59 research outputs found
LAPCAT-II: Conceptual design of a mach 8 TBCC civil aircraft, enforced by full navier-stokes 3D nose-to-tail computation
No full textWithin the frame of the LAPCAT II project (Long-term Advanced Propulsion Concepts and Technologies, funded by the European Commission as part of the 7th Frame Program and involving 16 European research labs and industries), four concurrent system studies have been carried out to design a Mach 8 vehicle able to carry passengers on the Brussels-Sydney route. The required range is above 18000 km, and the defined number of passengers is 300, which correspond to a 60 tons / 1400 m3 payload. Inspired by the previous analysis led by Onera on PREPHA-based concepts 1, by the University of Rome on TBCC hypersonic performances 2, 3 and by Université Libre de Bruxelles on precooled turbofan performances 4, a deeper analysis on a LH2 turbofan/ramjet/scramjet concept was performed, including a parametric sizing of the vehicle, a more detailed internal layout and especially a step-by-step numerical analysis of the aeropropulsive performances on the Mach 8 cruise point, using a nose-to-tail approach. These steps will be described in the paper. © 2011 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved
Robust multidisciplinary analysis and optimization for conceptual design of flexible aircraft under dynamic aeroelastic constraints
No full textWe present a computational framework for robust multidisciplinary design and optimization of flexible aircraft, suited for the conceptual design exploration phase. Constraints are representative of some dynamic aeroelastic effects, including flutter and gust-induced structural stresses. Uncertainties on wing structural parameters are considered, and reliability-based optimization under dynamic aeroelastic constraints is addressed by a Bayesian approach. This work details the implementation aspects, covering disciplinary software tools and the overall aircraft design suite, the optimization algorithm and the approach to propagate uncertainty efficiently. Results are thoroughly discussed for a reference aircraft, which is optimized in the study with respect to a few wing parameters including aspect ratio. The proposed approach is compared to a conventional design methodology assuming a rigid airframe. We show that when applied to slender and flexible wings, the latter can produce dangerous non-conservative results, as its predictions are too optimistic both with respect to efficiency and to aeroelastic safety
IMOTHEP: towards hybrid propulsion for commercial aviation
No full textPresentation at the More Electric Aircraft Conference (MEA2021) carried out on October, 20th, 2021
Reducing the Size of Air-breathing Space Launchers to Enlarge Their Perspectives: How It Works
No full textWhatsOpt: a web application for multidisciplinary design analysis and optimization
No full textInternational audienceThis paper describes ONERA's ongoing effort to develop a collaborative environment to support multidisciplinary design analysis and optimization in the context of overall vehicle design team activities. This environment, namely WhatsOpt, is a web application allowing the ONERA experts to define collaboratively aircraft multidisciplinary analyses in terms of disciplines and data exchanges. From that high-level definition, users can generate the source code skeleton required to plug the implementations of disciplines and get an actual executable model of the concept under study. Then, they are able to run numerical methods such as sensibility analysis and design of experiments in order to finally tune the model, define and run optimizations regarding given design target requirements
Design and full 3D nose-to-tail computation of a turbofan+ scramjet Mach 8 civil aircraft
No full textPreliminary study on launcher design - an illustration of Onera's knowledge and tools
No full textInternational audienceMultidisciplinary Design Optimization (MDO) is a collection of engineering methodologies to optimize systems modeled as a set of coupled disciplinary analyses. Launch vehicles are customarily decomposed into interacting submodels for aerodynamics, trajectory, propulsion, mass and structure. The design of launch vehicle consists in determining its architecture to achieve a given mission and this launcher architecture is usually found through an optimization problem solving. Taking into account the different disciplines requires to model and manage the interactions between them all along the optimization process. Onera, the French Aerospace Center for applied research, has an assigned mission which includes the development of disciplinary knowledge in key fields, such as aerodynamics, structure or propulsion, and the design of new aerospace vehicles. To this end, one of the challenges is to manage the complexity of the involved physical phenomena and their interactions in order to generate innovative concepts beyond existing solutions, with a generic methodological approach to be applied to very different systems such as launchers or aircraft. Taking into account this need for design methodology improvement, Onera has been making an important internal effort to develop tools and methodologies that are helpful to build efficient design processes and optimization capabilities.Different topics related to complex system design have been investigated at Onera to facilitate launch vehicle design:a. Deterministic classical MDO formulations for reusable launch vehicle,b. Deterministic dedicated MDO formulations for expendable launch vehicle design relying on transversal decomposition of the design process,c. MDO formulations under uncertainty in order to ensure the reliability and robustness of the launch vehicles with respect to uncertainty.Many projects have been achieved at Onera involving the development of MDO techniques. This paper is focused on several examples of recent use of MDO techniques at Onera in order to illustrate the progress in terms of MDO methodologies. In the rest of the paper, the three topics will be explored relying on illustrative example of problem solved at Onera on launch vehicle design
A Way not to Follow; the Art not to Know. Inspired by Patricia De Martelaere's Work on Taoism
No full text© 2015 by Tijdschrift voor Filosofie. All rights reserved. Patricia De Martelaere (1957-2009) was a Belgian (and Flemish) author, philosopher, and practitioner of shadowboxing. She wrote an inspiring little book on Taoism that stresses the physical, energetic, and martial aspects of its practice. This paper elaborates upon three central ideas from her work, turns them into a direction that she did not envision, and applies them to a critical-historical interpretation of the Taoist texts that she elaborates upon: an active way of non-knowing, the awareness of a shared ground, and the intellectual fertility resulting from this approach. By occasionally putting aside certain assumptions from contemporary research on early Chinese Taoist philosophers - with respect to books, authors, philosophical consistency, schools, etc. - we can offer alternative accounts to the now dominant forms of interpretation. This approach does not take a position in favor of or against the existence or importance of such entities as "books", "philosophers", or "schools" in pre-imperial China. Nor does it promote an alternative for the dominant narratives. It simply allows for a degree of openness with respect to these narratives, thereby allowing for greater nuance that is at risk of being suffocated in the current context of academic philosophy.status: Publishe
Preliminary study on launch vehicle design: Applications of multidisciplinary design optimization methodologies
No full textInternational audienceThe design of complex systems such as launch vehicles involves different fields of expertise that are interconnected. To perform multidisciplinary studies, concurrent engineering aims at providing a collaborative environment which often relies on data set exchange. In order to efficiently achieve system level analyses (uncertainty propagation, sensitivity analysis, optimization, etc.) it is necessary to go beyond data set exchange which limits the capabilities of performance assessments. Multidisciplinary Design Optimization (MDO) methodologies is a collection of engineering methodologies to optimize systems modeled as a set of coupled disciplinary analyses and is a key enabler to extend concurrent engineering capabilities. This paper is focused on several examples of recent developments of MDO methodologies (e.g. MDO with transversal decomposition of the design process, MDO under uncertainty) with applications to launch vehicle design to illustrate the benefices of taking into account the coupling effects between the different physics all along the design process. These methods enable to manage the complexity of the involved physical phenomena and their interactions in order to generate innovative concepts such as reusable launch vehicles beyond existing solutions
Scramjet Powered Vehicle Tests in the ONERA F4 Hotshot Wind Tunnel. Comparison to Numerical Simulations
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