Organizational Unit:

Aerospace Systems Design Laboratory (ASDL)

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https://hdl.handle.net/1853/70744

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Organizational Unit

Daniel Guggenheim School of Aerospace Engineering

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https://finding-aids.library.gatech.edu/agents/corporate_entities/1135

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Publication Search Results

Now showing 1 - 10 of 13

Formulation of an IPPD Methodology for the Design of a Supersonic Business Jet

(Georgia Institute of Technology, 1996-10) Mavris, Dimitri N. ; Hayden, William T.

The growth of international markets as well as business partnerships between U.S. and Asian-based firms has lead to an increased interest in an economically viable business jet capable of supersonic cruise and trans-Pacific range with one stop over (or non-stop trans-Atlantic range) 1 . Such an aircraft would reduce the travel time to these regions by as much as 50% by increasing cruise Mach number from roughly 0.85 to 2.0. In response to this interest, the 1996 AIAA / United Technologies / Pratt and Whitney Individual Undergraduate Design Competition has issued a Request for Proposal for the conceptual design of a supersonic cruise business jet. The design of this aircraft considered both performance and economic issues in the conceptual design phase. Through the use of Response Surface Methodology (RSM) and Design of Experiments (DoE) techniques, the aerodynamics of this vehicle were modeled and incorporated into an aircraft sizing code, FLOPS. This program was then combined with an aircraft life-cycle cost routine, ALCCA, and response surfaces were created for the optimization of an Overall Evaluation Criterion (OEC) which considered both mission capability (i.e. payload, range, OEW) and affordability issues (i.e. life cycle cost, acquisition cost). The OEC for this study and was determined through a Quality Function Deployment analysis considering both the voice of the customer and the voice of the engineer. Using a Robust Design Simulation (RDS) approach, an economic uncertainty analysis was performed to optimize the aircraft (i.e. maximize the OEC) while minimizing the sensitivity of these parameters to fluctuations in variables over which the designer has no control (i.e. fuel cost, number of vehicles produced, etc.). The result is an aircraft which can cruise at Mach 2.0 for 3160 nm (satisfying all mission range requirements), weighs 60314 lb, has a balanced field length of less than 7000 ft, and has a mean acquisition cost of $37.523 million in 1992 dollars.
An Assessment of Reaction Driven Stopped Rotor/Wing Using Circulation Control in Forward Flight

(Georgia Institute of Technology, 1996-10) Tai, Jimmy C. M. ; Mavris, Dimitri N. ; Schrage, Daniel P.

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. The uniqueness of stopped rotor/wing vehicles that use reaction drive can be found in the tight coupling that is present between the rotor and the engine which in turn requires these subsystems to be sized concurrently rather than in isolation. A methodology and simulation tool capable of handling this coupling is under development at the Aerospace Systems Design Laboratory (ASDL) at Georgia Institute of Technology. The development of a new design tool (TJCC) and the use of a statistical technique called Response Surface Methodology linked into the V/STOL Aircraft Sizing and Performance Computer Program (VASCOMP II) has provided the capability of sizing stopped rotor/wings. The potential success of a stopped rotor/wing configuration can only be determined through direct performance comparisons with other high speed rotorcraft concepts using analytical methods of comparable sophistication. The authors have previously presented limited results from this study detailing the rotor/wing performance during hover. In this paper the forward flight regime for both the helicopter and fixed wing modes are discussed. Representative results presented include performance characteristics such as the horsepower required curves versus forward flight for both the rotorcraft and fixed wing modes of operation. Furthermore, the mass flow requirements, and transition performance associated with this aircraft are also examined in this paper.
Preliminary Assessment of the Economic Viability of a Family of Very Large Transport Configurations

(Georgia Institute of Technology, 1996-10) Mavris, Dimitri N. ; Kirby, Michelle Rene

A family of Very Large Transport (VLT) concepts were studied as an implementation of the affordability aspects of the Robust Design Simulation (RDS) methodology which is based on the Integrated Product and Process Development (IPPD) initiative that is sweeping through industry. The VLT is envisioned to be a high capacity (600 to 1000 passengers), long range (~7500 nm), subsonic transport. Various configurations with different levels of technology were compared, based on affordability issues, to a Boeing 747-400 which is a current high capacity, long range transport. The varying technology levels prompted a need for an integration of a sizing/synthesis (FLOPS) code with an economics package (ALCCA). The integration enables a direct evaluation of the added technology on a configuration economic viability. The determination of the viability was based on the assessment of the following evaluation criteria: average yield per Revenue Passenger Mile ($/RPM), Total Operating Cost per day (TOC), acquisition cost, airframe manufacturer's cash flow, and airline? return on investment. The assessment of these criteria was performed through the application of several statistical techniques such as Response Surface Methodology (RSM), Design of Experiments (DoE), and Monte Carlo Simulations. The result is a series of second-order equations that model the evaluation criteria above stated. The final conclusion of this analysis is that the 800 passenger configuration would meet most of the market demand (600 to 1600 passengers) of 250 city pairs considered. This paper reviews the RDS methodology and how it was applied to determine the economic viability of a VLT concept. In addition, it documents the results of the method used to determine the economic viability of a family of VLT configurations and the most affordable VLT configuration for a specified market demand.
Application of a New Economic Analysis Tool to a Two-Stage-to-Orbit RBCC Launch Vehicle Design

(Georgia Institute of Technology, 1996-09) Olds, John R. ; Lee, Hosung

As aerospace industries are forced to compete in an environment of declining federal budgets and increased competition, 'design for performance' is quickly giving way to 'design for cost.' Many modern launch vehicle programs are initiated with the goal of lowering the cost of delivering payloads to orbit while limiting investment costs and yielding a reasonable rate of return. Designers of new vehicles will need tools to quickly evaluate not only the costs, but also the revenue potential of various design options. To provide information that can be used to drive design decisions or an optimization process, these economic analysis tools must be fully integrated into the design environment. This paper reports the status of research to create a design-oriented economic analysis tool for conceptual launch vehicle design (called CAM). An overview of each CAM component is presented -- program definition, non-recurring costs, recurring costs, market evaluation, and revenue. As a demonstration, CAM is used to optimize the end-customer launch prices to four individual launch markets for a multi-market capable two-stage-to-orbit launch system. The vehicle utilizes rocket-based combined-cycle engines on the booster state and has two interchangeable rocket upper stages (one for GTO missions and one for LEO missions). Business-oriented results such as rate of return, and sensitivities to government investment, airframe life, and operations costs are presented.
Techniques for Integrating Computer Programs into Design Architectures

(Georgia Institute of Technology, 1996-09) Hale, Mark A. ; Craig, James I.

The benefits of using modular computer architectures for multi-disciplinary design are being explored by industry, government, and academia. These architectures are being validated through a considerable number of in-house and team demonstration projects. Based on experiences to date, a generic computing design architecture consists of the following components: process management, a common product data model, an analysis toolkit, a problem-independent computing backplane, and integration mechanisms. The latter is concerned with the addition of services to computer resources in an analysis toolkit, called wrapping, and is discussed in this paper. Wrapping allows for the collaborative use of resources within a computer architecture. Strategies and consequences of integrating resources from executables to source code are outlined. Benefits associated with using software agents to assist designers in integrating and using software resources in design computing architectures are highlighted.
Reduced Order Guidance Methods and Probabilistic Techniques in Addressing Mission Uncertainty

(Georgia Institute of Technology, 1996-09) DeLaurentis, Daniel A. ; Mavris, Dimitri N. ; Calise, Anthony J. ; Schrage, Daniel P.

Recognizing that vehicle synthesis fulfills the role of integrator of the mutually interacting disciplines, difficulties persist in intelligently implementing disciplinary analysis into this synthesis process. This paper develops and describes analytical and statistical approximation techniques used to create design-oriented analyses which are implementable in the process. Specifically, techniques related to the vehicle guidance discipline are examined. The ultimate goal is to investigate the economic viability of an aerospace system in the face of uncertainty at the system and discipline design levels. The notion of a requirement is replaced by a modeling of mission variability, since future aircraft will likely fly a variety of missions. Aircraft guidance laws are key components in the mission analysis portion of an aircraft sizing code, and thus they must be included in the investigation. Through the use of statistical modeling techniques, a link between mission uncertainty, optimal guidance, wing planform, and economic objectives is obtained. This linkage allows for the investigation of guidance and mission effects on such quantities as gross weight and ticket price (on a per mile basis). Further, the resulting solutions are robust since they are obtained by choosing control parameters which maximize the probability of meeting a target while simultaneously assuring that appropriate constraints (which are also probabilistic) are met.
System Synthesis in Preliminary Aircraft Design Using Statistical Methods

(Georgia Institute of Technology, 1996-09) DeLaurentis, Daniel A. ; Mavris, Dimitri N. ; Schrage, Daniel P.

This paper documents an approach to conceptual and early preliminary aircraft design in which system synthesis is achieved using statistical methods, specifically Design of Experiments (DOE) and Response Surface Methodology (RSM). These methods are employed in order to more efficiently search the design space for optimum configurations. In particular, a methodology incorporating three uses of these techniques is presented. First, response surface equations are formed which represent aerodynamic analyses, in the form of regression polynomials, which are more sophisticated than generally available in early design stages. Next, a regression equation for an Overall Evaluation Criterion is constructed for the purpose of constrained optimization at the system level. This optimization, though achieved in a innovative way, is still traditional in that it is a point design solution. The methodology put forward here remedies this by introducing uncertainty into the problem, resulting in solutions which are probabilistic in nature. DOE/RSM is used for the third time in this setting. The process is demonstrated through a detailed aero-propulsion optimization of a High Speed Civil Transport. Fundamental goals of the methodology, then, are to introduce higher fidelity disciplinary analyses to the conceptual aircraft synthesis and provide a roadmap for transitioning from point solutions to probabilistic designs (and eventually robust ones).
A New Approach to Integrated Wing Design in Conceptual Synthesis and Optimization

(Georgia Institute of Technology, 1996-09) DeLaurentis, Daniel A. ; Cesnik, Carlos Eduardo Stolf ; Lee, Jae-Moon ; Mavris, Dimitri N. ; Schrage, Daniel P.

Design-oriented analysis has become increasingly important as more and more problems traditionally solved in isolation are being approached from a multidisciplinary point of view. One such problem is the aeroelastic optimization of supersonic transport wings. Whereas simplified analytical techniques may not be sophisticated enough, and complex numerical models may be too cumbersome, this paper puts forward a new approach to achieving a balance between modeling fidelity and required accuracy. Higher fidelity analysis techniques, usually associated with design stages where key geometric variables have been fixed, are used to model a design space consisting of these important geometric variables. This is accomplished through the combined use of a Design of Experiment/Response Surface Method technique and parametric analysis tools (including an automated finite element grid generation procedure). The result is a prediction method for the structural weight of an aeroelastically optimized wing for use in an Integrated Product and Process Development environment, where cost, performance, and manufacturing trades can be accomplished. The technique is to be demonstrated on the aeroelastic design of a wing for a generic High Speed Civil Transport, based on a select set of planform and airfoil design variables. Finally, a framework for evaluating new technologies within the aeroelastic optimization is outlined.
Application of Probabilistic Methods for the Determination of an Economically Robust HSCT Configuration

(Georgia Institute of Technology, 1996-09) Mavris, Dimitri N. ; Bandte, Oliver ; Schrage, Daniel P.

This paper outlines an approach for the determination of economically viable robust design solutions using the High Speed Civil Transport (HSCT) as a case study. Furthermore, the paper states the advantages of a probability based aircraft design over the traditional point design approach. It also proposes a new methodology called Robust Design Simulation (RDS) which treats customer satisfaction as the ultimate design objective. RDS is based on a probabilistic approach to aerospace systems design, which views the chosen objective as a distribution function introduced by so called noise or uncertainty variables. Since the designer has no control over these variables, a variability distribution is defined for each one of them. The cumulative effect of all these distributions causes the overall variability of the objective function. For cases where the selected objective function depends heavily on these noise variables, it may be desirable to obtain a design solution that minimizes this dependence. The paper outlines a step by step approach on how to achieve such a solution for the HSCT case study and introduces an evaluation criterion which guarantees the highest customer satisfaction. This customer satisfaction is expressed by the probability of achieving objective function values less than a desired target value.
Options for Flight Testing Rocket-Based Combined-Cycle (RBCC) Engines

(Georgia Institute of Technology, 1996-07) Olds, John R.

While NASA's current next-generation launch vehicle research has largely focused on advanced all-rocket single-stage-to-orbit vehicles (i.e. the X-33 and it¹s RLV operational follow-on), some attention is being given to advanced propulsion concepts suitable for "next-generation-and-a-half" vehicles. Rocket-based combined-cycle (RBCC) engines combining rocket and airbreathing elements are one candidate concept. Preliminary RBCC engine development was undertaken by the United States in the 1960's. However, additional ground and flight research is required to bring the engine to technological maturity. This paper presents two options for flight testing early versions of the RBCC ejector scramjet engine. The first option mounts a single RBCC engine module to the X-34 air-launched technology testbed for test flights up to about Mach 6.4. The second option links RBCC engine testing to the simultaneous development of a small-payload (220 lb.) two-stage-to-orbit operational vehicle in the Bantam payload class. This launcher/testbed concept has been dubbed the W vehicle. The W vehicle can also serve as an early ejector ramjet RBCC launcher (albeit at a lower payload). To complement current RBCC ground testing efforts, both flight test engines will use earth-storable propellants for their RBCC rocket primaries and hydrocarbon fuel for their airbreathing modes. Performance and vehicle sizing results are presented for both options.