Person:

Mavris, Dimitri N.

Permanent Link

https://hdl.handle.net/1853/71501

Associated Organization(s)

Organizational Unit

Daniel Guggenheim School of Aerospace Engineering

The Daniel Guggenheim School of Aeronautics was established in 1931, with a name change in 1962 to the School of Aerospace Engineering

Organizational Unit

Aerospace Systems Design Laboratory (ASDL)

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Publication Search Results

Now showing 1 - 10 of 25

Sustainability and Resiliency in Airport Energy Infrastructure: A Multidisciplinary Methodology for Optimizing Building Operations

(Georgia Institute of Technology, 2025-01) Kimanya, Humfrey ; Murugesan, Devesh ; Duncan, Scott ; Mavris, Dimitri N.

There is a striking di!erence in the domain of environmental consciousness: a large amount of greenhouse gases is produced by commercial buildings compared to what is commonly perceived in the transportation sector. The International Panel on Climate Change has labeled buildings as the third largest contributor of greenhouse emissions with at least 17.5%, whereas the aviation industry merely contributes 2%. Hence, there is an urgent need to decarbonize buildings to enhance sustainability, a sound path towards mitigating e!ects of climate change. Moreover, continued power supply to critical buildings such as hospitals and airports, is important to ensure life safety of their users. Power outages in such buildings disrupt operations resulting to substantial financial losses. For instance, the 2017 outage at the Hartsfield Jackson Atlanta Airport in the United States demonstrated the result — a 11-hour period without power which brought Delta airlines about $50M estimated in loss. From a system-of-systems perspective, this paper investigates decarbonizing of buildings and infrastructure by considering aspects of sustainability, resiliency, and a!ordability. A detailed account of scenarios involving power outages, building HVAC systems and the demand of electric vehicles is balanced against the amount of power from the main grid and distributed energy resources including photovoltaics,storage systems and power generators. The aim of this study is to provide a financially optimum combination of grid energy and DERs (Distributed Energy Resources). As such, this study utilizes a proposed methodology that employs use of multi-variate regression models to integrate a building HVAC system modeled using Simcenter Amesim in a representative thermal envelope with an optimization tool developed by the US National Renewable Energy Laboratory. These modeling tools are used to create a parametric and interactive tool that assists stakeholders in assessing tradeo!s for building energy sourcing to meet power demands even during power outages and assess its impacts financially and environmentally.
A Modeling and Simulation Approach to Assessing the Impacts of Accessibility Solutions in the Air Travel System of Systems

(Georgia Institute of Technology, 2025-01) Ergan, Tuna ; Al Atik, Lin ; Lavanchy, Santiago Garcia ; Lewis, Kayley J. ; Kallou, Evanthia ; Garcia, Elena ; Mavris, Dimitri N.

Air travel can be a complicated experience for travelers in a busy and hectic environment, and these difficulties are heightened significantly for disabled passengers. The ability to quickly and safely get from one destination to another is complicated by conditions that cause these passengers to require accessibility accommodations or outside assistance. Although solutions that would make air travel accessible and inclusive for all are needed, the shortcomings of airports, budgets of stakeholders, or even the demographics of travelers vary greatly. This study aims to design and develop a decision-making framework, supported by a stochastic simulation of air travel system of systems, to understand the interactions between various stakeholders and model potential accessibility solutions. Through the direct visualization and exploration of the decision outcomes, airlines, airports, and aircraft manufacturers will be equipped to make informed choices regarding which solutions to prioritize implementing and to what extent for the benefit of both disabled and able-bodied passengers. The ability to use this discrete event simulation model of air travel systems, calibrated to Atlanta Hartsfield-Jackson International Airport and several other airports of various sizes, for decision-making is demonstrated with various case studies throughout this paper.
Uncertain Reduced Order Model Predictions of an Unsteady Field

(Georgia Institute of Technology, 2025-01) Willier, Brenton ; Perron, Christian ; Robertson, Bradford E. ; Mavris, Dimitri N.

The design of blunt-body entry vehicles balances atmospheric heating and drag to ensure payload safety during entry, descent, and landing. Their blunt shape creates turbulent, recirculating wakes, leading to uncertain flight paths and challenging mitigation strategies. Traditionally, uncertainties are managed using conservative scalars and multipliers, resulting in over-engineered designs with reduced payload capacity and less accurate landings. While advances in computational fluid dynamics (CFD) enable high-fidelity analysis, the cost of extensive simulations remains prohibitive. Surrogate models, such as reduced-order models (ROMs), offer a faster alternative but must address the uncertainty introduced by unsteady aerodynamic training data. This paper presents a methodology to capture, encode, and propagate uncertainty in unsteady high-dimensional fields using parametric ROMs. The approach employs a Lorenz model to emulate unsteady fields and applies replication sampling to capture full-order model (FOM) nonparametric uncertainty. Proper orthogonal decomposition (POD) reduces dimensionality, and sparse Kriging regression predicts latent space mean and variance. A linear covariance back-mapping technique is applied to propagate uncertainty from the latent coordinates to integrated scalar coefficients. Results demonstrate the ROM accurately predicts scalar uncertainties consistent with FOM validation, supporting future application to more complex problems, such as entry vehicles in unsteady free-flight simulations.
A Comparative Analysis of Lunar PNT+C Concepts

(Georgia Institute of Technology, 2025-01) Gabhart, Austin ; Drosendahl, Madilyn ; Robertson, Bradford E. ; Mavris, Dimitri N.

With the expected increase in cislunar operations, there are many proposed architectures to provide these missions with Positioning, Navigation, Timing, and Communication (PNT+C) support. While most of the architectures are frequently similar in concept, there is significant variation in how they are evaluated. This paper provides an overview of system architecture alternatives presented in literature to develop requirements for an evaluation environment. To provide insight into the relative performance between architectures, an evaluation environment is described in detail to establish the basis for comparison. The evaluation environment includes orbit determination and time synchronization modeling, an implementation of more accurate dilution of precision metrics, and orbit maintenance maneuver modeling and optimization. The configurations for comparison are selected from literature. It is found that constellations made of highly stable elliptical orbits still require significant ΔV to maintain their orbits. It is also found that increasing the variety of orbits and number of satellites significantly improves the performance of the lunar PNT architecture.
Performance Assessment and Mission-Based Optimization for Next-Generation Single-Aisle Aircraft Conceptual Design

(Georgia Institute of Technology, 2025-01) Patel, Dev P. ; Ergan, Tuna ; Cai, Yu ; Gladin, Jonathan C. ; Mavris, Dimitri N.

This paper presents a comprehensive conceptual design study for the next generation of single-aisle passenger transport, focusing on reducing fuel burn and noise through optimization around mission-based parameters. While much of the industry’s efforts have centered on advanced configurations unlikely to be developed and certified soon, this study emphasizes the importance of optimizing conventional aircraft designs to bridge the gap until their arrival. Technologies expected to mature by 2035 are identified and infused into a large single-aisle aircraft to establish a baseline, primarily because the largest market share among other classes of vehicles, followed by optimization driven by mission-based parameters. 2035 technologies alone resulted in a 19.8% reduction in block fuel for the default design range. Reducing the cruise Mach number and incorporating natural laminar flow further decreased the fuel burn by 8.2%. The reduced range optimization yielded an additional fuel saving of up to 4.1%, though the returns diminish with decreasing range. Overall, the total fuel burn reduction compared to the 2018 Technology Reference Aircraft is estimated to range from 29.2% to 30.8%. This work highlights the potential for significant efficiency improvements in next-generation civil aviation while leveraging mature technologies until the arrival of novel configurations.
Fleet-Level and Global Emissions Impact Analysis of Mission-Optimized Next-Generation Single-Aisle Aircraft

(Georgia Institute of Technology, 2025-01) Ergan, Tuna ; Parashar, Akshiti ; Xie, Jiacheng ; Kirby, Michelle R. ; Mavris, Dimitri N.

With mounting concerns over environmental sustainability, the aviation industry faces pressure to reduce its carbon footprint, not only by redesigning aircraft with advanced technologies and materials but also by exploring new avenues like operations-based optimization. This paper supports these efforts by presenting a comprehensive fleet-level analysis for shortrange single-aisle aircraft entering service around 2035, assessing potential global carbon emission reductions through reduced and optimized cruise speed and design range. Using multiple operational scenarios based on vehicles optimized for different and shorter ranges, the impact of introducing new short-range vehicles into future fleets on fuel burn is compared to the present. Although an aircraft’s fuel consumption decreases with a reduced design range due to a smaller vehicle size and thrust requirement, the reduced design range also limits the number of operations the aircraft can cover. The variants that have the largest impact on global and in-class fuel burn were shown to be the ones sized for a design range closest to covering most or all of the existing missions but without going over. The fleet analysis results provide insights for determining the optimal mission profile for the conceptual design of the next-generation single-aisle aircraft.
Investigation of Weather Considerations for Battery Electric Regional Air Mobility Flights

(Georgia Institute of Technology, 2024-07) Kim, Seulki ; Justin, Cedric Y. ; Mavris, Dmitri N.

Recent advancements in battery electric aircraft technology have elevated their potential as a sustainable and efficient transportation solution for regional air mobility, particularly in enhancing connectivity for under-served communities. However, the lower energy density of onboard batteries presents a notable operational challenge, limiting the usable ranges for flights. This limitation could potentially impede the consistent and reliable deployment of these aircraft in regional flight networks, especially under unfavorable weather conditions. In response, this research proposes a comprehensive methodology to assess the operational impacts on electric aircraft under diverse meteorological scenarios in regional flight network. The proposed framework evaluates critical operational factors for Part 121 (scheduled air carriers) and Part 135 (commuter and on-demand operations), including flight cancellations, flight rules, wind-induced extended distances, and required alternate airport distances. To demonstrate the efficacy of this weather impact methodology, network-level analyses are conducted in two distinct regions of the United States: the Northeast Corridor and Colorado. The results offer information on the operational capabilities and limitations of electric aircraft under different regulatory frameworks. It is expected that these findings will support decision-making processes for regional fight operators and policymakers, facilitating the informed integration of electric aircraft into U.S. regional air mobility networks.
Towards a Framework for Modeling and Simulating Complex Enterprises: The Case of an Academic Research Laboratory

(Georgia Institute of Technology, 2024-01) Lepez Da Silva Duarte, Noe ; Fischer, Olivia J. Pinion ; Mavris, Dimitri N.

This paper presents an initial exploration into a comprehensive, reusable, and scalable approach to enterprise architecture modeling and simulation, with a significant emphasis on the use of SysML. Through a case study of a large academic research laboratory, the research delineates the application of UAF and SysML models with diverse simulation methodologies, prioritizing the seamless transfer and enhanced visualization of SysML model data. A key contribution of this study is the incorporation of ontologies and graph databases through Neo4j, offering a robust framework for representing and querying complex SysML data. By juxtaposing traditional tools, such as SimPy, with Neo4j, the research underscores the effectiveness of graph databases in presenting a clearer, more intuitive visualization. While the presented simulation serves primarily as a proof-of-concept, it sheds light on the complexities of enterprise dynamics. The potential for richer, more detailed simulations that harness the full capability of these tools beckons further exploration in subsequent research endeavors.
A Reduced Order Modeling Approach to Blunt-Body Aerodynamic Modeling

(Georgia Institute of Technology, 2024-01) Dean, Hayden V. ; Decker, Kenneth ; Robertson, Bradford E. ; Mavris, Dimitri N.

Blunt-body entry vehicles display complex flow phenomena that results in dynamic instabilities in the low supersonic to transonic flight regime. Dynamic stability coefficients are typically calculated through parameter identification and trajectory regression techniques using both physical test data and Computational Fluid Dynamics (CFD) simulations. This methodology can generate dynamic stability coefficients, but the resulting data points are limited, and have high degrees of uncertainty due to the nature of data reduction methods. With increased computational capabilities, new methods for dynamic stability quantification have been explored that seek to leverage the high-dimensional aerodynamic data produced from CFD simulations to compute dynamic stability behavior and address the limitations of linearized aerodynamics. The objective of this work is to advance the quantification of dynamic stability behavior of blunt-body entry vehicles by leveraging high-fidelity CFD data through Reduced Order Modeling (ROM). ROMs are capable of leveraging high-fidelity aerodynamic data in a cost effective manner by finding a low-dimensional representation of the Full Order Model (FOM). ROMs based on Proper Orthogonal Decomposition (POD) have shown success in recreating CFD analyses of parametric ROM applications and time-varying ROM applications. Results of this research demonstrated success in constructing two ROMs of a notional blunt-body entry vehicle to recreate heatshield and backshell pressure distributions from forced oscillation trajectories. The ROM was more successful at reconstructing the heatshield pressure distribution, with challenges arising in predicting the chaotic response of backshell latent coordinates.
Optimal Deployment Strategies for Cislunar PNT+C Architectures

(Georgia Institute of Technology, 2024-01) Gabhart, Austin ; Drosendahl, Madilyn ; Robertson, Bradford E. ; Steffens, Michael J. ; Mavris, Dimitri N.

Cislunar operations are expected to rise dramatically within the next decade, requiring a comparable increase in PNT and communications services. However, current PNT systems are at capacity and need to be augmented to serve a cislunar space domain, specifically in the form of novel cislunar PNT architectures. This paper studies the problem of the deployment of PNT and communications satellites, specifically, the problem of deployment strategies spanning multiple stages over extended periods of time. A set of stage definitions will be determined along with areas of potential user activity. A novel application of the hidden gene genetic algorithm to the constellation optimization problem is presented. A design space exploration is presented with comparisons of circular and elliptical constellations. Optimization results from the first stage are also provided. It is shown that acceptable performance can be achieved with a low number of deployed satellites and that strong trade-offs exist between performance and stability.