| 1. |
- Böhnke, D., et al.
(författare)
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Towards a collaborative and integrated set of open tools for aircraft design
- 2013
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Ingår i: 51st AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition 2013. - Reston, Virigina : American Institute of Aeronautics and Astronautics (AIAA).
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Konferensbidrag (refereegranskat)abstract
- A third generation Multi-Disciplinary Analysis & Optimization setup includes the collaboration of a distributed team of disciplinary experts and their respective anylsis tool to perform aircraft design. The integration of these tools can be eased by the application of open source software leaving more resources for the actual design task. Within the scope of this paper three open tools for aircraft design (OpenVSP, CEASIOM and VAMPzero) are introduced and integrated via a common namespace (CPACS). A design study on a two-engine transport aircraft is set up as an exemplary workflow.
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| 2. |
- Da Ronch, A., et al.
(författare)
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A framework for constrained control allocation using CFD-based tabular data
- 2011
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Ingår i: AIAA Aerosp. Sci. Meet. Incl. New Horiz. Forum Aerosp. Expos.. - Reston, Virigina : American Institute of Aeronautics and Astronautics. - 9781600869501
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Konferensbidrag (refereegranskat)abstract
- This paper describes a framework for control allocation problem using Computational Fluid Dynamics (CFD) aerodata, which is represented by a multidimensional array of dimensionless coefficients of aerodynamic forces and moments, stored as a function of the state vector and control-surface deflections. The challenges addressed are, first, the control surface treatment for the automated generation of aerodata using CFD and, second, sampling and data fusion to allow the timely calculation of large data tables. In this framework, the generation of aerodynamic tables is described based on an efficient sampling/data fusion approach. Also, the treatment of aerodynamics of control surfaces is being addressed for three flow solvers: TORNADO, a vortex-lattice method, and two CFD codes, EDGE from the Swedis Defence Agency and PMB from the University of Liverpool. In TORNADO, the vortex points located at the trailing edge of the flaps are rotated around the hinge line to simulate the deflected surfaces. The transpiration boundary conditions approach is used for modeling moving flaps in EDGE, whereas, the surface deflection is achieved using mode shapes in PMB. The test cases used to illustrate the approaches is the Ranger 2000 fighter trainer and a reduced geometry description of Boeing 747-100. Data tables are then generated for the state vector and multiple control surface deflections. The look-up table aerodata are then used to resolve the control allocation problem under the constraint that each surface has an upper and lower limit of deflection angle.
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| 3. |
- Da Ronch, A., et al.
(författare)
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Benchmarking ceasiom software to predict flight control and flying qualities of the B-747
- 2010
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Ingår i: 27th Congress of the International Council of the Aeronautical Sciences 2010, ICAS 2010. - 9781617820496 ; , s. 2906-2912
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Konferensbidrag (refereegranskat)abstract
- CEASIOM, the Computerized Environment for Aircraft Synthesis and Integrated Optimization Methods, is a framework that integrates discipline-specific tools for conceptual design. At this early stage of the design it is very useful to be able to predict the flying and handling qualities of the aircraft. In order to do this for the configuration being studied, the aerodynamic database needs to be computed and coupled to the stability and control tools to carry out the analysis. This paper describes how the adaptivefidelity CFD module of CEASIOM computes the aerodynamic database of an aircraft configuration, and how that data is analyzed by the FCSDT module to determine the flying qualities and the control laws of the aircraft. The paper compares the predicted flying qualities with the flight-test data of the Boeing B747 aircraft in order to verify the goodness of the overall approach.
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| 4. |
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| 5. |
- Eliasson, P., et al.
(författare)
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Virtual aircraft design of transcruiser - Computing break points in pitch moment curve
- 2010
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Ingår i: 28th AIAA Applied Aerodynamics Conference. - Reston, Virigina : American Institute of Aeronautics and Astronautics (AIAA). ; , s. 2010-4366-
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Konferensbidrag (refereegranskat)abstract
- The SimSAC project has developed the design software CEASIOM, a framework tool that integrates discipline-specific tools like CAD & grid generation, CFD, stability & control analysis etc. for the purpose of aircraft conceptual design. Significant features developed and integrated in CEASIOM are geometry, aerodynamics, flight dynamics and aeroelasticity modules. The design begins with a design specification and uses conventional design methods to prescribe a baseline configuration. Then CEASIOM improves upon this baseline by analyzing its flying and handling qualities. This paper reports on the Transonic cruiser TCR from baseline design to Tier-I design. The baseline T-tail design is based on the design specification, which is a fairly non-complicated one with the exception for the design cruise speed of Mach 0.97. The flight dynamical analysis in CEASIOM of this configuration showed that trimming the aircraft required too large deflections in the design point so a new approach with a canard configuration was designed. A model of this configuration was built and tested in wind tunnel. The paper focuses on the validation of computational tools of different fidelity, from Tier I to Tier II RANS solvers, with test data to get a range of fidelity of the tools. The results showed that Tier I methods fail to reproduce experimental pitch moment already at moderate angles of attack. Euler methods give reasonably accurate predictions but only RANS offers good overall experimental agreement for all angles attack, in particular at higher angles where the flow starts to separate.
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| 6. |
- Mengmeng, Zhang, 1985-, et al.
(författare)
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Enhancement of CEASIOM with Rapid-Meshing Tool for Aircraft Conceptual Design
- 2012
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Ingår i: Aerotecnica Missili & Spazio, The journal of Aerospace Science, Technology and Systems. - : Associazione italiana di Aeronautica e Astronautica. - 2524-6968. ; 91:3/4, s. 79-85
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Tidskriftsartikel (refereegranskat)abstract
- This paper details the development and application of the RDS-SUMO-CEASIOM-EDGE rapid-CFD tool. It uses theRDS CAD model as geometry for automated meshing and CFD analysis to produce an aero-data base for control andstability analysis. It is applied to two non-conventional design proposals, an asymmetric twin-prop aircraft and anairliner with rear Open Rotor propulsion, retractable canard, and a “chin-rudder” instead of vertical tail. For bothconfigurations,yaw control is problematic, and the stability and control analysis is used to assess control surface sizing and stabilityaugmentation system.
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| 7. |
- Mialon, B., et al.
(författare)
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Benchmarking the prediction of dynamic derivatives : Wind tunnel tests, validation, acceleration methods
- 2010
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Ingår i: AIAA Atmospheric Flight Mechanics Conference 2010. - 9781624101519
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Konferensbidrag (refereegranskat)abstract
- The dynamic derivatives are widely used in linear aerodynamic models which are considered to determine the flying qualities of an aircraft: The ability to predict them reliably, quickly and sufficiently early in the design process is more and more important. This paper describes some experimental and computational activities dealing with the determination of dynamic derivatives. The work has been carried out within the FP6 European project SimSAC. Numerical and experimental results are compared for two aircraft configurations: The generic civil transport aircraft, wing-fuselage-tail configuration DLR-F12 and a generic Transonic CRuiser (TCR), which is a canard configuration. Static and dynamic wind tunnel tests have been carried out for both configurations and are briefly described. The data base generated for the TCR configuration includes small amplitude oscillations, dedicated to the determination of dynamic derivatives, and large amplitude oscillations, in order to investigate the dynamic effects on nonlinear aerodynamic characteristics. The influence of the canard has been investigated. Dynamic derivatives have been determined on both configurations with a large panel of tools, from linear aerodynamic (Vortex Lattice Methods) to CFD (unsteady Reynolds-Averaged Navier-Stokes solvers). Strong limitations of linear aerodynamic tools are observed for the canard configuration. A specific attention is paid to acceleration techniques in CFD methods, which allow the computational time to be dramatically reduced while keeping a satisfactory accuracy.
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| 8. |
- Mialon, Bruno, et al.
(författare)
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Validation of numerical prediction of dynamic derivatives : The DLR-F12 and the Transcruiser test cases
- 2011
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Ingår i: Progress in Aerospace Sciences. - : Elsevier BV. - 0376-0421 .- 1873-1724. ; 47:8, s. 674-694
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Forskningsöversikt (refereegranskat)abstract
- The dynamic derivatives are widely used in linear aerodynamic models in order to determine the flying qualities of an aircraft: the ability to predict them reliably, quickly and sufficiently early in the design process is vital in order to avoid late and costly component redesigns. This paper describes experimental and computational research dealing with the determination of dynamic derivatives carried out within the FP6 European project SimSAC. Numerical and experimental results are compared for two aircraft configurations: a generic civil transport aircraft, wing-fuselage-tail configuration called the DLR-F12 and a generic Transonic CRuiser, which is a canard configuration. Static and dynamic wind tunnel tests have been carried out for both configurations and are briefly described within this paper. The data generated for both the DLR-F12 and TCR configurations include force and pressure coefficients obtained during small amplitude pitch, roll and yaw oscillations while the data for the TCR configuration also include large amplitude oscillations, in order to investigate the dynamic effects on nonlinear aerodynamic characteristics. In addition, dynamic derivatives have been determined for both configurations with a large panel of tools, from linear aerodynamic (Vortex Lattice Methods) to CFD. This work confirms that an increase in fidelity level enables the dynamic derivatives to be calculated more accurately. Linear aerodynamics tools are shown to give satisfactory results but are very sensitive to the geometry/mesh input data. Although all the quasi-steady CFD approaches give comparable results (robustness) for steady dynamic derivatives, they do not allow the prediction of unsteady components for the dynamic derivatives (angular derivatives with respect to time): this can be done with either a fully unsteady approach i.e. with a time-marching scheme or with frequency domain solvers, both of which provide comparable results for the DLR-F12 test case. As far as the canard configuration is concerned, strong limitations for the linear aerodynamic tools are observed. A key aspect of this work are the acceleration techniques developed for CFD methods, which allow the computational time to be dramatically reduced while providing comparable results.
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| 9. |
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| 10. |
- Rizzi, Arthur, et al.
(författare)
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Design of a canard configured TransCruiser using CEASIOM
- 2011
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Ingår i: Progress in Aerospace Sciences. - : Elsevier BV. - 0376-0421 .- 1873-1724. ; 47:8, s. 695-705
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Forskningsöversikt (refereegranskat)abstract
- CEASIOM is a multidisciplinary software environment for aircraft design that has been developed as part of the European Framework 6 SimSAC project. It closely integrates discipline-specific tools such as those used for CAD, grid generation, CFD, stability analysis and control system design. The environment allows the user to take an initial design from geometry definition and aerodynamics generation through to full six degrees of freedom simulation and analysis. Key capabilities include variable fidelity aerodynamics tools and aeroelasticity modules. The purpose of this paper is to demonstrate the potential of CEASIOM by presenting the results of a Design, Simulate and Evaluate (DSE) exercise applied to a novel, project specific, transonic cruiser configuration called the TCR. The baseline TCR configuration is first defined using conventional methods, which is then refined and improved within the CEASIOM software environment. A wind tunnel model of this final configuration was then constructed, tested and used to verify the results generated using CEASIOM.
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