed for a cruise Mach of 1.7 and 40 passengers.
This low-boom aircraft, referred to as the Mach 1.7 40-PAX concept, was generated using
computational fluid dynamics (CFD) based sonic boom analysis at the start of overland cruise
(SOC). The engine for the Mach 1.7 40-PAX concept was designed using the Numerical
Propulsion System Simulation (NPSS) and modeled as a flow-through nacelle for CFD
analysis. To understand how the engine plume affects the undertrack ground signature, the
Mach 1.7 40-PAX concept is redesigned using an aeropropulsive CFD simulation. A process
is developed for approximation of the NPSS engine at SOC by a CFD engine for
aeropropulsive CFD simulation. The generated CFD engine has the identical nozzle boundary
conditions and approximately the same mass flow and thrust as those of the NPSS engine at
SOC. Then, the configuration with the CFD engines is optimized to approximately restore the
low-boom characteristics of the Mach 1.7 40-PAX concept. Finally, the CFD simulation data
for the optimized concept with the CFD engines is used to calibrate the low-fidelity
aerodynamic analyses for mission analysis of this concept. The cyclic dependency of the
involved disciplinary analyses is resolved using an iteration method for a consistent coupling
of the mission analysis, NPSS engine analysis, and low-boom redesign using the aeropropulsive
CFD simulation. This low-boom redesign study is used as an example to demonstrate how the
propulsion-airframe integration could be implemented for conceptual design of low-boom
supersonic transports.