The Experts below are selected from a list of 43467 Experts worldwide ranked by ideXlab platform
Dimitri N. Mavris - One of the best experts on this subject based on the ideXlab platform.
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Average Generic Vehicle Method for Fleet-Level Analysis of Noise and Emission Tradeoffs
Journal of Aircraft, 2018Co-Authors: Matthew J. Levine, Jose Enrique Bernardo, Michelle Kirby, Dimitri N. MavrisAbstract:A method is proposed for modeling average generic vehicles for fleet-Level analysis of technology impacts on environmental metrics. Vehicles are grouped into classes distinguished by Aircraft-Level metrics, which include fuel burn (a surrogate of carbon dioxide emissions), nitrogen oxide species (NOx) emissions, and sound exposure Level noise contours. Target metrics are established for a subset of 94 airports by designing a series of tests of sequentially increasing complexity, with ideal average generic vehicle models minimizing the error distributions across these airports when Aircraft-Level performance is aggregated to fleet Levels. A Latin hypercube design of experiments is employed to explore the Aircraft-Level design space and construct surrogate models for each metric. Monte Carlo samplings of these surrogate models are paired with desirability functions to rapidly identify locations in the design space that simultaneously match aggregate fuel burn, NOx emissions, and day/night-Level contours. In...
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Effect of Major Subsystem Power Off-takes on Aircraft Performance in More Electric Aircraft Architectures
15th AIAA Aviation Technology Integration and Operations Conference, 2015Co-Authors: Imon Chakraborty, Metin F. Ozcan, Dimitri N. MavrisAbstract:The gas turbine engines on commercial Aircraft produce both propulsive power and non-propulsive or secondary power for Aircraft subsystems, which can be in the form of either pneumatic or mechanical power off-take. While there is a degradation in performance and an increase in the thrust-specific fuel consumption in both cases, the extent is not necessarily identical. In addition, subsystem architecture choices also have an effect on Aircraft empty weight and possibly on drag. Therefore, the current industry trend towards More Electric subsystem architectures has potentially far-reaching impacts on Aircraft performance. To ascertain the effect of subsystem architecture choices on Aircraft-Level and mission-Level metrics of interest, the subsystems as well as their impacts on the Aircraft and propulsion system must be modeled in suitable detail. Such an approach is demonstrated in this paper for the case of a representative single-aisle Aircraft with a focus on two subsystems which collectively consume a large fraction of the Aircraft’s total secondary power requirements the Environmental Control System and the Ice Protection Systems.
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A Multi-Stage Surrogate Modeling Approach to Examine Vehicle-Level Technology Impacts at the Airport-Level
53rd AIAA Aerospace Sciences Meeting, 2015Co-Authors: Jose Enrique Bernardo, Clement Besson, Holger Pfaender, Jeff Schutte, Dimitri N. MavrisAbstract:Fleet-Level analysis of technology scenarios are necessary to examine the system impact of potential technology packages applied at the Aircraft Level. Typically, fleet analyses require significant amounts of information to perform detailed model runs. This approach makes it difficult to analyze a broad set of technology scenarios because each one requires time consuming modeling. This paper presents a multi-stage surrogate modeling approach capable of examining vehicle-Level technology impacts to noise at the airport-Level. This process was developed to provide a dynamic dashboard evaluation of vehicle-Level technology rolled up to the system-Level (a representative airport in this case). The approach defines a subset grid of data that are each treated like an individual noise metric at the Aircraft Level. Surrogate models are developed to represent Aircraft-Level noise at these locations as a function of Aircraft technology and design characteristics. The subset grid is small enough that Aircraft-Level noise can be aggregated to the airport Level almost instantaneously. Once at the airport-Level a separate set of surrogate models utilizes the airport-Level noise values to determine the location and size of the Day-Night Average Level (DNL) 65 dB contour. The approach is described in detail, including generation of the surrogate models. Finally several notional scenarios are examined to evaluate the ability of the approach to represent the size and location of the DNL 65 dB contour as a function of Aircraft-Level settings.
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A Surrogate Model based Constrained Optimization Architecture for the Optimal Design of Electrohydrostatic Actuators for Aircraft Flight Control Surfaces
51st AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition, 2013Co-Authors: Chaitanya Hegde, Imon Chakraborty, David Trawick, Hyun Choi, Eugina Mendez-ramos, Dimitri N. MavrisAbstract:This work pertains to the development of an optimization architecture for the optimal design of electrohydrostatic actuators for Aircraft flight control surfaces in the presence of subsystem and Aircraft Level design constraints. A Modeling and Simulation (M&S) environment, described in detail in a separate work, is used to simulate an Aircraft mission and capture relevant and constraining flight conditions and load cases. The system behavior is represented by a surrogate model that allows for rapid and computationally inexpensive evaluation of the responses of interest. The surrogate model is used to perform constrained optimization, followed by a validation of the optimal result using the M&S environment. The optimal designs obtained for two United States Air Force combat Aircraft are presented and discussed, but the methodology is equally valid for other Aircraft and control surface configurations. An additional capability arising from this architecture is the ability to analyze the sensitivity of the design to each of the design parameters influencing it.
Kristof Risse - One of the best experts on this subject based on the ideXlab platform.
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The DLR TuLam project: design of a short and medium range transport Aircraft with forward swept NLF wing
CEAS Aeronautical Journal, 2019Co-Authors: Arne Seitz, A. Hubner, Kristof RisseAbstract:In order to further raise the Technology Readiness Level (TRL) of laminar technologies in Aircraft design the German Aerospace Center DLR conducted an internal project called TuLam (Toughen up Laminar Technology), which lasted from 2014 to 2017. In the course of the project two technology paths were pursued, namely Natural Laminar Flow (NLF) and Hybrid Laminar Flow Control (HLFC). Within the frame of the NLF path a short and medium range transport Aircraft with forward swept laminar wing was designed. The present paper is focused on the aerodynamic design of the forward swept wing in cruise flight. As a special feature in comparison with previous designs of transonic laminar flow wings a trailing edge flap of 10% chord depth is employed to allow for an adaptation of the laminar bucket to off-design conditions. The resulting wing was assessed on overall Aircraft Level with respect to its fuel reduction potential, whereby the CSR-01 configuration, essentially a re-design of the Airbus A320-200, was used as a reference.
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A Functional Approach to a Collaborative Iintegrated Wing and Movables Design
2018 AIAA Aerospace Sciences Meeting, 2018Co-Authors: Giorgio Enrico Bona, Kristof RisseAbstract:This paper presents a design methodology to model the wing, its movables, and the related integrational details. It is based on a functional approach to analyze the design problem, synthesizing it to a compact set of measurable and representative parameters. The methodology has been implemented in a collaborative and cross-organizational way, the result being an automated multidisciplinary process mirrored between industrial and research partners. After presenting the general methodology and its implementation, the focus is set on assessing the multiple impacts of different movables technologies on the design of the wing while capturing their value for both the manufacturer and the operator. These aspects are not evaluated at Aircraft Level only, but they even include safety of System architectures and the integration of components behind the rear spar.
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Central Reference Aircraft data System (CeRAS) for research community
CEAS Aeronautical Journal, 2016Co-Authors: Kristof Risse, Florian Schültke, Katharina Schafer, Eike StumpfAbstract:This paper gives an overview and presents the results of the project CeRAS, which stands for “Central Reference Aircraft data System”. CeRAS is intended to serve as an open platform hosting reference Aircraft data and methods that can be used by a research community in aeronautic research projects. The technical topics of the addressed user group lie in the field of overall Aircraft design as well as technology integration and evaluation on Aircraft Level. To enable the communication within the research community the CeRAS homepage has been created (http://ceras.ilr.rwth-aachen.de/) and filled with a first short-range reference Aircraft dataset. The research community can contribute to and communicate via the CeRAS homepage that is intended to serve as living “open source” platform. The first reference Aircraft is called CSR-01 and has been designed with the ILR Aircraft design platform MICADO. The Aircraft design characteristics are presented and discussed within this paper. Furthermore, common standards for monetary assessment methodologies are presented that have already been established and agreed within the CeRAS research community.
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Conceptual Aircraft design with hybrid laminar flow control
CEAS Aeronautical Journal, 2014Co-Authors: Kristof Risse, Eike StumpfAbstract:This paper describes a methodology for conceptual design and optimization of Aircraft with hybrid laminar flow control (HLFC) systems integrated into wing and tails. An existing conceptual Aircraft design platform is enhanced by the necessary methods for sizing of HLFC system architecture and prediction of aerodynamic drag polars. These include transonic drag characteristics as well as transition prediction by analysing boundary layer instability mechanisms. The implemented methods are described and its sensitivities against relevant Aircraft design parameters are discussed. The integrated sizing methodology allows to assess the net benefit of HLFC system integration on overall Aircraft Level and to minimize Aircraft fuel consumption by variation of Aircraft design parameters, cruise conditions and HLFC system parameters. To demonstrate the applicability of the developed methodology in conceptual Aircraft design it is used for design and assessment of an HLFC long-range passenger Aircraft. The influence of the HLFC main drivers Mach number and wing sweep angle on aerodynamics, systems and Aircraft design characteristics is investigated. Further, Aircraft component resizing is analysed to further exploit the fuel reduction potential of the HLFC technology.
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Assessment of an Innovative Morphing Leading Edge Considering Uncertainties in Conceptual Design
12th AIAA Aviation Technology Integration and Operations (ATIO) Conference and 14th AIAA ISSMO Multidisciplinary Analysis and Optimization Conference, 2012Co-Authors: Tim Lammering, Kristof Risse, Katharina Franz, Eike StumpfAbstract:ow technology is its incompatibility with conventional leading edge high-lift systems. Current research that is funded within the EC 7th Framework Program Collaborative project SADE concentrates on the development of an innovative morphing leading edge system. The project recently concluded in conceptual design, feasibility studies as well as in hardware and wind tunnel testing of the technology. For integration and technology assessment on overall Aircraft-Level, the concept lacks the required maturity in important design parameters such as estimated system mass or high-lift performance. In the scope of this paper, a framework is presented that allows for integrating and assessing innovative technology already in the conceptual design phase on overall Aircraft-Level by considering the most important design uncertainties with a probabilistic approach. Further, the proposed framework concludes in denition of minimum performance margins for the innovative technology, which are directly fed back into the systems development process as direct performance requirements. In a case study, the proposed framework is applied to technology assessment of an innovative morphing leading edge for a commercial transport Aircraft with natural laminar ow technology. The assessment is based on technical parameters such as fuel eciency and specic hourly productivity.
Martin Hepperle - One of the best experts on this subject based on the ideXlab platform.
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Exploring Vehicle Level Benefits of Revolutionary Technology Progress via Aircraft Design and Optimization
Energies, 2018Co-Authors: Yaolong Liu, Ali Elham, Peter Horst, Martin HepperleAbstract:It is always a strong motivation for aeronautic researchers and engineers to reduce the Aircraft emissions or even to achieve emission-free air transport. In this paper, the impacts of different game-changing technologies together on the reduction of Aircraft fuel consumption and emissions are studied. In particular, a general tool has been developed for the technology assessment, integration and also for the overall Aircraft multidisciplinary design optimization. The validity and robustness of the tool has been verified through comparative and sensitivity studies. The overall Aircraft Level technology assessment and optimization showed that promising fuel efficiency improvements are possible. Though, additional strategies are required to reach the aviation emission reduction goals for short and medium range configurations.
Eike Stumpf - One of the best experts on this subject based on the ideXlab platform.
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Estimation of Vehicle-Level Fuel Burn Benefits of Aircraft Formation Flight
Journal of Aircraft, 2018Co-Authors: Yaolong Liu, Eike StumpfAbstract:The present paper investigates the overall Aircraft-Level impact of formation flight in terms of total drag savings and fuel consumption reductions. The current work is carried out on the basis of an in-house multidisciplinary integrated conceptual Aircraft design optimization framework. An aerodynamic method based on potential flow theory is first adapted for the induced drag estimation of Aircraft in formation flight. By integrating the formation flight aerodynamic methodology into the in-house Aircraft design and optimization platform, the potential drag reduction for arbitrary Aircraft configurations in formation can be assessed. For specific flight missions, the fuel burn reduction can be further determined. Through comparing with other simulation and experimental results, the proposed formation flight aerodynamic methods in the present work show very good agreement. A case study on two medium-range passenger Aircraft indicates that the trailing Aircraft could achieve up to 60% induced drag reduction...
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Central Reference Aircraft data System (CeRAS) for research community
CEAS Aeronautical Journal, 2016Co-Authors: Kristof Risse, Florian Schültke, Katharina Schafer, Eike StumpfAbstract:This paper gives an overview and presents the results of the project CeRAS, which stands for “Central Reference Aircraft data System”. CeRAS is intended to serve as an open platform hosting reference Aircraft data and methods that can be used by a research community in aeronautic research projects. The technical topics of the addressed user group lie in the field of overall Aircraft design as well as technology integration and evaluation on Aircraft Level. To enable the communication within the research community the CeRAS homepage has been created (http://ceras.ilr.rwth-aachen.de/) and filled with a first short-range reference Aircraft dataset. The research community can contribute to and communicate via the CeRAS homepage that is intended to serve as living “open source” platform. The first reference Aircraft is called CSR-01 and has been designed with the ILR Aircraft design platform MICADO. The Aircraft design characteristics are presented and discussed within this paper. Furthermore, common standards for monetary assessment methodologies are presented that have already been established and agreed within the CeRAS research community.
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Morphing Value Assessment on Overall Aircraft Level
Smart Intelligent Aircraft Structures (SARISTU), 2015Co-Authors: Fabian Peter, Eike Stumpf, Giovanni Marco Carossa, Markus Kintscher, Ignazio Dimino, Antonio Concilio, Rosario Pecora, Andreas WildschekAbstract:In order to assess the benefit of the morphing devices developed in the framework of SARISTU, integration in an overall Aircraft model is required. For this purpose, the relevant input data regarding the adaptive leading-edge, trailing-edge and winglet devices are gathered with specific focus on weight and aerodynamic performance. Different Levels of detail are applied. For weight and actuation power, the methods range from geometry (e.g. span and chord)-dependent methods to absolute delta values which are for instance subtracted from components weights as wing structure weight. Methods for aerodynamic data reach from subtractions of absolute values from the lift to drag ratio, constant for the flight phases (i.e. climb, cruise, decent), towards changes to the induced drag polars specific for each mission increment and dependent on the explicit lift coefficient. For an objective assessment, several Aircraft models are compared. The assessment and comparison of these Aircraft AC models take place on standard overall Aircraft-Level parameters as block fuel or maximum take-off weight.
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Conceptual Aircraft design with hybrid laminar flow control
CEAS Aeronautical Journal, 2014Co-Authors: Kristof Risse, Eike StumpfAbstract:This paper describes a methodology for conceptual design and optimization of Aircraft with hybrid laminar flow control (HLFC) systems integrated into wing and tails. An existing conceptual Aircraft design platform is enhanced by the necessary methods for sizing of HLFC system architecture and prediction of aerodynamic drag polars. These include transonic drag characteristics as well as transition prediction by analysing boundary layer instability mechanisms. The implemented methods are described and its sensitivities against relevant Aircraft design parameters are discussed. The integrated sizing methodology allows to assess the net benefit of HLFC system integration on overall Aircraft Level and to minimize Aircraft fuel consumption by variation of Aircraft design parameters, cruise conditions and HLFC system parameters. To demonstrate the applicability of the developed methodology in conceptual Aircraft design it is used for design and assessment of an HLFC long-range passenger Aircraft. The influence of the HLFC main drivers Mach number and wing sweep angle on aerodynamics, systems and Aircraft design characteristics is investigated. Further, Aircraft component resizing is analysed to further exploit the fuel reduction potential of the HLFC technology.
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Assessment of an Innovative Morphing Leading Edge Considering Uncertainties in Conceptual Design
12th AIAA Aviation Technology Integration and Operations (ATIO) Conference and 14th AIAA ISSMO Multidisciplinary Analysis and Optimization Conference, 2012Co-Authors: Tim Lammering, Kristof Risse, Katharina Franz, Eike StumpfAbstract:ow technology is its incompatibility with conventional leading edge high-lift systems. Current research that is funded within the EC 7th Framework Program Collaborative project SADE concentrates on the development of an innovative morphing leading edge system. The project recently concluded in conceptual design, feasibility studies as well as in hardware and wind tunnel testing of the technology. For integration and technology assessment on overall Aircraft-Level, the concept lacks the required maturity in important design parameters such as estimated system mass or high-lift performance. In the scope of this paper, a framework is presented that allows for integrating and assessing innovative technology already in the conceptual design phase on overall Aircraft-Level by considering the most important design uncertainties with a probabilistic approach. Further, the proposed framework concludes in denition of minimum performance margins for the innovative technology, which are directly fed back into the systems development process as direct performance requirements. In a case study, the proposed framework is applied to technology assessment of an innovative morphing leading edge for a commercial transport Aircraft with natural laminar ow technology. The assessment is based on technical parameters such as fuel eciency and specic hourly productivity.
David I. Stern - One of the best experts on this subject based on the ideXlab platform.
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Flying More Efficiently: Joint Impacts of Fuel Prices, Capital Costs and Fleet Size on Airline Fleet Fuel Economy
Ecological Economics, 2020Co-Authors: Zsuzsanna Csereklyei, David I. SternAbstract:We investigate the factors that affect airlines' choice of fleet fuel economy using Aircraft-Level data for 1267 airlines in 174 countries. Larger and newer Aircraft are usually more fuel-efficient. Controlling for the effect of Aircraft size and age, we find that the technically achievable fleet fuel economy improves with the size of airlines and the price of fuel and worsens with higher capital costs. The elasticity of fuel economy with respect to the price of fuel is between −0.07 and −0.13. We find evidence for regional differences in fleet fuel economy that are attributable to the adoption of distinct groups of technologies.
