Sant'Ambrogio di Torino, Italy
Sant'Ambrogio di Torino, Italy

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Mimeau C.,University Grenoble Alpes | Gallizio F.,Optimad Engineering Srl | Cottet G.-H.,University Grenoble Alpes | Mortazavi I.,French National Conservatory of Arts and Crafts
International Journal for Numerical Methods in Fluids | Year: 2015

In this work, a penalization method is discussed in the context of vortex methods for incompressible flows around complex geometries. In particular, we illustrate the method in two cases: the flow around a rotating blade for Reynolds numbers 1000 and 10,000 and the flow past a semi-circular body consisting of a porous layer surrounding a rigid body at Reynolds numbers 550 and 3000. In the latter example, the results are interpreted in terms of control strategy. © 2015 John Wiley & Sons, Ltd.


Grant
Agency: Cordis | Branch: FP7 | Program: CP-FP | Phase: AAT-2007-4.2-01;AAT-2007-4.1-01 | Award Amount: 5.52M | Year: 2009

ALEFs objective is to enable the European aeronautical industry to create complete aerodynamic models of their aircraft based on numerical simulation approaches within the respective development processes. I.e. ALEF will kick-off a paradigm shift from greater confidence in experimentally measured loads data to greater confidence in computational results. Beyond the scope of ALEF this paradigm shift will essentially influence the overall aerodynamic development process. The objective has three aspects: 1. Comprehensiveness refers to the ability to predict aerodynamic forces, moments and their derivatives in time for any point of the flight regime. It is addressed by two complementary approaches: A high fidelity CFD based approach serves short-term impact. Long-term improvements are delivered by incorporation of simulation tools of different fidelity. 2. Quality refers to the accuracy and physical correctness of each flow simulation result used for aero data prediction as well as to a high coherence of aero data integrated over the complete flight envelope from tools of varying fidelity. It is improved by considering the impact of physical modelling as well as novel quality control means to achieve a highly coherent data space representation. 3. Efficiency refers to the necessity to compute the entire aero data space within time frames dictated by industrial design processes at given costs. It is tackled by means of surrogate models for both steady and unsteady flows. Also planning techniques for efficient simulation campaigns are addressed. The ultimate scope of using simulation tools in aero data generation is to cover all flight conditions and configurations by means of a numerical toolbox. This would ensure an up-to-date and fast estimation of most recent statuses of aircraft with every data consistent. ALEF will essentially contribute to a 70% wind tunnel testing cost reduction by 2020, which will cut the aerodynamic development effort by about 40%.


Grant
Agency: Cordis | Branch: H2020 | Program: RIA | Phase: MG-1.1-2014 | Award Amount: 4.29M | Year: 2015

Encounters with atmospheric turbulence are a vitally important in the design and certification of many manmade structures such as aircraft and wind turbines. Gusts cause rapid changes in the flow about the structures which leads to rigid and flexible unsteady responses. Knowledge of aircraft/gust interactions is therefore vital for loads estimation during aircraft design as it impacts on control systems and often defines the maximum loads that these structures will experience in service. At present industry typically uses the linear doublet lattice method with static loads corrections from expensive wind tunnel data. The wind tunnel data is created using the final aerodynamic surface in the predicted cruise shape. This means that gust loads come relatively late when the design options have been narrowed. Increased competition and environmental concerns are likely to lead to the adoption of more flexible materials and the consideration of novel configurations, in which case the linear assumptions of the current gust loads process will become unacceptable. To introduce non-linearity into the gust loads process without significantly increasing the cost and time, this project has three main objectives: to carry out investigations using CFD so that the non-linearities in gust interactions are understood; to create a gust loads process that does not require wind tunnel data and hence reduces the need for wind tunnel testing; to develop updated reduced order models for gust prediction that account for non-linearity at an acceptable cost. These investigations will reduce the need for expensive wind tunnel testing and hence lead to time and cost savings at the design stage therefore ensuring that the European aerospace and defence industry remain competitive in the future. The wind turbine industry has similar concerns, with gusts and wind shear restricting the locations available for wind farms. The project will also address these issues using common methodology.


Grant
Agency: Cordis | Branch: FP7 | Program: CP-FP | Phase: AAT.2008.4.1.1. | Award Amount: 3.66M | Year: 2010

The upstream FFAST project addresses the topic Design Systems and Tools (AAT.2008.4.1.1) by developing, implementing and assessing a range of numerical simulation technologies to accelerate future aircraft design. Critical load identification methods and reduced order modelling techniques developed will potentially provide a step change in the efficiency and accuracy of the dynamic aeroelastic loads process . Identifying the flight conditions that lead to the maximum loads on aircraft structures and introducing higher fidelity methods at these conditions will reduce the cost and turn around time of the loads process of conventional aircraft. This will lead to significant improvements to product development and manufacture, supporting the ACARE 2020 targets. In addition, innovative designs required for green aircraft can be evaluated more rapidly and at lower risk. Reduced order modelling techniques offer the potential for further step changes in the efficiency of the aeroelastic loads process. These offer the accuracy of high fidelity methods at a cost close to that of the current low fidelity methods. The target for the FFAST project is to demonstrate a speed up of 2 to 3 orders of magnitude over high fidelity methods. To meet this target research will be carried out in work packages to: improve identification of critical loads; develop reduced order modelling strategies for unsteady aerodynamic and aeroelastic simulation. A work package dedicated to validation and evaluation on a set of industrially relevant test cases will judge the success of the technologies developed and give industry confidence to make the necessary pull-through investment. Strong industrial support of FFAST allows direct exploitation of the results via focused future investment, the solution data base and early release software. The dissemination of FFAST to a wider audience is vital and will be achieved via a website, targeted lectures and workshops, conferences and journal publications.


Gorsse Y.,University of Bordeaux 1 | Gorsse Y.,French National Center for Scientific Research | Gorsse Y.,French Institute for Research in Computer Science and Automation | Iollo A.,University of Bordeaux 1 | And 5 more authors.
Journal of Computational Physics | Year: 2014

We present a simple numerical method to simulate the interaction of two non-miscible compressible materials separated by an interface. The media considered may have significantly different physical properties and constitutive laws, describing for example fluids or hyperelastic solids. The model is fully Eulerian and the scheme is the same for all materials. We show stiff numerical illustrations in case of gas-gas, gas-water, gas-elastic solid interactions in the large deformation regime. © 2014 Elsevier Inc.


Morency F.,École de Technologie Supérieure of Montreal | Beaugendre H.,University of Bordeaux 1 | Beaugendre H.,French National Center for Scientific Research | Beaugendre H.,French Institute for Research in Computer Science and Automation | And 2 more authors.
International Journal of Computational Fluid Dynamics | Year: 2012

In this work, we propose a formulation to evaluate aerodynamic forces for flow solutions based on Cartesian grids, penalisation and level set functions. The formulation enables the evaluation of forces on closed bodies moving at different velocities. The use of Cartesian grids bypasses the meshing issues, and penalisation is an efficient alternative to explicitly impose boundary conditions so that the body fitted meshes can be avoided. Penalisation enables ice shedding simulations that take into account ice piece effects on the flow. Level set functions describe the geometry in a non-parametric way so that geometrical and topological changes resulting from physics, and particularly shed ice pieces, are straightforward to follow. The results obtained with the present force formulation are validated against other numerical formulations for circular and square cylinder in laminar flow. The capabilities of the proposed formulation are demonstrated on ice trajectory calculations for highly separated flow behind a bluff body, representative of inflight aircraft ice shedding. © 2012 Copyright Taylor and Francis Group, LLC.


Bergmann M.,French Institute for Research in Computer Science and Automation | Bracco G.,Polytechnic University of Turin | Gallizio F.,Optimad Engineering Srl | Giorcelli E.,Polytechnic University of Turin | And 3 more authors.
MTS/IEEE OCEANS 2015 - Genova: Discovering Sustainable Ocean Energy for a New World | Year: 2015

The aim of this work is to present a numerical approach to solve accurately the coupled dynamic interaction between a floating body and the incoming wave. This floating body is a Wave Energy Converter (WEC) based on the use of gyroscope in order to extract energy from the slope of the sea waves. The hydrodynamic model is based on a Computational Fluid Dynamic (CFD) approach suited to simulate incompressible viscous flows around an arbitrary moving and morphing body. The mechanical model of the energy converter is given by the conservation laws of the flywheel angular momentum equipped with a control algorithm designed for the power optimization. The interaction of the hull of the energy converter with an incoming wave is computed by switching on the effect of the gyroscope and the mooring and both of them. © 2015 IEEE.


Morency F.,École de Technologie Supérieure of Montreal | Beaugendre H.,French Institute for Research in Computer Science and Automation | Gallizio F.,Optimad Engineering S.r.l. | Laurens S.,French Institute for Research in Computer Science and Automation
Modelling and Simulation in Engineering | Year: 2011

We propose to model ice shedding trajectories by an innovative paradigm that is based on cartesian grids, penalization and level sets. The use of cartesian grids bypasses the meshing issue, and penalization is an efficient alternative to explicitly impose boundary conditions so that the body-fitted meshes can be avoided, making multifluid/multiphysics flows easy to set up and simulate. Level sets describe the geometry in a nonparametric way so that geometrical and topological changes due to physics and in particular shed ice pieces are straight forward to follow. The model results are verified against the case of a free falling sphere. The capabilities of the proposed model are demonstrated on ice trajectories calculations for flow around iced cylinder and airfoil. Copyright © 2011 Hlose Beaugendre et al.


Cottet G.-H.,LJK Tour IRMA | Gallizio F.,Polytechnic University of Turin | Gallizio F.,Optimad Engineering Srl | Magni A.,LJK Tour IRMA | Mortazavi I.,French Institute for Research in Computer Science and Automation
American Society of Mechanical Engineers, Fluids Engineering Division (Publication) FEDSM | Year: 2010

The aim of this work is to couple vortex methods with the penalization methods in order to take advantage from both of them. This immersed boundary approach maintains the efficiency of vortex methods for high Reynolds numbers focusing the computational task on the rotational zones and avoids their lack on the no-slip boundary conditions replacing the vortex sheet method by the penalization of obstacles. This method that is very appropriate for bluff-body flows is validated for the flow around a circular cylinder on a wide range of Reynolds numbers. Copyright © 2010 by ASME.


Cottet G.-H.,LJK Tour IRMA | Gallizio F.,Optimad Engineering srl | Magni A.,LJK Tour IRMA | Mortazavi I.,French Institute for Research in Computer Science and Automation
ASME-JSME-KSME 2011 Joint Fluids Engineering Conference, AJK 2011 | Year: 2011

The aim of this work is to couple vortex methods with the penalization methods in order to take advantage from both of them. This immersed boundary approach maintains the efficiency of vortex methods for high Reynolds numbers focusing the computational task on the rotational zones and avoids their lack on the no-slip boundary conditions replacing the vortex sheet method by the penalization of obstacles. This method that is very appropriate for bluff-body flows is validated for the flow around a moving vertical axis turbine for two transitional and turbulent Reynolds numbers. Copyright © 2011 by ASME.

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