Organizational Unit:

Aerospace Systems Design Laboratory (ASDL)

Permanent Link

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

Parent Organization

Organizational Unit

Daniel Guggenheim School of Aerospace Engineering

ArchiveSpace Name Record

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

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Publication Search Results

Now showing 1 - 10 of 112

Design Space Reduction using Multi-Fidelity Model-Based Active Subspaces

(Georgia Institute of Technology, 2023-06) Mufti, Bilal ; Perron, Christian ; Gautier, Raphaël ; Mavris, Dimitri N.

The parameterization of aerodynamic design shapes often results in high-dimensional design spaces, creating challenges when constructing surrogate models for aerodynamic coefficients. Active subspaces offer an effective way to reduce the dimensionality of such spaces, but existing approaches often require a substantial number of gradient evaluations, making them computationally expensive. We propose a multi-fidelity, model-based approach to finding an active subspace that relies solely on direct function evaluations. By using both high- and low-fidelity samples, we develop a model-based approximation of the projection matrix of the active subspace. We evaluate the proposed method by assessing its active subspace recovery characteristics and resulting model prediction accuracy for airfoil and wing drag prediction problems. Our results show that the proposed method successfully recovers the active subspace with an acceptable model prediction error. Furthermore, a cost vs. accuracy comparison with the multi-fidelity gradient-based active subspace method demonstrates that our approach offers comparable predictive performance with lower computational costs. Our findings provide strong evidence supporting the usage of the proposed method to reduce the dimensionality of design spaces when gradient samples are unavailable or expensive to obtain.
Implementing the Digital Thread - A Proof-of-Concept

(Georgia Institute of Technology, 2023-01-25) Oroz, Juan ; Roohi, Zayn ; Abelezele, Sabastian ; Fronk, Gabriel ; Al Fawares, Ruby ; Pinon-Fischer, Olivia ; Gharbi, Aroua ; Marvis, Dimitri ; Petersen, Melissa ; Karl, Alexander ; Matlik, John ; Schwering, Bryan

Current engineering processes are heavily document-centric, which can add time and cost to projects, limit data accessibility, and make it difficult to actively manage models and data consistency throughout the lifecycle of a product. Additionally, traditional data siloes limit data accessibility across departments. Similar issues exist with tools: departments use software with different standards and formats, making it time-consuming and difficult to accurately propagate changes and requirements throughout. Aerospace projects and vehicles are also often a level of magnitude more complex than products developed in other industries, requiring the coupling of multiple disciplines, which intensifies these problems. Digital Engineering and Model-Based Systems Engineering (MBSE) provide the context, methodologies and tools to address some of the aforementioned challenges. In particular, this paper presents the development and implementation of a Digital Thread proof-of-concept for a minimum viable product. In doing so this research demonstrates solutions to the challenges of data acquisition and management, model and data connectivity, tool, and platform integration, eventually leading to the realization of an authoritative source of truth across the product’s lifecycle. Additionally, this research highlights some of the key benefits brought about by the Digital Thread, which include increased collaboration and communication, managed consistency across models and data, as well as the ability to conduct model verification, validation, and calibration - an important tenet of MBSE.
Development of a Parametric Structural Analysis Environment to Support the Design, Manufacturing, and Production of a Composite UAV Wing

(AIAA, 2023-01) dos Santos, Marcos ; Cox, Adam ; Fischer, Olivia J. Pinion ; Mavris, Dimitri N.

As digital and physical systems become more complex, collect voluminous quantities of data, and move towards greater integration over time, the concept of digital engineering has become of great interest in the engineering world. The integration of digital methods with traditional engineering approaches in product lifecycle management has posed challenges on how techniques such as digital twins can be best used during the design and manufacturing phases of the product lifecycle. To address this need, this research supports the integration of design, manufacturing, and production by assessing the structural integrity of various designs of a parametric UAV wing built with a composite material. A systematic and efficient environment is developed to modify the wing design parameters, develop and analyze the finite element model, obtain structural data, and identify feasible design regions for decision making. The sharing of models, data, and analyses with the manufacturing and production segments of the lifecycle permits integration of the various disciplines in early design phases to allow greater design freedom and avoid great costs during the design of the product. The results indicate that (1) the need for a trade-off analysis between key disciplinary considerations in UAV wing design decision making can be addressed and that (2) the developed capability enables decision makers to choose the configurations to be studied in later design stages after the structural integrity and weight considerations are assessed for multiple wing designs.
Multidisciplinary Design Analysis and Optimization of a Hypersonic Inflatable Aerodynamic Decelerator

(Georgia Institute of Technology, 2023-01) Dean, Hayden V. ; Robertson, Bradford E. ; Mavris, Dimitri N.

Human missions to Mars will require advanced entry, descent, and landing (EDL) technology to safely land payloads onto the planet’s surface. With rapidly increasing mass requirements, and stagnant geometry constraints set by current launch vehicles, non-heritage EDL vehicles must be considered to safely land human-scale payloads on Mars. The hypersonic inflatable aerodynamic decelerator (HIAD) is an EDL architecture being evaluated for human-scale payloads to Mars. Parameterization of a HIAD using important geometry variables is generated and used to explore the feasible design space of the entry architecture. The design space is evaluated using GT-Hypersonics, a multidisciplinary design analysis and optimization environment that combines ESP, CBAero, a Dymos-based trajectory optimizer, TPSSizer, and FIAT to perform trajectory, aerodynamic, and aerothermodynamic analysis on a given entry vehicle geometry, and prescribed flight parameters. This analysis is used to size the vehicle’s TPS system, and determine loads experienced by the vehicle during entry. Ranges for geometric inputs were selected and implemented to explore the design space of the HIAD architecture for a use case on Mars using uncrewed and crewed mission constraints. The design spaces for both the uncrewed and crewed missions demonstrated flexibility of inputs, allowing for multiple configurations to be used successfully in a mission to Mars. This study was useful in understanding the future of using the HIAD architecture in space exploration. This study demonstrates the ability to rapidly generate vehicle designs and evaluate their feasibility, a capability that will be useful in the growing space industry.
Defining and Parameterizing the Design Space for Cislunar PNT Architectures

(Georgia Institute of Technology, 2023-01) Bender, Theresa ; Gabhart, Austin ; Steffens, Michael ; Mavris, Dimitri N.

Operations in cislunar space are expected to greatly increase over the next decade, which will place a heightened demand on position, navigation, and timing (PNT) architectures. Existing PNT systems will be unable to support this growth, evidencing the need for a new cislunar PNT infrastructure. This study defines and parameterizes the design space for cislunar PNT architecture development, with the goal of enabling design space exploration and architecture trade studies. Design choices such as orbit type, architecture symmetry, and preferred design variables and their ranges are discussed. An environment for modeling and evaluating PNT architectures is developed and demonstrated on a subset of the defined design space. Preliminary results are shown to exhibit the type of data and trends to be expected from these studies. A discussion of optimization algorithms that can leverage this environment to fully explore the defined design space and identify optimal designs is presented.
Development of an Open Rotor Propulsion System Model and Power Management Strategy

(Georgia Institute of Technology, 2023-01) Clark, Robert A. ; Perron, Christian ; Tai, Jimmy C. M. ; Airdo, Benjamin ; Mavris, Dimitri N.

The development of an open rotor propulsion system architecture model and fuel burn-minimizing power management strategy is investigated. The open rotor architecture consists of a single-rotor open rotor (SROR) connected to the low speed shaft of a traditional turbojet engine in a puller configuration. The proposed architecture is modeled in the Numerical Propulsion System Simulation (NPSS) tool, and performance is evaluated across a complete flight envelope typical for a narrow body commercial airliner. Rotor performance maps are generated using a custom blade element momentum theory (BEMT) code, while compressor performance maps are created using CMPGEN. The performance of the overall propulsion system is detailed in the context of a notional 150 passenger aircraft mission, and a method for scheduling rotor power across the flight envelope is developed in order to minimize aircraft mission fuel burn. It is demonstrated that the power absorbed by the rotor can be optimized by scheduling rotor blade pitch angle versus fan speed. A power management technique using the optimal blade pitch angle at only six points in the flight envelope was shown to provide significant computational benefits without sacrificing any fuel burn when compared to a method using a schedule generated from data across the complete flight envelope.
Uncertainty Quantification of a Parallel Hybrid-Electric Propulsion EPFD Vehicle

(AIAA, 2023-01) Uzodinma, Jaylon ; Zaidi, Turab ; Walter, Miguel ; Gautier, Raphael ; Mavris, Dimitri N.

The NASA Electrified Powertrain Flight Demonstration (EPFD) program is a collaboration between industry and academia to accelerate the development and implementation of megawatt-class power systems in commercial aviation. Technology development programs are often associated with cost, performance, and schedule risks, which can result from technical uncertainty. To assess and offer insight to effective mitigation of risks associated with the NASA EPFD program, an uncertainty quantification analysis for future hybrid-electric commercial aircraft is addressed. An uncertainty analysis is presented for the electrified aircraft propulsion systems of a 150-passenger hybrid-electric aircraft model. Uncertainty at the component-level of the powertrain system is considered and its effect is propagated to vehicle-level metrics. The primary focus is identifying and assessing the key uncertain technological inputs driving the variability of the vehicle’s performance responses.
Decision-Making and Optimization Framework for the Design of Emerging Satellite Constellations

(AIAA, 2023-01) Koerschner, Marc A. ; Krishnan, Kavya Navaneetha ; Payan, Alexia P. ; Mavris, Dimitri N.

With the parallel increase in global orbital debris due to passive object collisions, as well as in the number of proposed low earth orbit mega-constellations, in anti-satellite missile tests, and the fielding of new satellites, there is an inherent need for a framework to optimize the design of Low Earth Orbit (LEO) mega-constellations to avoid collisions while maintaining the functionality of the constellation. In this paper, we aim to provide a framework that unifies these considerations in the conceptual design phase of mega-constellations. We start with a discussion of metrics of importance for the design of mega-constellations, namely coverage, collision risk, collision avoidance, and station-keeping costs. With these metrics defined, we utilize the first principles of orbital mechanics and statistical models to analyze potential alternative mega-constellation designs. These designs are then optimized using Non-denominated Sorting Genetic Algorithm 2 (NSGA2) with our own defined objective function to create a repository of Pareto optimal configurations. We then showcase how a multi-criteria decision-making methodology can be utilized by a variety of unique stakeholders and subject-matter experts to select an optimal constellation design for a given scenario. A Pareto Frontier collection with optimal solutions of 10 constellations was produced by the framework. Radar plots to assess the significance of the weighted metric of the framework shows several trading options for conceptual designs of the constellations. We finally discuss the scope, limitations, applications, and future work for various scenarios.
A Feasibility Study for the Development of Air Mobility Operations within an Airport City (Aerotropolis)

(AIAA, 2023-01) Wang, Xi ; Balchanos, Michael G. ; Mavris, Dimitri N.

This study aims to create a simulation environment to study the feasibility of an Advanced Air Mobility (AAM) system in an airport-centric infrastructure or aerotropolis area. The environment and the study are to confirm the effectiveness of the AAM system in terms of reducing traffic congestion for road networks and the reduction in carbon emissions for transportation methods. The traffic simulation will run a baseline simulation with the currently available mobility methods and an alternative simulation with a proposed small network with close distance flights AAM system of 9 vertiports. The traffic modeling utilizes Agent-Based Modeling (ABM) to accurately models the two cases and compare trip times of the two cases. The emission modeling models the emission of carbon per mile of travel for different mobility methods and use the miles traveled from the traffic simulation to calculate the emission. The conclusion was drawn based on the two comparisons of the change in travel time and the change in emission. A small AAM system servicing a small area with short flight legs is found to be effective in both decreasing trip times and decreasing emissions and is significantly more effective when the ground mobility network is congested and not accessible.
Surrogate Modeling of Orbital Decay of Lunar Orbits

(AIAA, 2023-01) Varoqui, Maxime ; Steffens, Michael J. ; Mavris, Dimitri N.

Operations in cislunar space are expected to greatly increase over the next decade, which will place a heightened demand on satellites operating in cislunar space. The orbit selection of the satellites is a key parameter of the mission. Orbital decay can present significant challenges for some lunar orbits due to gravitational perturbations. This study focuses on developing a fast method to assess the decay of lunar orbits. The method is based on modeling lunar orbits propagation in the presence of these perturbations to quantify orbital decay as a function of orbital parameters, then using the model to generate data and fit surrogate models. Results from this effort will enable decision makers to trade performance and station-keeping costs associated with relevant lunar orbits.