Subsonic Versus Supersonic Business Jets Full Concept Comparison Considering Technical Environmental And Economic Aspects

Inhaltsangabe:Introduction: On the 26th of August 2010 the new ultra-large-cabin ultra-long-range Gulfstream G650 business jet reached Mach 0.995 during its flight test campaign (1). This is almost the speed of sound (Mach 1) and inspires one to say, why not fly faster than the speed of sound! Reduce travelling time in the commercial business aviation segment. This is, however not a completely new vision. Many companies and research facilities have already spent a lot of time and investment in studies to investigate the feasibility of supersonic flight. Entry Into Service (EIS) for the new Gulfstream G650 is scheduled for 2012. In the following the main performance parameter of the G650 aircraft will be summarised. The parameters range, cruise speed, MTOW, etc. have been selected and serve as a basis to allow an appropriate comparison between the G650 as the latest high end Subsonic Business Jet and potential in future Supersonic Business Jets (SSBJ) within this subject Master Thesis. With the impressive maximum range of nearly 13,000 km the G650 can connect Dubai with New York or London with Buenos Aires within almost 14 hours. Maximum Range @ Normal Cruise Speed: 7,000 nm/12,964 km. Normal Cruise Speed Mach: 0.85/904 km/h. Mmo (Maximum Operating Mach Number): Mach 0.925. Maximum Cruise Altitude: 51,000 ft/15,545 m. Maximum Takeoff Weight (MTOW): 99,600 lb/45,178 kg. Maximum Fuel Weight: 44,200 lb/20,049 kg. Passengers: 11 18. Price: appr. 60-70 million USD. Gulfstream business rival Bombardier Aerospace also announced in October 2010 two new high end models, the Global 7000 and 8000 with a maximum range of 7,300 nm (13,520 km) and 7,900 nm (14,631 km) at cruise speed Mach 0.85. Entry Into Service is scheduled for 2016 (Global 7000) and 2017 (Global 8000). A comprehensive overview of business jets in service and in development is given in attachment 13.1. A Supersonic Business Jet flying at Mach 2 cruise speed could virtually halve the travelling time, which would enormously enhance the mobility and flexibility. In order to achieve this ambition a paradigm shift is required. New technologies must be established, the impact on the environment must be understood and minimised, existing regulations must be changed to permit overland flight restrictions and the product still needs to be economically viable. All of the above aspects must be considered and will be subject for discussion within this Master Thesis (See also figure [...]

High-speed flight is a major technological challenge for both commercial and business aviation. As a first step in revitalizing efforts by the National Aeronautics and Space Administration (NASA) to achieve the technology objective of high-speed air travel, NASA requested the National Research Council (NRC) to conduct a study that would identify approaches for achieving breakthroughs in research and technology for commercial supersonic aircraft. Commercial Supersonic Technology documents the results of that effort. This report describes technical areas where ongoing work should be continued and new focused research initiated to enable operational deployment of an environmentally acceptable, economically viable commercial aircraft capable of sustained supersonic flight, including flight over land, at speeds up to approximately Mach 2 in the next 25 years or less.

The Preliminary Aircraft Design and Optimisation tool, PrADO, is an in-house program of the Institute of Aircraft Design and Lightweight Structures, TU Braunschweig, Germany, which covers a wide range of aspects of aircraft preliminary design. An initial aircraft concept serves as a basis for various analysis modules. Each module is designated to fulfil one special task e.g. aerodynamic analysis, estimation of structural mass, etc. The available methods grouped within those modules range from statistical methods to physics based models. From an aircraft developer’s point of view PrADO is used within both, the conceptual and the preliminary design phase. The aim of this thesis is to introduce methods and methodologies to aircraft conceptual and preliminary design, more precisely to PrADO, that allow to judge supersonic aircraft concepts. Therefore, the aerodynamic analysis module, the structural analysis module and the propulsion module are extended. An inviscid flow solver is integrated to obtain aerodynamic coefficients. The calculated data serves as input to other analysis modules of PrADO. While the aerodynamic analysis module solely uses the outer geometry of the aircraft, the structural analysis module uses its internal structural layout as additional input to a herein developed finite element model generator. The distribution of secondary mass, fuel loading and payload distributions as well as loads for ground cases and trimmed flight cases are taken from the PrADO database, whereas the aerodynamic forces are calculated by solving the inviscid Euler equations. The model serves as basis for structural sizing and consequently the estimation of structural mass. The purpose of the propulsion module is to size the engine, to calculate the engine performance map and to provide reliable mass data based on the thermodynamic cycle. PrADO provides various models for the analysis of turbojet, turbofan and turboprop engines. It is extended by a turbofan engine with mixed exhaust flow. The verification of the aerodynamic data is solely based on its expected qualitative distribution, since data from higher order methods was not available for the time being. The results compare well with the expected behaviour. The structural sizing process is verified based on an example from literature. The results of the developed sizing algorithm show extraordinary agreement with the reference data. The extended aircraft design process is finally applied to an aircraft from the European research project HISAC. The results compare well with global aircraft data. An excursion into the field of temperature effects in supersonic flight is provided, since no relevant literature is found on the topic with regard to conceptual and preliminary aircraft design. The results are translated into helpful information on the material selection process in the stage of aircraft pre-design. Eventually, the tool chain is applied to analyse a supersonic business jet and the results are presented. Based on the results of this basic design, a parameter study is conducted. A combination of cruise Mach number and design range is varied. Global design parameters show expected sensitivity to such variations. Das am Institut für Flugzeugbau und Leichtbau der TU Braunschweig entwickelte Programm PrADO (Preliminary Aircraft Design and Optimisation tool) stellt Werkzeuge zur Analyse und Beurteilung von Flugzeugen in der Konzept- und Vorentwurfsphase bereit. Basis der Analyse ist ein erstes Flugzeugkonzept. Jedes Entwurfsmodul gruppiert Methoden zur Lösung einer Teilaufgabe im Vorentwurfsprozess, z.B. Bestimmung der aerodynamischen Beiwerte oder Masseanalyse. Die vorhandenen Methoden reichen von einfachen Abschätzungsformeln bis hin zu physikalisch begründeten Berechnungsmodellen. Die Zielsetzung dieser Arbeit ist es, Methoden in die Konzept- und Vorentwurfsphase, genauer in das Programm PrADO, einzuführen, welche die Bewertung von Überschallflugzeugen ermöglichen. Daher werden die aerodynamischen, strukturmechanischen und antriebsspezifischen Entwurfsmodule erweitert. Zur Berechnung der aerodynamischen Beiwerte wird ein Euler-Verfahren eingesetzt. Die Ergebnisse stehen anderen Entwurfsmodulen in Form von Kennfeldern zur Verfügung. Das strukturmechanische Modell benötigt, neben der äußeren Geometrie, auch den inneren Aufbau des Flugzeugs. Diese Daten bilden die Grundlage eines Finite-Elemente-Modells. Die Verteilung von Sekundärmassen, Kraftstoff und Nutzlast, sowie Lasten für Boden- und ausgetrimmte Flugfälle werden der PrADO-Datenbank entnommen. Die aerodynamischen Kräfte werden mit dem Euler-Verfahren berechnet und auf das Modell aufgeprägt. Das Modell bildet die Basis zur Strukturdimensionierung und somit der Berechnung der Strukturmasse. Die Aufgabe des Antriebsmoduls ist die Triebwerksgröße zu bestimmen, Triebwerkskennfelder bereitzustellen und die Masse des Antriebssystems zu berechnen. Das Modul wird um ein Zweikreis-Turbinenluftstrahltriebwerk mit Mischung von Primär- und Sekundärstrom ergänzt. Die qualitativen Verläufe der aerodynamischen Beiwerte entsprechen dem zu erwartenden Verhalten. Für einen quantitativen Vergleich stehen keine Vergleichsdaten aus höherwertigen Verfahren zur Verfügung. Das erweiterte Strukturanalysemodul wird auf ein Literaturbeispiel angewendet. Die Ergebnisse zeigen eine sehr gute Übereinstimmung mit den Daten. Nach der Verifikation der Einzelmodule wird der Gesamtentwurfsprozess an einem Flugzeug des europäischen Projekts HISAC überprüft. Die globalen Entwurfsergebnisse zeigen sehr gute Übereinstimmungen mit den verfügbaren Referenzdaten. Die im Überschallflug auftretenden thermischen Aspekte werden in einem kurzen Exkurs behandelt. Dies erscheint notwendig, da zu diesem Thema keine, auf den Vorentwurf bezogene Literatur gefunden wurde. Die Ergebnisse geben dem Ingenieur erste Hinweise zur Materialauswahl im Rahmen der Konzept- und Vorentwurfsphase. Schlussendlich wird der erweiterte Entwurfsprozess zum Entwurf eines Überschallgeschäftsreiseflugzeugs genutzt. Auf Basis der gewonnenen Erkenntnisse wird eine Parameterstudie durchgeführt. Die Sensitivitäten der globalen Entwurfsparameter bei Änderungen von Machzahl und Reichweite werden gut wiedergegeben.