Papers by Philippe Guillen
This paper describes a new step in the development of a Computational AeroAcoustics (CAA) process... more This paper describes a new step in the development of a Computational AeroAcoustics (CAA) process whose general long term objective is the numerical prediction of the aerodynamic sound radiated by the airframe of large aircraft at approach, and especially the noise generated by deployed high lift devices such as slats and flaps. The proposed 3-step hybrid process combines CFD (Computational Fluid Dynamics) techniques and acoustic numerical methods, each one being adapted to a particular domain in which specific physical fluid mechanisms are simulated solving an adequate set of equations. In a first step, the nearfield unsteady flow is computed via a compressible three-dimensional LES (Large Eddy Simulation). In a second step, LES-computed perturbations are injected at the inner boundary of a larger domain in which the outward propagation of small perturbations over a non-uniform mean flow is simulated using LEE (linearized Euler equations). In the third and last step, the acoustic field radiated at the external boundary of the LEE domain becomes the entry data of a Kirchhoff integration which provides the noise radiated in the far field. The critical point of the process is the coupling, via an interface, of the LES with the LEE. This process has been carefully studied using analytical fields, an acoustic point source monopole and a convected Eulerian vortex. It has been found that the correct injection of such fields requires severe conditions in terms of space resolution, conditions which are especially difficult to meet for purely vortical fields. In a former study, the LES of the unsteady flow around a NACA0012 airfoil has formed the basis of numerical noise predictions using acoustic integral methods. In the present paper, the same LES is used as a basis for the 3-step CAA process. First results revealed the generation of non-physical noise at the boundary interface where the airfoil's turbulent wake is injected in the Euler domain. Additional tests based on the injection of an analytical vortex suggest that this problem was most probably caused by the under-resolution of the injected vortical structures. This difficulty was not solved, but by-passed by using a LES/LEE interface which did not intercept the airfoil's wake. The final result integrates the three components, including the nearfield LES, the midfield noise propagation using LEE and the farfield noise radiation using the Kirchhoff integral. __________________________________________________ Copyright © 2002 by ONERA. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission INTRODUCTION The general context of this paper is the numerical prediction of the aerodynamic noise generated by the high lift devices HLD, slats and flaps of large airliners, an important contributor to the total radiated airframe noise, especially in approach configuration. It is commonly admitted that the design of new low-noise HLD concepts incorporating specific noise reduction devices, although still relying on necessary experiments, will take growing advantage of the numerical simulation in terms of lower costs and shorter delays, especially considering the spectacular continuing progress of Computational AeroAcoustics (CAA) methods. The problem of the numerical simulation of HLD noise is still beyond the capabilities of complete Direct Numerical Simulation (DNS), so hybrid methods are used in most practical cases. Figure 1 sketches the possible numerical strategies, showing how the nearfield turbulent flow and the farfield noise are computed separately. The idea is to divide the physical space into several domains, in which specific physical mechanisms are simulated using the most adequate set of equations with the cheapest discretization strategy. Computational Fluid Dynamics (CFD) techniques are used to simulate the nearfield flow which contains the aerodynamic noise sources. Available techniques include steady ReynoldsAveraged Navier-Stokes (RANS) computations, in conjonction with stochastic models of the wavenumber-frequency spectrum of the turbulence [1-3], unsteady RANS methods [4-5], and Large Eddy Simulation (LES) [6-9]. This local flow solution has to be coupled to an acoustic numerical technique for the prediction of farfield noise. The most practical formulations are the integral methods such as Lighthill's analogy [7] [10] (including the Ffowcs WilliamsHawkings (FW-H) equation [4, 5, 11, 12]), the Boundary Element Method (BEM) [13] and the Kirchhoff integral. In a former study, the compressible LES of the unsteady flow around a symmetrical NACA0012 airfoil with a blunted trailing edge has formed the basis of airfoil aerodynamic noise predictions. A detailed analysis of the nearfield unsteady flow showed that the local aeroacoustic characteristics were correctly simulated, including the local acoustic field. This suggested to define a control surface around the airfoil, on which the acoustic nature of the pressure field…
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STIN, Oct 1, 1990
A numerical scheme of the MUSCL type used for the numerical simulation of gas flow of different t... more A numerical scheme of the MUSCL type used for the numerical simulation of gas flow of different types around complex configurations is described. Approximate Riemann solvers of the Van Leer, Roc, and Osher types, developed for perfect gas flows are used. These solvers have been extended to non-reactive mixtures of two species and real gas flows by Abgrall, Montagne and
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Journal of Fluid Mechanics, Oct 30, 2007
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Journal of Spacecraft and Rockets, Jul 1, 2001
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The use of the MUSCL approach to simulate blast wave interaction with a stationary object in comp... more The use of the MUSCL approach to simulate blast wave interaction with a stationary object in computational fluid dynamics is addressed. The effects of different limiters and different upwinded flux evaluations when incorporated into the MUSCL approach to compute unsteady flows are studied. The numerical method is described and applied to the blast wave interaction problem with a wedge for different geometric and aerodynamic conditions for which experimental data are available.
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41st Aerospace Sciences Meeting and Exhibit, Jan 6, 2003
Communication to : 41st AIAA aerospace sciences meeting and exhibit, Reno (USA), January 06-09, 2... more Communication to : 41st AIAA aerospace sciences meeting and exhibit, Reno (USA), January 06-09, 2003SIGLEAvailable from INIST (FR), Document Supply Service, under shelf-number : 22419, issue : a.2003 n.17 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc
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Journal of Applied Mechanics, Jul 27, 2011
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Journal of Computational Physics
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Computer Methods in Applied Mechanics and Engineering, Mar 1, 2010
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40th AIAA Aerospace Sciences Meeting & Exhibit, 2002
Communication to : 40th AIAA aerospace science meeting and exhibit, Reno (USA), January 14-17, 20... more Communication to : 40th AIAA aerospace science meeting and exhibit, Reno (USA), January 14-17, 2002SIGLEAvailable from INIST (FR), Document Supply Service, under shelf-number : 22419, issue : a.2002 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc
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Aerospace Science and Technology, 2001
This paper presents a numerical evaluation of the induced roll moment of cruciform missiles by a ... more This paper presents a numerical evaluation of the induced roll moment of cruciform missiles by a turbulent Navier–Stokes solver. The numerical results have been computed with a high resolution implicit upwind scheme. Comparisons with experiments performed at ONERA show a good agreement as well as a decisive improvement over numerical simulations based on Euler equations. Results are presented for subsonic
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This document is issued in order to explain how additional tools may be added to the existing com... more This document is issued in order to explain how additional tools may be added to the existing component parts of the Mhaoteu project and be integrated as part of a coherent software development. Refer to M1.D3 for an overview of the Mhaoteu architecture and look at the other documents on the website for more information.
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In this document, we present the experience of several partners in the process of analyzing and o... more In this document, we present the experience of several partners in the process of analyzing and optimizing an application. This text describes shortly the effort of each partner performed for the MHAOTEU demo workshop held in Barcelona in September 1999. Each partner looked for an application effectively used by academic or industrial end−users (as defined in the MHAOTEU workprogramme), and attempted to optimize that application. This work should not be considered as a description of a Process for Optimizing an Application which is a planned deliverable for the third year. It should be viewed as preliminary investigations on that topic. The text is split in 5 sections, each corresponding to an application. For each application, we provide a short description of the application, performance analysis of the original program and the different steps of the analysis/optimization process.
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Final Summary Report Office National D Etudes Et De Recherches Aerospatiales Paris Direction De L Aerodynamique, Oct 1, 1990
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Aiaa Journal, May 2, 2012
ABSTRACT This paper presents nonspinning-projectile computations with advanced turbulence modelin... more ABSTRACT This paper presents nonspinning-projectile computations with advanced turbulence modeling to demonstrate the relevance of using a hybrid method in projectile simulations. A zonal-detached-eddy simulation methodology is used to improve the base-How prediction without deteriorating the incoming attached flow upstream of the base in the subsonic and transonic regimes. The numerical results are found to compare fairly well with the available experimental wall-pressure data. Both time-averaged and unsteady features are then discussed. Particular attention was paid to the near-wake flowfield and its dependency upon the freestream Mach number. In these calculations, some classical features of massively separated flows, such as the pressure evolution along the base or the wake centerline characteristics, are poorly predicted with the Spalart-Allmaras model. The use of a hybrid method leads to promising results and allows for a physical analysis of the separated flowfield. The flow appears to exhibit selfsimilar properties, even in the recirculation area, independently of the Mach number value in the range of freestream conditions investigated. Moreover, the instability process leading to the shear-laver growth is found to be similar in the range of parameters investigated and is in accordance with previous results concerning the compressibility effects in free shear flows. Finally, base-pressure spectra are reported and compared with axisymmetric base-flow data.
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Aiaa Journal, May 2, 2012
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Papers by Philippe Guillen