MULTI-DISCIPLINARY SUPERSONIC TRANSPORT DESIGN

A. Van dcr Velde*
Synaps Inc., Atlanta, GA, USA

17.1 Abstract

The challenge in the development of a very complex system like a supersonic transport is ти only to achieve the required technology, but also to link a team of highly skilled experts. In this paper a successful industrial approach is described to integrate the individual departments with their specific knowledge into the design of a future supersonic commercial transport.

Different designs arc analyzed with a modular synthesis model and compared on the basis of operating economy w ith specified performance and environmental impact. The analysis routines of the synthesis model are mainly configuration independent and represent fixed levels of structural, aerodynamic and propulsion technology. The specialist departments are responsi­ble for the content of the routines, and later verify the design with more refined methods. At present more than two hundred variables describe the aircraft geometry, engine characteristics and mission Thirty of those variables representing the aircraft and its flight-profile are opti­mized simultaneously as a function of Mach number, payload and range Because the various designs arc analyzed with the same routines and optimization procedures they can be easily compared. This aircraft pre-optimization results in a significant reduction of the number of fol­low-on detail-design cycles, especially for non-convcntional designs

Examples are given for the preliminary design of arrow-wing and oblique wing super­sonic aircraft as compared to subsonic aircraft using the same technology. It is also shown how technology and environmental constraints influence the sized design

17.2 List of Principal Symbols

engine bypass ratio Lift coefficient

design empty mass altitude

Indirect Operating Costs Mach number maximum takeoff weight

length

lift-to-drag ratio

oblique flying wing

oblique w ing body

reference wing area

Supersonic Civil Transport

specific fuel consumption (N’/hr/N)

sea level static

symmetric wing body

thickness to chord ratio

total operating cost per seat km

maximum turbine entry temperature

minimum control speed

width

Greek Letters:

maximum engine pressure ratio

sweep angle ozone depletion

sonic boom sea-level overpressure

17.3 Introduction

In the early days of aviation, the technology to design aircraft was relatively simple and the re­quirements on product safety minima). As a consequence, aircraft could be designed by small groups of people. Such small groups can communicate directly and therefore work very efficient­ly. For instance – In 1936 it look Kurt Tank exactly one year to conceive and produce the Focke Wulf Condor, the first transatlantic airliner. However as the technology became more complex, aircraft designers had to specialize to cope w ith the increased flow of information In addition, the growing market required improved safety and accurate performance guarantees. Such per­formance and safety guarantees could only be made by extensive analysis and testing of the air­craft design. Due to this increased work-load an aircraft is no longer designed by a single group, but by hundreds of specialists in many departments. This subdivision of work further increased productivity and enabled the development of the complicated but safe transport aircraft we have today.

Although the specialists can fit the aircraft with the best technology available in their field, it is unclear whether this will always lead to the best aircraft The best aircraft can only be designed with a truly interdisciplinary effort. The number of people and independent locations increases the design cycle time and decreases the amount of interaction between the disciplinary groups. Progress is thereby limited to incremental improvements making it difficult to achieve the breakthroughs in aircraft design still common thirty years ago. This paper will present a solution to this problem that was based on the author’s thesis at Stanford University (371 j.