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 103

Hyperion: An SSTO Vision Vehicle Concept Utilizing Rocket-Based Combined Cycle Propulsion

(Georgia Institute of Technology, 1999-11) Olds, John R. ; Bradford, John Edward ; Charania, Ashraf ; Ledsinger, Laura Anne ; McCormick, David Jeremy ; Sorensen, Kirk

This paper reports the findings of a conceptual launch vehicle design study performed by members of the Space Systems Design Laboratory at Georgia Tech. Hyperion is a conceptual design for an advanced reusable launch vehicle in the Vision Vehicle class. It is a horizontal takeoff, horizontal landing SSTO vehicle utilizing LOX/LH2 ejector scramjet rocket-based combined cycle (RBCC) propulsion. Hyperion is designed to deliver 20,000 lb. to LEO from the Kennedy Space Center. Gross weight is estimated to be 800,700 lb. and dry weight is estimated to be 123,250 lb. for this mission. Preliminary analysis suggests that, with sufficient launch traffic, Hyperion recurring launch costs will be under 200 dollars per lb. of payload delivered to LEO. However, nonrecurring costs, including development cost and acquisition of three airframes, is expected to be nearly 10.7B dollars. The internal rate of return is only expected to be 8.24 percent. Details of the concept design including external and internal configuration, mass properties, engine performance, trajectory analysis, aeroheating results, and concept cost assessment are given. Highlights of the distributed, collaborative design approach and a summary of trade study results are also provided.
Stargazer: A TSTO Bantam-X Vehicle Concept Utilizing Rocket-Based Combined Cycle Propulsion

(Georgia Institute of Technology, 1999-11) Olds, John R. ; Ledsinger, Laura Anne ; Bradford, John Edward ; Charania, Ashraf ; McCormick, David Jeremy ; Komar, D. R.

This paper presents a new conceptual launch vehicle design in the Bantam-X payload class. The new design is called Stargazer. Stargazer is a two-stage-to-orbit (TSTO) vehicle with a reusable flyback booster and an expendable LOX/RP upper stage. Its payload is 300 lbs. to low earth orbit. The Hankey wedge- shaped booster is powered by four LOX/LH2 ejector scramjet rocket-based combined-cycle engines. Advanced technologies are also used in the booster structures, thermal protection system, and other subsystems. Details of the concept design are given including external and internal configuration, mass properties, engine performance, trajectory analysis, aeroheating results, and a concept cost assessment. The final design was determined to have a gross mass of 115,450 lb. with a booster length of 99 ft. Recurring price per flight was estimated to be $3.49M. The overall conceptual design process and the individual tools and processes used for each discipline are outlined. A summary of trade study results is also given.
Integrating Aeroheating and TPS into Conceptual RLV Design

(Georgia Institute of Technology, 1999-11) Cowart, Karl K. ; Olds, John R.

The purpose of this study is to develop the Thermal Calculation Analysis Tool (TCAT) that will enable Aeroheating and Thermal Protection System (TPS) sizing to be, an on-line, automated process. This process is described as dynamic on-line TPS sizing. It enables the assumptions made about the vehicle TPS to be updated through out the iteration-process. This method is faster and more accurate than a static offline process where the assumptions of the vehicle TPS are held constant during the vehicle design procedure. TCAT will work in conjunction with other engineering disciplines in a Design Structure Matrix (DSM). The unsteady, one dimensional heat diffusion equation was discretized, and resulted in a tridiagonal system of non-linear algebraic equations. This system was implicitly solved using the iterative Newton-Raphson technique at each time level. This technique was conducted for both steady-state and transient conditions that predicted the temperature profiles, and in-depth conduction histories for several TPS material test cases. Also, this was performed on several disparate TPS materials layered together at one time. Finally; comparative benchmark solutions of the TCAT transient analyses were conducted using the commercial software code SINDA/G. Results show that TCAT performed as predicted, and will satisfy the requirement of lowering the amount of time required to conduct TPS sizing for a reusable launch vehicle. Future work will consist of adding temperature dependent material properties to TCAT, coupling TCAT to an optimizer, and creating a web-interface that will enable cross-platform operation of TCAT.
Viable Designs Through a Joint Probabilistic Estimation Technique

(Georgia Institute of Technology, 1999-10) Bandte, Oliver ; Mavris, Dimitri N. ; DeLaurentis, Daniel A.

A key issue in complex systems design is measuring the 'goodness' of a design, i.e. finding a criterion through which a particular design is determined to be the 'best.' Traditional choices in aerospace systems design, such as performance, cost, revenue, reliability, and safety, individually fail to fully capture the life cycle characteristics of the system. Furthermore, current multi-criteria optimization approaches, addressing this problem, rely on deterministic, thus, complete and known information about the system and the environment it is exposed to. In many cases, this information is not be available at the conceptual or preliminary design phases. Hence, critical decisions made in these phases have to draw from only incomplete or uncertain knowledge. One modeling option is to treat this incomplete information probabilistically, accounting for the fact that certain values may be prominent, while the actual value during operation is unknown. Hence, to account for a multi-criteria as well as a probabilistic approach to systems design, a joint-probabilistic formulation is needed to accurately estimate the probability of satisfying the criteria concurrently. When criteria represent objective/ aspiration functions with corresponding goals, this ?int probability?can also be called viability. The proposed approach to probabilistic, multi-criteria aircraft design, called the Joint Probabilistic Decision Making (JPDM) technique, will facilitate precisely this estimate.
An Improved Process for the Generation of Drag Polars for Use in Conceptual/Preliminary Design

(Georgia Institute of Technology, 1999-10) Mavris, Dimitri N. ; Qiu, Songtao

One of the most essential contributors in the aircraft sizing and synthesis process is the creation and utilization of accurate drag polars. An improved general procedure to generate drag polars for conceptual and preliminary design purposes in the form of Response Surface Equations is outlined and discussed in this paper. This approach facilitates and supports aerospace system design studies as well as Multi-disciplinary Analysis and Optimization. The analytically created Response Surface Equations replace the empirical aerodynamic relations or historical data found in sizing and synthesis codes, such as the Flight Optimization System (FLOPS). These equations are commonly incorporated into system level studies when a configuration falls beyond the conventional realm. The approach described here is a statistics-based methodology, which combines the use of Design of Experiments and Response Surface Method (RSM). Computational aerodynamic codes based on linearized potential flow and boundary layer theory are employed to generate the needed parametric relationships. The process is facilitated through the use of an automated computational architecture that is capable of handling massive exchanges of data and information. The aforementioned process is demonstrated through an implementation of the procedure for a High Speed Civil Transport concept. The accuracy of these Response Surface Equations is finally tested to demonstrate the fidelity and accuracy of their predictive capability.
The Implementation of a Conceptual Aerospace Systems Design and Analysis Toolkit

(Georgia Institute of Technology, 1999-10) Hale, Mark A. ; Mavris, Dimitri N. ; Carter, Dennis L.

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.
Elements of an Emerging Virtual Stochastic life Cycle Design Environment

(Georgia Institute of Technology, 1999-10) Mavris, Dimitri N. ; DeLaurentis, Daniel A. ; Hale, Mark A. ; Tai, Jimmy C. M.

The challenge of designing next-generation systems that meet goals for system effectiveness, environmental compatibility, and cost has grown to the point that traditional design methodologies are becoming ineffective. Increases in the analysis complexity required, the number of objectives and constraints to be evaluated, and the multitude of uncertainties in today? design problems are primary drivers of this situation. A new environment for design has been formulated to treat this situation. It is viewed as a testbed, in which new techniques in such areas as design-oriented/physics-based analysis, uncertainty modeling, technology forecasting, system synthesis, and decision-making can be posed as hypotheses. Several recent advances in elements of this multidisciplinary environment, termed the Virtual Stochastic Life Cycle Design Environment, are summarized in this paper.
Enabling Advanced Design Methods in an Internet-Capable Framework

(Georgia Institute of Technology, 1999-10) Hale, Mark A. ; Mavris, Dimitri N.

The enabling of advanced design methods in an internet-capable framework will be discussed in this paper. The resulting framework represents the next generation of design and analysis capability in which engineering decision-making can be done by geographically distributed team members. A new internet technology called the lean-server approach is introduced as a mechanism for granting Web browser access to frameworks and domain analyses. This approach has the underpinnings required to support these next generation frameworks collaboratories. A historical perspective of design frameworks is discussed to provide an understanding of the design functionality that is expected from framework implementations to insure design technology advancement. Two research areas were identified as being important to the development of collaboratories: design portals and collaborative methods. An internet-enabled design framework called IMAGE is highlighted and demonstrated using a probabilistic design example. The prototyped methods have found their way into a Conceptual Aerospace Systems Design and Analysis Toolkit used by the Air Force Research Laboratory.
An Application of a Technology Impact Forecasting (TIF) Method to an Uninhabited Combat Aerial Vehicle

(Georgia Institute of Technology, 1999-10) Mavris, Dimitri N. ; Soban, Danielle Suzanne ; Largent, Matthew Clinton

In today's atmosphere of lower U.S. defense spending and reduced research budgets, determining how to allocate resources for research and design has become a critical and challenging task. In the area of aircraft design there are many promising technologies to be explored, yet limited funds with which to explore them. In addition, issues concerning uncertainty in technology readiness as well as the quantification of the impact of a technology (or combinations of technologies), are of key importance during the design process. The methodology presented in this paper details a comprehensive and structured process in which to explore the effects of technology for a given baseline aircraft. This process, called Technology Impact Forecasting (TIF), involves the creation of a forecasting environment for use in conjunction with defined technology scenarios. The advantages and limitations of the method will be discussed, as well its place in an overall methodology used for technology infusion. In addition, the example TIF application used in this paper, that of an Uninhabited Combat Aerial Vehicle, serves to illustrate the applicability of this methodology to a military system.
Forecasting Technology Uncertainty in Preliminary Aircraft Design

(Georgia Institute of Technology, 1999-10) Kirby, Michelle Rene ; Mavris, Dimitri N.

An evolved version of the Technology Identification, Evaluation, and Selection (TIES) method is presented that provides techniques for quantifying technological uncertainty associated with immature technologies. Uncertainty in this context implies forecasting. Forecasting the impact of immature technologies on a system is needed to provide increased knowledge to a decision-maker in the conceptual and preliminary phases of aircraft design. The increased knowledge allows for proper allocation of company resources and program management. The TIES method addresses the milestones encountered during a technology development program, the sources of uncertainty during that development, a potential method for bounding and forecasting the uncertainty, and a means to quantify the impact of any emerging technology. A proof of concept application was performed on a High Speed Civil Transport concept due to its technically challenging customer requirements.