Aero-Propulso-Elastic Analysis of a Supersonic Transport

Abstract

An aeroelastic modeling capability of a flexible aircraft with gas turbine engines is developed using a computational fluid dynamics tool as an integration platform. The new modeling capability allows for the typical aeroelastic analysis to include a nonlinear dynamic model of the turbomachinery that is capable of capturing relevant gas dynamics. An example case of the aero-propulso-elastic (APE) modeling capability is explored for a supersonic transport vehicle with turbofan engines. An overview of the methodology for integrating the propulsion system and elastic vehicle is provided. This is followed by a study to explore coupling sensitivities compared against typical aeroelastic analysis. Dynamic and static vehicle responses are considered across key flight conditions and vehicle-level angles of attack, where the inclusion of the propulsion system has a 10% increase in vehicle wing tip deformations. It is found that the propulsion system is stable at various operating conditions, with structural oscillations having little impact on propulsion system performance. Perceived loudness, a key performance metric for a supersonic transport, is investigated using the APE model. Results lead to an approximately 4 dB increase in noise over a rigid body analysis that neglects the propulsion system. The greatest impacts are shown during off-nominal conditions.

Conceptual design and integration of a propulsion system for a supersonic transport aircraft

“…The diameter of the engine is significant at 4.27 m. Suppose this engine is to be placed in underwing pods, in that case, this will result in a very large undercarriage or require a high wing on the fuselage similar to the conceptual Lockheed Martin N + 2 commercial supersonic transport vehicle. 22 Alternate engine placement options on the aircraft should be investigated, such as the above-wing configuration. Unfortunately, for that option, research by Volkov and Mazhul 23 has found a significant increase in sonic boom from an above-wing placement.…”

“…Finally, the placement of the engine onto the airframe will need to be determined, noting its size. Then, a CFD analysis should be completed to investigate how airflow interacts with the engine and aircraft interface and aeroelasticity such as that by Connolly, Kopasakis, 22 with a focus on stabilising inlet flows through appropriate inlet control like that researched by Chen, Zhang. 35…”

Conceptual aerodynamic design of an executive supersonic passenger aircraft – ESPA

“…Other significant examples emerging for supersonic aircraft include aerodynamic optimization of three-dimensional natural laminar flow wings, 25 aeroelastic suppression to reduce aircraft weight, 12,15 aeroelastic effects on the sonic boom 13 and even engine aeroelastic effects. 16 Such multidisciplinary optimization offer considerably better estimates of, and refinement of, the sonic boom while refining the aerodynamic shape and aeroelastic properties of a wing structure.…”

“…9 However, the penetration of smaller supersonic transports opens a niche to the hegemony of subsonic passenger aircraft. 3,5,8 This niche is spawning renewed research, particular into methodologies for design like multidisciplinary optimization, 11–16 sonic boom minimization, 17–19 aerothermal heating, 20 carbon emissions 8 and numerical augmentation of supersonic wind tunnel testing. 21…”

“…9 However, the penetration of smaller supersonic transports opens a niche to the hegemony of subsonic passenger aircraft. 3,5,8 This niche is spawning renewed research, particular into methodologies for design like multidisciplinary optimization, [11][12][13][14][15][16] sonic boom minimization, [17][18][19] aerothermal heating, 20 carbon emissions 8 and numerical augmentation of supersonic wind tunnel testing. 21 One research question not being asked sufficiently is in how fast and how large the next supersonic passenger aircraft should be after the three new business jets?…”