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The objective of this paper is to illustrate the methods and tools developed to size and synthesize a stopped rotor/wing vehicle using a reaction drive system, including how this design capability is incorporated into a sizing and synthesis tool, VASCOMP II. This new capability is used to design a vehicle capable of performing a V-22 escort mission, and a sized vehicle description with performance characteristics is presented. The resulting vehicle is then compared side-by-side to a variable diameter tiltrotor designed for the same mission. Results of this analysis indicate that the reaction-driven rotor concept holds promise relative to alternative concepts, but that the variable diameter tiltrotor has several inherent performance advantages. Additionally, the stopped rotor/wing needs considerably more development to reach maturity.

The projection of aeroelastic constraints in the design space has long been a want in the design process of vehicles. These properties are usually not established accurately until later phases of design. The desire is to bring another interactive constraint to the conceptual design phase and allow the designer to see the impact of design decisions on aeroelastic characteristics. Even though a number of analysis and optimization tools have been developed to support aeroelastic analysis and optimization in the flight vehicle design process, the toolbox is far from being complete. The results often cannot be obtained in a manner timely enough and the natural division of the engineering team into specialty groups is not supported very well by the aerodynamic-structures monolithic codes typically in the above toolbox. The monolithic codes are also not amenable to the use of concurrent processing now made available by computer technology.

One of the major impetuses for the development of modern, robust design methodologies is the need for affordable aerospace systems. Because the affordability of a system is directly tied to the economics of developing, manufacturing, operating, and disposing of that system, it has become common practice to perform an economic analysis of a potential system to evaluate its viability. Additionally, as needs for improved modeling, analysis, and evaluation capability have arisen, several techniques which have proved themselves popular in economics have been adopted. While adopting these techniques has improved the capabilities of the designer/engineer, they do not proceed far enough. That is aerospace systems design, and consequently all complex systems design, could actually be considered an exercise in economics. All of the players, i.e. designers, firms, end users, and the systems themselves can be considered microeconomic entities.

In today’s emerging parametric and probabilistic design environments, disciplinary or multidisciplinary analysis data are represented efficiently with the use of metamodels. Each metamodel is an efficient replacement for a particular design analysis tool. An object oriented library is developed in this paper to represent vehicle configuration in a generic manner and assist the analysis data collection for the metamodeling process. The library is used to produce input files for design analysis tools. It can also be used to create preprocessors for integration environments used in the design process. This allows for smoother integrations of analysis programs within such environments as the environment now needs only replace data in one central input file rather than a file for each analysis tool.

Market forecasts predict a potentially large market for a Quiet Supersonic Business Jet provided that several technical hurdles are overcome prior to fielding such a vehicle. In order to be economically viable, the QSJ must be able to fly at supersonic speeds overland and operate from regional airports in addition to meeting government noise and emission requirements. As a result of these conflicting constraints on the design, the process of selecting a configuration for low sonic boom is a difficult one. Response Surface Methodology along with physics-based analysis tools were used to create an environment in which the sonic boom can be studied as a function of design and mission parameters. Ten disciplinary codes were linked with a sizing and synthesis code by using a commercial wrapper in order to calculate the required responses with the desired level of fidelity.

The desire of achieving faster cruise speed for rotorcraft vehicles has been around since the inception of the helicopter. Many unconventional concepts have been considered and researched such as the advanced tilt rotor with canards, the tilt-wing, the folding tiltrotor, the coaxial propfan/folding tiltrotor, the variable diameter tiltrotor, and the stopped rotor/wing concept, in order to fulfill this goal. The most notable program which addressed the technology challenges of accomplishing a high speed civil transport mission is the High Speed Rotorcraft Concept (HSRC) program. Among the long list of potential configurations to fulfill the HSRC intended mission, the stopped rotor/wing is the least investigated due to the fact that the existing rotorcraft synthesis codes cannot handle this type of vehicle. In order to develop such a tool, a designer must understand the physics behind this unique concept.

In today’s aircraft design, more and more attention is paid to the conceptual and preliminary design stages in order to increase the capability of choosing a design that will be successful. Therefore, the decisions made during these design phases play a central role in determining the success of a design. Decision making techniques at these stages, must manage multiple, conflicting criteria and capture associated uncertainties. The method presented in this study was developed from Joint Probability Decision Making (JPDM), a probabilistic multiple criteria decision making technique. The proposed method eliminated the limitations that JPDM has by utilizing Utility Functions to represent the decision maker’s preference. An advanced rotorcraft concept selection problem is performed in order to demonstrate the improvements, and the results obtained from the proposed method and the JPDM technique are compared with each other.

A design process is formulated and implemented for the taxonomy selection and system-level optimization of an Efficient Multi-Mach Aircraft Current Technology Concept and an Advanced Concept. Concept space exploration of taxonomy alternatives is performed with multi-objective genetic algorithms and a Powell’s method scheme for vehicle optimization in a multidisciplinary modeling and simulation environment. A dynamic sensitivity visualization analysis tool is generated for the Advanced Concept with response surface equations.

Traditional historical-data based design processes are clearly inappropriate for morphing vehicles. There are no historical data for these type of configurations, the appropriate mission for this class of vehicles is unknown, and there are many unique aspects of a morphing vehicle that are dependent on the specific concept chosen. The design process proposed in this paper attempts to account for these difficulties in a flexible and transparent manner while leveraging existing tools and processes wherever possible.

A Hypersonic Strike Fighter (HSF) would provide many benefits over current fighters, including increased effectiveness and survivability. However, there are many design challenges to developing such a vehicle. Therefore the conceptual design of an HSF requires the development of new tools and methods to analyze and select vehicle concepts. A parametric method was developed to determine aerodynamic characteristics of hypersonic vehicles in a rapid, automated way. This parametric method and other tools were then used to select a baseline design and optimize this baseline for the notional mission.

The desire to facilitate the conceptual and preliminary design of hypersonic cruise vehicles has created the need for simple, fast, versatile, and trusted aerodynamic analysis tools. Metamodels representing physics-based engineering codes provide instantaneous access to calibrated tools. Nonlinear transformations extend the capability of metamodels to accurately represent a large design space. Independence, superposition, and scaling properties of the hypersonic engineering method afford an expansive design space without traditional compounding penalties. This one-time investment results in aerodynamic and volumetric metamodels of superior quality and versatility which may be used in many forms throughout early design. As a module, they can be an integral component within a multidisciplinary analysis and optimization package. Aerodynamic polars they produce may provide performance information for mission analysis.

The Conceptual Aerospace Systems Design and Analysis Toolkit (CASDAT) provides a baseline assessment capability for the Air Force Research Laboratory. The historical development of CASDAT is of benefit to the design research community because considerable effort was expended in the classification of the analysis tools. Its implementation proves to also be of importance because of the definition of assessment use cases. As a result, CASDAT is compatible with accepted analysis tools and can be used with state-of-the-art assessment methods, including technology forecasting and probabilistic design.