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Daniel Guggenheim School of Aerospace Engineering

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Now showing 1 - 10 of 1409
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    Stagnating turbulent reacting flows
    (Georgia Institute of Technology, 1983) Strahle, Warren Charles ; Daniel Guggenheim School of Aerospace Engineering ; Office of Sponsored Programs ; College of Engineering
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    An Approach for Fan Stage Conceptual Design with Non-Axisymmetric Stators in Presence of Distortion
    (Georgia Institute of Technology, 2020-06) Pokhrel, Manish ; Gladin, Jonathan ; Denney, Russell K. ; Mavris, Dimitri N. ; Daniel Guggenheim School of Aerospace Engineering ; Aerospace Systems Design Laboratory (ASDL) ; College of Engineering
    Advances in the study of distortion warrant the consideration of non-axisymmetric flow field impacts on fan designs. The lack of a method that considers such impacts in early design motivates this work. An approach to design a fan stage in the presence of distortion is developed and illustrated here. In the proposed approach, an extension of the multi-meanline method accounts for flow asymmetry. Blade metal angles for the rotor are designed considering minimization of overall rotor losses in presence of incidence swings. Corrections to the quasi-steady rotor exit conditions provide an approximation to the unsteady rotor response. Non-axisymmetric stators are designed to reduce stage losses. The concept of Multi-Design Point (MDP) approach in the thermodynamic cycle designs inspires this work. This approach is envisioned as a method to approximate the design point of a fan stage under distorted flow conditions.
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    Continuous Descent Arrival
    (Georgia Institute of Technology, 2008) Daniel Guggenheim School of Aerospace Engineering ; Air Transportation Laboratory ; College of Engineering
    Overview of Continuous Descent Arrival research activities in the Air Transportation Laboratory at Georgia Institute of Technology.
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    Adaptive Control of Evolving Gossamer Structures
    (Georgia Institute of Technology, 2006-08) Yang, Bong-Jun ; Calise, Anthony J. ; Craig, James I. ; Whorton, Mark S. ; Daniel Guggenheim School of Aerospace Engineering ; Aerospace Design Group ; College of Engineering
    A solar sail is an example of a gossamer structure that is proposed as an propulsion system for future space missions. Since it is a large scale flexible structure that requires a long time for its deployment, active control may be required to prevent it from deviating into a non-recoverable state. In this paper, we conceptually address control of an evolving flexible structure using a growing double pendulum model. Controlling an evolving system poses a major challenge to control design because it involves time-varying parameters, such as inertia and stiffness. By employing a neural network based adaptive control, we illustrate that the evolving double pendulum can be effectively regulated when fixed-gain controllers are deficient due to presence of time-varying parameters.
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    Validation and Verification Approach for European Safe Precision Landing Guidance, Navigation and Control (GNC) Technologies
    (Georgia Institute of Technology, 2008-06-25) Pradier, Alain ; Philippe, Christian ; Daniel Guggenheim School of Aerospace Engineering ; College of Engineering
    Autonomous safe precision landing is an important capability required to ensure mission success for future robotics exploration landing missions. The landers will be able to automatically identify the location of the desired landing site while detecting hazardous terrain features within it during the final powered descent to the surface, to designate an alternate safe landing site, and to maneuver to the selected safe site. In this respect, the European Space Agency (ESA) has supported for many years the preparation of European solutions for autonomous safe precision landing Guidance, Navigation and Control (GNC) systems. The GNC technologies under development include autonomous vision-based and lidar-based navigation systems (image processing, autonomous navigation algorithms, APS camera and imaging Lidar breadboard), terminal descent algorithms encompassing onboard capabilities for terrain relative navigation, hazard map generation, re-designation of safe target during powered descent. These technologies are presently at different maturity level and are developed to support primarily safe precision landing missions to Mars and Moon. The performance validation and verification approach for safe precision landing systems differs from traditional spacecraft system validation. As the main components of such systems, such as relative-terrain sensors, interact strongly with the planetary surface environments, the performance validation plan has to make use of a complex combination of analysis, simulation, and numerous Earth based flight and facility tests. For instance, the validation of the sensors and terrain analysis algorithms must be tested in the field to prove their performance in a relevant environment. These field tests will establish the accuracy and performance of the relative-terrain navigation systems under a range of descent velocities, attitude dynamics, and terrain. The field test results will also be used for validating high fidelity software models that are used in end-to-end simulations and avionics testbeds. The incremental validation and verification approach consisting of one rapid prototyping of critical algorithms, software and hardware followed by integration into ground and terrestrial technology testbeds where critical interfaces can be validated, performances under representative planetary environment demonstrated, and integration and test procedures developed and verified will be discussed. The suite of simulation tools and ground test facility for the performance validation and verification of autonomous safe precision landing GNC systems will be presented with special emphasis on the high fidelity end-to-end Entry, Descent and Landing Simulator (EAGLE) and the Precision Landing GNC Test Facility (PLGTF). EAGLE, for Entry and Guided Landing Environment, supports the entire life-cycle of an exploration mission, from conceptual design through to flight operations including non-real-time flight software development and testing, and real-time EDL testbeds with hardware-in-the-loop capabilities. A key feature of EAGLE is the ability to model relative-terrain sensors response and synthesize images for onboard vision based control algorithms. This is made possible thanks to PANGU (Planet and Asteroid Natural Scene Generation Utility) a software tool for simulating and visualizing the surface of various planetary bodies: Moon, Mercury, Mars and Asteroids. The PLGTF is based on the Schiebel Camcopter(R) S-100 a highly versatile autonomous Unmanned Aerial Vehicle (UAV). The Camcopter is powered by an aviation-certified rotary engine, with a payload capability of approximately of 50 kg, a maximum speed of 67 m/s and a service ceiling above 4000 m. The PLGTF will support planetary landing related tasks, including "Vision / Lidar based hazard avoidance" and "Landmarks navigation for pinpoint landing" tasks.
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    Development and implementation of a capability-planning framework
    (Georgia Institute of Technology, 2006-12-21) Mavris, Dimitri N. ; Daniel Guggenheim School of Aerospace Engineering ; Office of Sponsored Programs ; College of Engineering
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    Effect of tip radius on the discharge coefficient of a flat plate
    (Georgia Institute of Technology, 1982) McMahon, Howard Martin ; Daniel Guggenheim School of Aerospace Engineering ; Office of Sponsored Programs ; College of Engineering
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    An Extended Savings Algorithm for UAS-based Delivery Systems
    (Georgia Institute of Technology, 2019) Choi, Younghoon ; Choi, Youngjun ; Briceno, Simon I. ; Mavris, Dimitri N. ; Daniel Guggenheim School of Aerospace Engineering ; Aerospace Systems Design Laboratory (ASDL) ; College of Engineering
    This paper presents an extended savings algorithm for a package delivery system using unmanned aircraft systems (UAS). The savings algorithm as a heuristic method solves a vehicle routing problem (VRP) that is commonly formulated by an operational plan for each vehicle. In general, package delivery systems need to establish an operational plan based on demand and preferred time to be visited for each customer. In UAS-based delivery systems, however, capacity and traveling time constraints must be additionally considered to create their operational schedules because of limited payload capacity and short endurance of unmanned aerial vehicles (UAVs). Because of these limitations, UAVs should be reused during operation hours to reduce acquisition costs. Thus, a recharging strategy should be included in the operational planning process. However, conventional savings algorithms cannot capture those properties at once because they have mainly focused on delivery systems with conventional vehicles such as trucks and passenger/cargo aircraft that have different vehicle features and operational characteristics, such as the endurance/speed of a vehicle and recharging strategy. To overcome the limitations of the conventional approaches, this paper proposes the extended savings algorithm, which can concurrently reflect the characteristics of both delivery systems and UAVs. To demonstrate the proposed extended savings algorithm this paper preforms numerical simulations with two representative scenarios in Annapolis, MD and Macon, GA.
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    Collaborative Search and Pursuit for Autonomous Helicopters
    (Georgia Institute of Technology, 2014-05) Johnson, Eric N. ; Mooney, John G. ; Daniel Guggenheim School of Aerospace Engineering ; Unmanned Aerial Vehicle Research Facility
    This paper describes recent results to develop, improve, and flight test a multi-aircraft collaborative architecture, focused on decentralized autonomous decision-making. The architecture includes a search coverage algorithm, behavior estimation, and a pursuit algorithm designed to solve a scenario-driven challenge problem. The architecture was implemented on a pair of Yamaha RMAX helicopters outfitted with modular avionics, as well as an associated set of simulation tools. Simulation and flight test results for single- and multiple- aircraft scenarios are presented. Further work suggested includes identification and development of more sophisticated methods that can replace the simpler elements in modular fashion.
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    Reusable Exploration Vehicle (REV): Orbital Space Tourism Concept
    (Georgia Institute of Technology, 2005-05) Clark, Ian G. ; Francis, Scott R. ; Otero, Richard E. ; Wells, Grant William ; Daniel Guggenheim School of Aerospace Engineering ; Aerospace Systems Design Laboratory (ASDL) ; College of Engineering
    On the heels of the recent success of the X-Prize, sub-orbital space tourism is nearly a reality. Though the requirements are significantly tougher, orbital space tourism is the next logical step. The Reusable Exploration Vehicle (REV) concept is an economically feasible design capable of making this next step. Centered around a lenticular lifting body, the REV concept relies on commercial launch vehicles to reduce DDT&E expenditures. Capable of ferrying five passengers and one crew member for three orbits, the REV is shown to be capable of keeping maximum debt exposure to less than $250M while attaining an IRR of 70% with an estimated market capture of 66%.