Fleet-Level Environmental Assessments for Feasibility of Aviation Emission Reduction Goals

13-C-AJFE-PU-013This is an open access paper under the terms of the Creative Commons Attribution 4.0 International (CC BY 4.0) license https://creativecommons.org/licenses/by/4.0/. Please cite this article as: Ogunsina, K.E., Chao, H., Kolencherry, N.J., Jain, S., Moolchandani, K.A., DeLaurentis, D., & Crossley, W.A. (2022). Fleet-Level Environmental Assessments for Feasibility of Aviation Emission Reduction Goals. ArXiv, https://doi.org/10.48550/arXiv.2210.11302The International Air Transport Association (IATA) is one of several organizations that have presented goals for future CO2 emissions from commercial aviation with the intent of alleviating the associated environmental impacts. These goals include attaining carbon-neutral growth in the year 2020 and total aviation CO2 emissions in 2050 equal to 50% of 2005 aviation CO2 emissions. This paper presents the use of a simulation-based approach to predict future CO2 emissions from commercial aviation based upon a set of scenarios developed as part of the Aircraft Technology Modeling and Assessment project within ASCENT, the FAA Center of Excellence for Alternative Jet Fuels and the Environment. Results indicate that, in future scenarios with increasing demand for air travel, it is difficult to reduce CO2 emissions in 2050 to levels equal to or below 2005 levels, although neutral CO2 growth after 2020 may be possible. Presented at the Council of Engineering Systems Universities (CESUN) conference in 201

Modeling and Analysis of Complex Systems Design Processes

This work proposes a framework for modeling an organization as a network of autonomous design agents who collectively work on the design of a complex system. The research objective is to identify a design process policy which best suits the current organization evaluated on the basis of the value that it provides to the organization. Consequently, the research question is, “How does an organization comprised of autonomous design teams select a design process policy which provides the highest value?” The proposed framework models design teams as agents who adapt their behavior using information on design variables available from other teams and the incentives in form of rewards from a system-level designer While extant literature on complex systems design has proposed several models of design processes, there is still a need for models that are versatile enough to represent different types of purposes and scopes of hierarchical levels. Further, models still do not account for the social, cultural, and political aspects of design. Due to the invariably long development times of a complex system, the environment’s dynamics such as changing requirements would require all design teams to update their models and decisions during the process. They have to do this while accounting for the decisions of the other teams. The system-level designer, on the other hand, has to ensure that the design teams’ decisions are in the best interest of the organization, which is to maximize value. The work proposed in this research addresses these issues by taking a bottom-up approach to modeling this complex, dynamic and uncertain design environment, where organizational-level outcomes are modeled as a result of decisions of individual teams who respond to local incentives. The system-level designer and the subsystem design teams, are modeled to interact with other agents with whom they share design variables. The subsystem teams first solve their local design problems, and then exchange the results of these problems with other teams. The proposed modeling is versatile to represent human behaviors such as their adding of margins to design variables during the process of information exchange. In each interaction, the receiving teams make decisions to update their local variable values with the one newly available or to continue to use their own value. They make these decisions on the basis of which decision leads to the highest utility measured by a predefined value function. Thus, each team acts in its selfinterest and maximizes its local value. In case they do not arrive at a common design, the system-level designer attempts to assign rewards which incentivize the teams to update designs such that they are compatible with the other teams. In such cases, the teams would be willing to forgo a portion of their utility obtained from the design outcome if they are compensated for this loss by the system-level designer. Therefore, the task of a system-level designer is to solve a compatibility problem which trades off between different subsystems outcomes and arrives as the final design while maximizing the organization’s value. The framework is developed and then described through a series of increasingly complex design cases using a synthetic optimization problem. Following this, an aircraft design problem serves as a demonstration of application of this framework. The results obtained from both the synthetic and the demonstration problem then inform the discussion of various characteristics of a complex systems design process

Impact of environmental constraints and aircraft technology on airline fleet composition

This thesis models an airline\u27s decisions about fleet evolution in order to maintain economic and regulatory viability. The aim is to analyze the fleet evolution under different scenarios of environmental policy and technology availability in order to suggest an optimal fleet under each case. An understanding of the effect of aircraft technologies, fleet size and age distribution, and operational procedures on airline performance may improve the quality of policies to achieve environmental goals. Additionally, the effect of decisions about fleet evolution on air travel is assessed as the change in market demand and profits of an abstracted, benevolent monopolist airline. Attention to the environmental impact of aviation has grown, and this has prompted several organizations such as ICAO (and, in response, NASA) to establish emissions reduction targets to reduce aviation\u27s global climate impact. The introduction of new technology, change in operational procedures, etc. are some of the proposed means to achieve these targets. Of these, this thesis studies the efficacy of implementation of environmental policies in form of emissions constraints as a means to achieve these goals and assesses their impact on an airline\u27s fleet evolution and technology use (along with resulting effects on air travel demand). All studies in this thesis are conducted using the Fleet-level Environmental Evaluation Tool (FLEET), a NASA sponsored simulation tool developed at Purdue University. This tool models airline operational decisions via a resource allocation problem and uses a system dynamics type approach to mimic airline economics, their decisions regarding retirement and acquisition of aircraft and evolution of market demand in response to the economic conditions. The development of an aircraft acquisition model for FLEET is a significant contribution of the author. Further, the author conducted a study of various environmental policies using FLEET. Studies introduce constraints on maximum CO2 emissions that the airline can cause, taxes on airlines for excess emissions, and the use of biofuels. The results obtained indicate that implementation of very strict policies that place a heavy penalty on airlines for environmental inefficiency would lead to a drastic decline in market demand served as well as airline profits. For example, to achieve a 50% reduction of CO2 emissions by 2050 from the 2005 levels, the airlines would need to leave as much as 45% of predicted market demand unmet, thereby significantly reducing their profits. Taxing airlines for excess emissions would lead them to use large aircraft for short distance operations to reduce CO2 produced per seat mile, decreasing the total number of flights. Since taxation provides an economic motive for airlines to seek low emissions operations procedures, it can be an effective means of achieving emissions reduction goals. Finally the use of biofuels, under some assumption of biofuel availability and cost, helps reduce emissions without compromising market demand or airline profits

Fleet-Level Environmental Assessments for Feasibility of Aviation Emission Reduction Goals

The International Air Transport Association (IATA) is one of several organizations that have presented goals for future CO2 emissions from commercial aviation with the intent of alleviating the associated environmental impacts. These goals include attaining carbon-neutral growth in the year 2020 and total aviation CO2 emissions in 2050 equal to 50% of 2005 aviation CO2 emissions. This paper presents the use of a simulation-based approach to predict future CO2 emissions from commercial aviation based upon a set of scenarios developed as part of the Aircraft Technology Modeling and Assessment project within ASCENT, the FAA Center of Excellence for Alternative Jet Fuels and the Environment. Results indicate that, in future scenarios with increasing demand for air travel, it is difficult to reduce CO2 emissions in 2050 to levels equal to or below 2005 levels, although neutral CO2 growth after 2020 may be possible

Applying a Comparative Performance Assessment Framework to Different Airspace Management Concepts for Urban Air Mobility

With the emerging industry of Urban Air Mobility (UAM), a multitude of ideas and concepts are being explored and elaborated to deliver an integrated and harmonized UAM ecosystem. These ideas and concepts are involved in all aspects of the UAM ecosystem, including vehicle technology, airspace system design, infrastructure, and governing regulations. Along with the significant progress on the different UAM research topics, comparative assess-ment frameworks are also being proposed to objectively compare them. Before UAM deployment, stakeholders need to compare the different approaches and determine which one is the better fit to specific needs. This paper focuses on assessing concepts related to UAM airspace management. It aims to apply a comparative assessment framework to three concepts, namely Slot Based Approach (SBA), Trajectory Based Approach (TBA), both devel-oped by DLR within the HorizonUAM project, and Corridor Based Approach (CBA) developed by NASA under the Air Traffic Management – eXploration (ATM-X) project. This paper describes an initial comparative study while delivering the first key findings. The applied methodology is based on simulation runs conducted in different urban areas, Hamburg and Dallas/Fort Worth, using two simulation platforms namely a DLR Simulation using the Remote Component Environment (RCE) and the NASA-developed simulation platform called TestBed. The col-lected results shed light on the advantages and disadvantages of each airspace management concept and help to identify key distinctions between the concepts. Solutions and concepts are often tailored to a specific city, making it difficult to replicate and scale. Indeed, there is no one-size-fits-all concept. This study demonstrates the general applicability of the proposed performance assessment methodology and can serve as the basis for further comparison studies of future airspace management concepts for UAM