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Development of a Hybrid Methodology for the
Numerical Simulation in Aeroacoustics, with
Application to the Mitigation of Aircraft Noise
S. Redonnet
To cite this version:
S. Redonnet. Development of a Hybrid Methodology for the Numerical Simulation in Aeroacoustics, with Application to the Mitigation of Aircraft Noise. Acoustics [physics.class-ph]. AIX-MARSEILLE UNIVERSITE, 2016. �tel-01480728�
Accreditation to Supervise Research (HDR) Dr. Stéphane Redonnet ____________
Aix-Marseille University
Thesis for an Accreditation to Supervise Research
(Mémoire d’Habilitation à Diriger des Recherches)
Development of a Hybrid
Methodology for the Numerical
Simulation in Aeroacoustics, with
Application to the Mitigation of
Aircraft Noise
Stéphane Redonnet
ONERA (French Aerospace Center)
Defended on 10/10/2016
in front of a Jury composed of
D. Juvé, Professor, Ecole Centrale de Lyon
G. Chiavassa, Professor, Ecole Centrale de Marseille
P. Lafon, Senior Research Engineer, EDF
J. C. Robinet, Professor, Dynfluid / ENSAM
M. C. Jacob, Professor, ISAE/SUPAERO
P. Sagaut, Professor, Aix-Marseille University
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TABLE OF CONTENTS
1. FOREWORD ... 4
2. CURRICULUM VITAE ... 5
2.1. Professional Background ... 5
2.2. Academic Degrees and Education ... 5
3. BRIEF OVERVIEW OF PAST ACTIVITIES AND CONTRIBUTIONS ... 6
3.1. Development of the Computational AeroAcoustics (CAA) Solver sAbrinA ... 6
3.2. Application of sAbrinA Solver to the Prediction / Mitigation of Propulsive Noise ... 7
3.3. Application of sAbrinA Solver to the Prediction / Mitigation of Airframe Noise ...10
3.4. Additional (Non R&D) Activities ...13
4. SCIENTIFIC PRODUCTION ...15
4.1. Publications in Peer-Reviewed Scientific Journals ...15
4.2. Other Publications ...16
4.3. Communications in International Peer-Reviewed Conferences with Proceedings ...17
4.4. Communications in International Symposia and Workshops without Proceedings ...20
4.5. Technical Reports ...21
4.6. Institutional Reports ...23
4.7. Miscellaneous ...23
5. ACADEMIC EXPERTISE ...24
5.1. Advisory of PhD Theses and Internships ...24
5.2. Teaching and Training ...25
5.3. Expertise for Funding Programs, Scientific Journals or International Conferences ...25
6. PROJECT SET-UP, COORDINATION AND/OR EXECUTION ...26
6.1. R&D Projects ...26
6.2. Collaborative Network Initiatives ...27
7. SCIENTIFIC AND TECHNICAL REPORT ...28
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7.2. Development of a CAA-based Hybrid Approach: CAA Methodology ...41
7.3. Application of the CAA-based Hybrid Approach to Aircraft Noise Problems: Some Examples based on CAA Calculations ...60
7.4. Development of a Weak-Coupling Procedure for the CAA-based Hybrid Approach ...70
7.5. Application of the CAA-based Hybrid Approach to Aircraft Noise Problems: Some Examples based on CFD-CAA Weakly Coupled Calculations ...82
7.6. Conclusions and Perspectives ...90
Annexes ...94
References ...100
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1. FOREWORD
The present document constitutes my Thesis for an Accreditation to Supervise Research (French so-called Habilitation à Diriger des Recherches). As such, it provides an overview of the research activities I conducted at ONERA (French Aerospace Center) over roughly fifteen years (PhD thesis included). These research activities concerned the numerical simulation in aeroacoustics and its application to the mitigation of aeronautic noise. They were conducted within several frameworks, and led to various achievements of both fundamental and applied natures. The present document, which seeks at synthetizing all these activities and related outcomes, is organized as follows; first, section 2 recalls my educational and professional backgrounds. Then, section 3 provides a succinct - but relatively exhaustive and roughly chronological - overview of my research activities and subsequent contributions, whose resulting scientific production (journal articles, communications, technical reports, etc.) is then listed in section 4. In addition, sections 5 and 6 briefly recall my past actions of academic expertise and project achievement/management, respectively. Then, and unlike section 3 which outlined them succinctly, section 7 delivers a more detailed (though less comprehensive and non-chronological) summary of my research activities and achievements, in the form of a scientific and technical report. Finally, section 8 reproduces some of my publications in peer-reviewed scientific journals, so as to highlight more completely my main contributions to the field of numerical simulation in aeroacoustics and its application to the mitigation of aircraft noise.
But before going further, and because scientific research not only results from solitary investigations but also stems from collective interactions, I would like to express my highest gratitude to those people who directly or indirectly supported my research activities, whether they inspired me by their vivid example, enriched me with their scientific knowledge, endowed me with their technical expertise, or backed me up through our common works; they all had a bigger influence on my research activity than one might suspect.
I respectfully acknowledge the jury members who have done me the honor of examining these research works; there is no greater reward than to be recognized by eminent peers.
I am deeply grateful to Prof. P. Sagaut who, from day one of my PhD thesis until the present HDR examination, constantly inspired, supported and guided me throughout my scientific journey; if I succeeded in balancing the applied aspects of my research with more fundamental ones, the credits primarily go to him.
I feel very much indebted to all the researchers I met and/or worked with during my stay at NASA Langley Research Center, to begin with Dr. M. R. Khorrami, Dr. D. P. Lockard and Dr. M. M. Choudhary (to mention just a few); they are not only the brightest scientists but also the kindest people I had the chance to collaborate with, and working among them for nearly one and a half year left me with a renewed vision of what scientific research should always be.
The same holds for these few industry experts whose scientific excellence comes along with a refreshing authenticity, among whom are Dr. P. Spalart (from Boeing) and Dr. P. Spiegel (from Airbus); sharing with them on scientific matters always rekindled the flame of pure research in me.
I warmly thank these few ONERA colleagues with whom I more intensively collaborated and/or shared over the past few years, to start with Dr. G. Cunha and J. Bulté; they are sharp minds as well as old souls, and teaming up with them made me feel as if I had found my brothers in arms.
I also kindly acknowledge all these ONERA folks with whom I worked all through the years, whether they were PhD or undergraduate students, research peers, heads, or administrative agents; each working experience contributed to shape what became my scientific expertise.
On the same way, I am thankful to these scientists coming from various organizations whom I regularly met through international events, collaborative efforts, transnational projects, national initiatives, and so on; they all had an influence on my vision of our research field.
But above all I thank my beloved wife, Samia; by living beside her, I learn a bit more every day that wisdom is the seal of greatest minds, and that true intelligence does not actually lie in the brain, but rather in the heart.
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2. CURRICULUM VITAE
2.1. Professional Background
2016 Senior Research Fellow at ONERA (French Aerospace Center) Since 2015 Scientific Advisor for the AeroAcoustics Department of ONERA
Since 2011 French National Responsible of the IROQUA Roadmap devoted to the Modelling/Scientific Computing of Aeronautic Noise. Under the auspices of both the DGAC (French General Directorate of Civil Aviation) and the CORAC (Council for Civil Aviation Research), IROQUA is a Collaborative Network that pools all French national Scientific & Technical initiatives to be devoted to the Mitigation of Aeronautic Noise
Since 2011 Independent Expert for various Industry and Academic entities (Airbus, ENSEEIHT, etc.), as Lecturer / Professional Trainer delivering short courses about the Modelling/Scientific Computing of Aeronautic Noise (e.g. Computational AeroAcoustics)
Since 2009 NASA-ONERA Focal Point, as initiator, co-coordinator and/or actor of several NASA-ONERA collaborative actions. With, to date, three NASA-ONERA collaborations (airframe noise prediction, noise absorbing materials, noise source identification) and two NASA supported international pluri-annual workshops (airframe noise prediction, noise source identification) 2009-2010 Visiting Researcher at NASA Langley Research Center
Since 2003 Research Scientist at ONERA, with proficient activity in
- Research and Development, as expert in Computational AeroAcoustics (CAA) and main developer of ONERA’s CAA software sAbrinA, which was (and is still) used within numerous national and international projects devoted to the mitigation of aircraft noise, as well as disseminated within industry and academic entities (e.g. Airbus, CERFACS, Liebher
Aerospace)
- Scientific Publication, as author of approx. 70 papers (articles in international peer-reviewed scientific journals and/or communications in international conferences)
- Project Management, as coordinator and/or work package/task leader of various international, European, French national and ONERA internal projects
- Scientific Expertise, as reviewer for international scientific journals, jury member of several PhD theses, etc.
- Scientific Advisory, as advisor of ONERA PhD theses and internships 1998-2001 Ph.D Thesis, conducted at ONERA (specialty: Computational AeroAcoustics)
1997-1998 Military Service in quality of Civilian Scientist, conducted at Paris VI University for the French
Department of Defense (specialty: ultrasonics, for non-destructive control)
2.2. Academic Degrees and Education
2001 Ph.D in Physics (Mechanics), conducted at ONERA and passed with distinction at
Bordeaux University (France).
1997 Master's Degree in Engineering completed at MATMECA School of Engineers (www.enseirb-matmeca.fr/en) and passed with distinction at Bordeaux University (France). MATMECA is one of the 8 Graduate Schools of Engineers from Bordeaux INP (Public Schools of Engineering). MATMECA trains R&D specialists in complex systems design, delivering a unique multi-disciplinary education in Applied Mathematics, Physics (Mechanics) and Computer Sciences.
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3. BRIEF OVERVIEW OF PAST ACTIVITIES AND CONTRIBUTIONS
The present section delivers a succinct (but relatively exhaustive and roughly chronological) overview of my past research activities and associated contributions. A more detailed (though less comprehensive and non-chronological) summary of these actions and outcomes is indirectly provided in the Scientific and Technical Report of section 7. Please note that all references listed below are excerpted from my scientific production (see section 4).
In respect to the overall problematic of aircraft noise mitigation, my research activity focuses on advanced methods for the numerical simulation in aeroacoustics. Among other things, this activity concerns the development and application of reliable calculation tools, with the twofold objective of i) meeting the practical needs that major stakeholders from the aerospace industry (e.g. aircraft or engine manufacturers, suppliers) may have regarding the noise emission by their products, and ii) answering more fundamental questions of academic entities with respect to the understanding and characterization of the noise physics. Therefore, for nearly fifteen years that I worked at ONERA, I actively contributed to the development of a calculation method for the noise prediction, with that method being relevant from the so-called hybrid approach (i.e. where the stages of noise generation, propagation and radiation are calculated sequentially, as opposed to the direct approach, where they are computed simultaneously). This work consisted in i) the development of the Computational AeroAcoustics (CAA) solver named sAbrinA, ii) its inclusion within a wider calculation chain (through specific couplings with other numerical techniques/tools*), and iii) the subsequent application of all or part of this calculation chain to problems of aircraft noise prediction/mitigation.
3.1. Development of the Computational AeroAcoustics (CAA) Solver sAbrinA
The PhD thesis that I conducted at ONERA over the 1998-2001 timeframe aimed at developing a Computational Aeroacoustics (CAA) solver, so as to numerically simulate realistic noise problems within an aerospace context; first part of such PhD work consisted in a theoretical study and a systematic discrimination of all the various technical elements that were - at that time - proposed in the literature (e.g. theoretical formulations, numerical schemes and possible subsequent optimization, boundary conditions, curvilinear geometries treatment, etc.). Secondly, and on the basis of the technical choices then made, the work consisted in developing an accurate and robust CAA solver, before validating it incrementally on the basis of numerous academic test cases, i.e. offering a direct comparison against analytical or numerical results coming from other approaches (e.g. Boundary Element Method, BEM). Besides these developments per se, more innovative works were achieved with respect the specific topic of boundary conditions, through the development of original techniques allowing to either simulate the free-field radiation (Non Reflecting Boundary Condition, NRBC) or to insert the propagation tool within a wider calculation chain through its interfacing with a noise generation one (e.g. Computational Fluid Dynamics, CFD). All of this resulted in a time-domain, structured, curvilinear CAA solver relying on specific numerical (high-order) schemes and advanced boundary conditions [X-1, CC-1]. This so-called E3P code (which, at that time, was the very first curvilinear CAA solver developed at a French national scale), constituted the early version of the
sAbrinA CAA solver, which was used at ONERA since then.
After my PhD, I managed the transfer of this CAA tool towards ONERA acoustic team, helping the staff to apply it within various prospective studies [RT-1, RT-2, RT-3] (including a hybrid CFD-CAA calculation over an airfoil profile - see section 3.3). In 2003, since most of the code functionalities had then been transferred (by Dr. Terracol) within ONERA’s CFD solver FLU3M so that a synergy can be found between CFD and CAA approaches, I conducted a validation campaign of this sAbrinA (FLU3M) integrated version [RT-4]. I then enhanced the latter solver with a number of specific features (choro-chronic periodicity boundary conditions, duct mode excitation, interfacing with
* such as, regarding the noise generation stage, methods of Computational Fluid Dynamics (CFD) or stochastic techniques (SNGR - Stochastic Noise Generation and Radiation). And, regarding this time the acoustic radiation stage, Integral Methods (IM, e.g. Kirchhoff) or Boundary Element Methods (BEM).
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Integral Methods or Boundary Elements Method, etc.), whereas applying it to various problems of turbomachinery and airframe noises (see sections 3.2 and 3.3). In 2006-2007, since sAbrinA (FLU3M) integrated version had been abandoned for various technical reasons, I took over and pursued the development of sAbrinA initial (PhD thesis) version, first by enhancing it with a multi-domain calculation feature, and then by reintegrating some of the developments made in the integrated version [RT-13]. Later on, I further involved myself in the continuous improvement of this new - and definitive - sAbrinA version, whether it is by i) contributing to the implementation (by Dr. Juvigny, from ONERA/DTIM) of a parallel computing functionality [RT-14], ii) supervising various development and/or integration* tasks (by PhD students or engineers), iii) validating specific developments through academic test cases, or iii) applying the resulting solver to various problems of turbomachinery and airframe noises (see sections 3.2 and 3.3).
In 2007-2008, in response to both a specific need and a formal invitation of Airbus industry, I managed (with Dr. Manoha and Dr. Martin, respectively) the administrative and technical transfers of
sAbrinA solver to Airbus - such transfer being then conducted through several operations of in-situ
installation. In 2009, because of my secondment to NASA (see section 3.3), and after having initially undertaken them, I progressively delegated (to Dr. Le Garrec) all the support tasks required for a proper transfer/use of sAbrinA solver to/by multiple users, refocusing for my part on more fundamental R&D aspects (e.g. integration of sAbrinA solver within an aero-acoustic calculation chain - see section 3.3). Since then, the solver environment has been enhanced with several tools (e.g. software configuration management, online documentation, non-regression tests) whose purpose is to ease its continuous development/application by a still larger audience.
To date, sAbrinA solver has become a key tool for the numerical simulation in aeroacoustics; constituting the leading code of the so-called LAURA aeroacoustics computing platform of ONERA,
sAbrinA spearheads most studies involving complex aeroacoustics problems. It was - and still is -
widely used at ONERA, whether it is within European or transnational projects†, PhD theses‡ or internships, international collaborations (with, to date, no less than six cooperative efforts with NASA§), and so on. This solver is also used out of ONERA, for instance at Airbus, where it is employed as both a reference tool (e.g. validation/performance studies of alternative acoustic solvers) and a prospective means (e.g. acoustic propagation in harsh environments**). Finally, this solver is recognized internationally, thanks to the numerous publications in scientific journals and communications in international conferences it led to, as well as through the role it plays within national and international cooperative efforts that seek at improving the numerical simulation tools in aeroacoustics (workshops, benchmarks - see section 3.3).
All the above explains why, over the last decade, sAbrinA solver has generated a large volume of R&D activities (through industry contracts, in particular), as well as it has led to a consequent scientific production - allowing thus ONERA i) to reinforce its leading position on the topic of numerical simulation and aircraft noise mitigation, ii) to strengthen its relations with all concerned stakeholders (e.g. industries, research centers), and ii) to gain in recognition at an international scale.
3.2. Application of sAbrinA Solver to the Prediction / Mitigation of Propulsive Noise
Over the 2003-2008 timeframe, and besides the development/validation efforts recalled above, my work consisted in an intensive application of sAbrinA solver to propulsive noise problems.
* such as, for example, that of a time-domain impedance boundary condition simulating the noise absorbing materials [RT-15].
†
European Projects NACRE, VITAL, OPENAIR, CRESCENDO, NINHA, JERONIMO, ENOVAL, ADEC,
ASPIRE, etc. / (Trans)National projects SEBU, LNA2, AMBIANCE, JENOM, AEROCAV, AITEC2, etc.
‡ PhD theses by R. Guénanff, G. Desquesnes, D. Mincu, V. Clair, A. Lafitte, G. Reboul, G. Cunha, M. Escouflaire, Y. Pene, S. Bousabaa, etc.
§
With three NASA-ONERA Collaborations (themes: Airframe Noise, Acoustic Liners, Noise Localization) and three NASA-supported international Workshops (themes: Airframe Noise, Noise Localization, Broadband Fan Noise).
** such as, for example, the numerical assessment of aft fan noise emissions by an exhaust operating in supersonic conditions.
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3.2.1 Numerical Characterization of the Fan Noise by Turbofans
As part of various national or transnational projects (e.g. SEBU, LNA2, AMBIANCE) that were conducted in close collaboration with Airbus, I first worked on the numerical characterization of the aft fan noise emitted by turbojets [RT-5 to -9, RT-11, RT-12].
Although primarily of applicative nature, this work turned out to also be prospective, since - at that time - such kind of propulsive noise problematic had been rarely handled by the means of CAA. Therefore, my work first consisted in development and validation actions, which focused on either the improvement of the sAbrinA solver itself (e.g. implementation of specific boundary conditions techniques*, of parallel computing features, etc.), the reinforcement of the overall methodology (i.e. proper handling of hydrodynamic instabilities rising from the jet shear layers, etc.), or the development of specific pre- and post-treatment tools (e.g. CAA mesh generation, CFD → CAA interpolation of the background mean flow, mid- to far-field extrapolation via a Kirchhoff-type Integral Method, etc.). To this end, I developed several tools† and derived various procedures that I then applied to the considered configurations - establishing thus the methodological guidelines that, since then, were adopted by ONERA acoustic team for all subsequent activities associated with this particular thematic of propulsive noise prediction through CAA means.
My application of sAbrinA solver to the problematic of aft fan noise emissions by turbojet engines resulted in various outcomes, of either phenomenological or methodological nature; from a phenomenological perspective, these actions first allowed me to highlight the refraction effects that, being induced by the jet shear layers, alter the propagation and the radiation of the aft fan noise - and, this, in a much more severe way that what may be encountered for its the upstream component, which is emitted by the air inlet. On this stage, I more particularly highlighted the great variability of these refraction effects, which depend not only on thermodynamic conditions (mean flow) but also on the acoustic excitation characteristics (duct modes). Later on, still within the same frameworks (AMBIANCE project), I studied the internal acoustic installation effects, namely those that are induced by the complex nature of both the exhaust geometry and its flow, primarily because of the presence of pylon and bifurcations. Here again, dedicated investigations allowed me to highlight the importance of these effects onto the downstream fan noise signature, as well as to explore their underlying physical mechanisms (modal redistribution induced by geometry and flow heterogeneities, etc.) [RT-12]. Besides dedicated communications [CC-13, CC-15], this particular study led to a publication in the
AIAA Journal [AJ-4]. In the wake of this work, and using all methodological elements the latter had
led to, my colleagues of ONERA acoustic team and I then performed a larger demonstrative calculation (exhaust installed under a swept-wing [RT-17]), which allowed extending such investigation to the external acoustic installation effects, that is, those resulting from the integration of the turbofan within an aircraft architecture. From a methodological point of view, these works clearly demonstrated that one shall preferably make use of a high-fidelity tool for simulating realistic problems of propulsive noise, since only a highly accurate solver (such as sAbrinA) can restitute properly the acoustic propagation within complex environments (including solid obstacles and/or heterogeneous flow, etc.). These works also led to the acquisition of key skills, which allowed ONERA to position itself favorably on this thematic of propulsive noise prediction through CAA means, generating a substantial and sustained R&D activity. The latter activity, which was conducted through various frameworks (e.g. national or European projects, PhD thesis by Reboul), allowed to further pursue these investigations, as well as to extend them to other noise components (turbine noise, broadband fan noise, etc.) [AJ-2, CC-29]. To date, such activity is still very vivid, whether it is within the framework of recent European and national projects‡, or ONERA internal actions.
* e.g. choro-chronic periodicity, modal excitation, etc.
† Some of these tools also served in other frameworks, such as the Kirch3D code (Kirchhoff-based Integral Method, IM) which was subsequently used in various studies of either fundamental (PhD theses by D. Mincu and F. Mery) or applicative (European projects) nature, before it was refurbished into an IM tool (MIA solver, resulting from the merging of ONERA’s KIF and Kirch3D codes) that was then integrated within ONERA’s AeroAcoustic Simulation platform LAURA.
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3.2.2 Numerical Investigation of the Propulsive Noise Mitigation to be possibly offered by Novel Aircraft Concepts or Innovative Powerplant Architectures
Over the same 2003-2008 timeframe, still within the framework of national projects (SEBU, LNA2) and using the same CAA tools, I also investigated the impact of external installation effects onto the aft fan noise (and, more prospectively, onto the fine scale turbulence component of jet noise). The purpose here was to numerically investigate how propulsive noises could be mitigated through passive reduction concepts relying on innovative aircraft configurations with unconventional architectures.
First, in 2003, I numerically conducted a prospective study of the so-called semi-buried nozzle concept [RT-5 to -9], which helped highlighting the acoustic benefit offered by a flying wing type of aircraft configuration, thanks to the shielding by the airframe of propulsive noises (fan + turbine and, to a lesser extent, jet) [CC-6 CC-10]. Subsequently, using the numerical tools developed and the methodological know-how acquired, my colleagues of ONERA acoustic team pursued such study further within the framework of NACRE European project, investigating this problematic under the perspective of the upstream fan noise emitted by a semi-buried air intake.
Secondly, over the 2004-2006 timeframe (LNA2 project), I numerical investigated another innovative concept of passive reduction for fan/turbine noises, namely the so-called RFN (Rear Fuselage Nacelle) configuration by Airbus - which relies on locating the engines at the rear of the aircraft, whose U-shape tail can then shield part of the propulsive noise emissions. This work, which led to a dedicated publication in the AIAA Journal [AJ-3] and several communications in international conferences [CC-9, CC-10, CC-35, CC-36, CC-38], resulted in various outcomes; first, from a phenomenological point of view, it demonstrated the benefit effectively offered by the RFN concept regarding the mitigation of engine noise signature - a thing that, since then, has been confirmed thanks to dedicated numerical and experimental studies (NACRE European project) [CC-26]. From a more methodological point of view, this work offered a unique opportunity to early apply and validate within a real-life context a CAA-CAA strong coupling functionality (chimera approach) that had been developed in another framework (PhD thesis by G. Desquesnes), and that was used in this study so as to ease its achievement. Last but not least, this work also led to the development and the application of a CAA-BEM weak-coupling technique, through the interfacing of sAbrinA and ACTIPOLE (Airbus) solvers. Such achievement, which constituted an additional step towards the development of a comprehensive aeroacoustics calculation platform (i.e. allowing to handle highly complex configurations), has since been applied and/or duplicated (sAbrinA-BEMUSE interfacing) by my colleagues of ONERA acoustic team, this being performed in the framework of subsequent studies (e.g. NACRE European project).
Still concerning innovative concepts of passive reduction for the propulsive noise, and following what is done for turbofan inlets (negative scarf intake), I then proposed and conducted a numerical investigation of the advantages to be potentially offered by a scarfed exhaust onto the aft fan noise emission (through its possible deflection by the modified geometry and flow). Conducted in 2005 within an ONERA internal project, this prospective study allowed highlighting the effective acoustic benefit provided by such a concept [CC-9], which I then proposed to assess more completely through a dedicated activity in the European project OPENAIR - such activity being then pursued by my colleagues of ONERA acoustic team using the same tools (sAbrinA, Kirch3D), and confirming very clearly the positive conclusions initially drawn [CC-29].
3.2.3 Numerical Modeling and Characterization of Propulsive Noise Reduction Devices based on Acoustically Absorbing Materials
Still regarding techniques of passive reduction for the fan/turbine noise, since 2006, I actively involved myself into the development and implementation within sAbrinA solver of an advanced impedance boundary condition - which is required for a CAA solver of time-domain nature can restitute the acoustic attenuation effects induced by noise absorbing materials (or acoustic liners).
Such activity was primarily conducted within the framework of PhD theses (G. Delattre and M. Escouflaire) and internships (G. Delattre), which I advised or helped advising [CC-14, CC-37, CC-38]. The activity was also held through specific integration and/or application tasks [RT-15, RT-16], which were conducted within various frameworks, being achieved by myself or by engineers under my supervision. In particular, over the 2010-2011 timeframe, I numerically investigated the potential
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benefit offered by the use of noise absorbing materials within engine exhausts [CC-36, CC-27], which allowed to not only apply to an industrial case all the developments made hitherto, but to also numerically investigate specific points of the physics underlying acoustic liners (e.g. rupture of impedance, etc.).
In 2011, besides advising a PhD thesis specifically dedicated to this topic (PhD thesis by M. Escouflaire), I initiated and coordinated (with Dr. F. Simon, from ONERA/DMAE) the setting up of a NASA-ONERA collaboration devoted to the experimental and numerical characterization of noise absorbing materials. Initially agreed for a period of one year and a half, this collaboration was then extended for two additional years. Relying on common experimental tests and numerical simulations jointly conducted by ONERA and NASA, this bilateral collaboration consisted in comparing / cross-validating the experimental means and numerical techniques used from both sides, with respect to the characterization of noise absorbing materials (experimental measurements and eduction, numerical modeling and characterization, etc.). Concerning more particularly the numerical actions by ONERA - which I was in charge of, simulations concerned academic test cases (NASA’s GFIT - Grazing Flow Impedance Tube), as well as industrial applications (aft fan noise emission by a turbofan exhaust equipped with noise absorbing panels).
Besides all the communications they led to [CC-14, CC-37, CC- 38, CC-36, CC-27], all these works shall soon result in a dedicated publication [AJ-17].
Finally, still regarding such problematic of aircraft noise mitigation through passive reduction devices, I recently set-up a dedicated ONERA research project*; spanning three years and involving approximately fifteen engineers from four ONERA departments, this project aims at enhancing ONERA capacities in terms of theoretical modeling, numerical simulation and experimental characterization of noise absorbing materials. Among other things, this project will consist in i) equipping ONERA’s CFD solver elsA with specific features enabling the proper modeling of noise absorbing materials (e.g. a time-domain impedance boundary condition such as the one previously developed for sAbrinA solver), ii) validating these features by comparison against dedicated experiments and high-fidelity numerical simulations (DNS) iii) applying the resulting tool to realistic problems of airframe and propulsive noises (including a high-lift wing and a supersonic exhaust, respectively), as well as iv) investigating further some specificities of noise absorbing materials (e.g. rupture of impedance, hydrodynamic instabilities, etc.).
3.3. Application of sAbrinA Solver to the Prediction / Mitigation of Airframe Noise
Besides the above summarized activities devoted to the problematic of propulsive noise, I also actively involved myself into the further development and continuous improvement of the CAA approach with respect to airframe noise problems.
3.3.1 Numerical Characterization of the Airframe Noise by High-Lift Devices, Cavities or Landing Gears
First, through my involvement into the advisory of internship (D. Mincu) or PhD theses (R. Guenanff, G. Desquesnes) works, I took part in various actions aiming at numerically characterizing the slat noise emitted by an in-flight high-lift wing [CC-5, CC-13]. This was achieved through hybrid calculations relying on decoupled CFD and CAA computations (the CAA step being carried out using equivalent elementary noise sources calibrated according to the characteristics of the unsteady CFD solution), such hybrid calculations being then possibly far-field extrapolated via an Integral Method (IM) using the Kirch3D code I had developed earlier.
Then, through the advisory of a PhD thesis (D. Mincu), I focused on the numerical prediction of aerodynamic noise by cylindrical cavities which, located in many places of the airframe, may generate high levels acoustic whistles when an aircraft is flying. This work consisted of classical CFD-IM hybrid calculations [CC-19, CC-23], whose IM stage also relied on the Kirch3D code.
In 2008, I initiated and then set-up (with Dr. Manoha) a dedicated NASA-ONERA collaboration, so as to improve the numerical simulation techniques used from both NASA and ONERA sides for
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simulating the aerodynamic noise. Initially agreed for three years, this collaboration was subsequently extended twice, for a total of four additional years. Being composed of various actions (PhD thesis by F. Houssen, internships, internal projects, etc.) and focusing both on academic test cases (one or two cylinders in a cross flow) and on realistic problems (in-flight nose landing gears by Airbus and Gulfstream), this collaborative effort provided a unique opportunity to compare the methods and tools used either by ONERA (elsA or CEDRE, KIM codes) or by NASA (CFL3D or FUN3D, FWH3D codes) for achieving CFD-IM hybrid calculations. This effort also offered to go a step further than the latter classical CFD-IM hybrid approach, through the development of an advanced CFD-CAA hybrid approach (see section 3.3.2 below) – a thing in which I involved myself more particularly, during a secondment of nearly one year and a half that I conducted at NASA Langley Research Center (LaRC). All these NASA-ONERA collaborative works led to many communications in international conferences (several of which I co-authored [CC-30, CC-32, CC-33, CS-11]), as well as a journal publication that I co-authored with NASA researchers [AJ-11].
3.3.2 Development and Application of a CFD-CAA Hybrid Approach
My most valuable contribution to the problematic of airframe noise is the development of CFD-CAA coupling techniques, which aim at linking unsteady aerodynamic CFD solvers (e.g. elsA) with acoustic propagation CAA tools (e.g. sAbrinA).
Indeed, as stated above, during my PhD thesis I developed an original interfacing (or surface weak-coupling) technique [X-1, CC-1], which was then successfully applied (by Herrero et al.) to a typical airframe noise problem (trailing edge noise by a NACA 0012 airfoil). This was achieved via a CFD-CAA-IM twofold hybrid calculation, which - at that time - was a world premiere, and consequently led to many communications [CC-4, CC-3, CS-3, 5 & 6] as well as a journal publication [AJ-1]. Later on, the CFD-CAA hybrid approach and underlying interfacing technique were applied to other problems by my colleagues from ONERA acoustic team, this being performed within various frameworks (PhD thesis by R. Guénanff, national projects, etc.).
In 2006, with the view of making the CAA-based hybrid approach compatible with other types of couplings (e.g. SNGR-CAA, for which the noise generation step is synthesized via a stochastic method rather than computed by CFD), I investigated the so-called volumetric coupling technique (i.e. relying on a source term). Hence, I proposed an original source term formulation [CC-17] that I then numerically assessed on the basis of academic test cases (e.g. co-rotating vortices), before it was applied to a realistic problem of airframe noise (trailing edge noise by the slat of a high-lift wing) [CC-17]. I pursued this work in the margins of an industry-supported PhD thesis (by M. Omaïs) that I advised (with Dr. Caruelle, from Airbus), and whose objective was to develop a SNGR-CAA hybrid method for predicting the jet mixing noise by turbojets. Among other things, this PhD thesis led to the development of a SNGR module (sArA code [CC-20]), which was then further improved (PhD thesis by A. Laffite) and incorporated within sAbrinA environment – allowing then to perform SNGR-CAA hybrid calculations of various real-life problems of noise emission (by a slat cove [CC-25], by a confined jet, etc.).
In 2009-2010, during my secondment to NASA/LaRC, I worked on relaxing some of the constraints weighting on the CFD-CAA surface weak-coupling technique initially proposed during my PhD thesis. In particular, with the view of making it applicable to problems involving acoustic installation effects (for which numerical simulation via a CAA-based hybrid method is more particularly appropriate), I developed the so-called Non Reflecting Interface (NRI), which is an innovative interfacing technique of non-reflective (i.e. numerically transparent) character [CC-28]. Together with NASA scientists, I then applied such improved CFD-CAA surface coupling technique to a realistic problem of aerodynamic noise including installation effects (i.e. a pair of cylinders flown in the QFF anechoic wind tunnel of NASA/LaRC) [CC-32]. The resulting CFD-CAA hybrid calculations were achieved by weakly coupling NASA’s CFL3D solver with ONERA’s sAbrinA code, allowing to not only further validate the NRI technique with respect to a real-life application, but to also finely characterize the acoustic installation effects that may had weighted on the associated experimental campaign, because of the QFF experimental setup (solid appendages of the test apparatus, confinement of the facility jet, etc.). This study has been extensively documented through dedicated communications [CC-28, CC-32], journal articles [AJ-11, AJ-9], or reports (NASA
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Technical Memorandum [RT -22], ONERA report [RT-19]), some of which were jointly written with NASA scientists.
In 2011, on the invitation of its manager (Dr. Choudhari, from NASA), I joined the coordination team of the BANC (Benchmark for Airframe Noise Computations), an international and multi-annual workshop that is promoted by NASA and supported by AIAA (American Institute of Aeronautics and Astronautics), so as to assess and improve the numerical techniques developed and used worldwide for simulating aerodynamic noise. As such, I actively participated in defining the test cases of BANC category 8, whose objective is to benchmark the various numerical approaches (e.g. IM, CAA, BEM) to be possibly used for acoustically exploiting unsteady CFD calculations [CC-40, CC-43]. Recently, I proposed and managed the inclusion within this Category 8 of a test case derived from some of the works I conducted regarding the numerical prediction via CFD-CAA hybrid calculations of the noise emission by a nose landing gear (see section 3.3.3) [CC-39]; such test case offered an unique opportunity to compare on the same basis the various hybrid approaches (IM, CAA, CFD-BEM) used for the prediction of aerodynamic noise by several research centers (ONERA, NASA, JAXA, Old Dominion University, Campinas University, etc.), leading to a dedicated joint communication [CC-43].
3.3.3 Optimization of the CFD-CAA Hybrid Approach
When back from the US, I further improved the CFD-CAA hybrid approach, whether it is through personal research actions or via the advisory of a dedicated PhD thesis (by G. Cunha).
First, over the 2010-2013 timeframe, G. Cunha and myself studied from a theoretical point of view some of the fundamental constraints weighting on any hybrid approach, such as the signal degradation to which any unsteady CFD dataset may be subjected, when manipulated (i.e. sampled and/or interpolated in space and/or time) in order to be acoustically exploited (either via IM or CAA). This study allowed determining specific criteria as well as establishing subsequent guidelines for a better preservation of unsteady CFD data during both their storage and their acoustic exploitation. This work, which led to two dedicated journal articles [AJ-5, AJ-12], provided some key insights that were since further explored and/or applied by some of my colleagues from ONERA acoustic team, regarding alternative hybrid approach (CFD-IM) and/or applications (jet noise, landing gear noise).
Following this initial study, we then worked on relaxing the constraints weighting on such signal preservation, mostly by proposing innovative optimization processes – whether the latter optimization processes concern interpolation techniques (which led to the so-called Interpolation By Part - IBP) or ii) derivation/filtering schemes (which led to the so-called Intrinsically Optimized Finite Difference – IOFD schemes). All these outcomes were extensively documented via no less than three journal articles [AJ-6, AJ-8, AJ-10], as well as various communications [CC-31, CC-34, CC-35].
All these innovative solutions allowed us to optimize the NRI-based CFD-CAA hybrid approach, before applying it to a real-life problem of noise emission by a nose landing gear*. This resulted in CFD-CAA hybrid calculations (elsA-sAbrinA weakly-coupled computations [CC-39]) which, in addition to compare favorably against the available experimental results, offered to numerically investigate the acoustic installation effects that been possibly weighted on the associated experiment, because of the anechoic facility jet flow (a thing that was beyond the capacities of the CFD-IM hybrid approach which had been used, otherwise). On this stage, it is worth noticing that these CFD-CAA hybrid calculations benefited directly from the IOFD optimized schemes mentioned earlier, which use offered to greatly lighten the CAA mesh - a thing without which the calculation CPU cost would have been far too prohibitive. This work, whose excerpts were documented through various communications (e.g. [CC-39, CC-35]) or journal articles ([AJ-9, AJ-7]), shall soon lead to a dedicated publication [AJ-13].
Lately, the NRI-based CFD-CAA hybrid approach has been applied by my colleagues from ONERA acoustic team to other types of real-life noise problems involving aircraft installed configurations, such as i) the noise radiated by a Contra-Rotating Open Rotor (CROR) turboprop integrated within an aircraft architecture (NINHA European project) or ii) that by the jet of a Ultra-High By-Pass Ratio (UHBR) turbofan located nearby a high-lift wing (JERONIMO European project).
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Finally, the NRI-based CFD-CAA hybrid approach is currently being extended further for an application to noise problems induced by spacecraft (i.e. the numerical prediction of acoustic loads by a lifting-off space launcher, with the latter installed within its launchpad environment). These actions, which aim at meeting the needs of CNES (French Spatial Agency) for what concerns its next generation launcher Ariane VI, are currently conducted by me within the framework of a dedicated ONERA research project* [RT-22].
3.3.4 Numerical Characterization of the Acoustic Installation Effects by Anechoic Facilities
In the wake of the NASA-ONERA collaborative actions conducted during my secondment to NASA/LaRC, and on the invitation of NASA scientists to do so, I pursued the R&D activities devoted to the numerical characterization of acoustic installation effects to possibly occur within anechoic wind tunnels; a first action, which was conducted together with Dr. D. Lockard (NASA) consisted in extending the numerical study performed over the Tandem Cylinders (TC) configuration (see above), with the view of extrapolating such early assessment of acoustic installation effects by NASA’s QFF anechoic facility to the airframe noise experiments that are typically conducted there (e.g. higher frequency sources) [CC-41]. A second action, which was this time conducted together with J. Bulté (ONERA), sought at characterizing the sole refraction effects induced by jet flows of typical anechoic wind tunnels (e.g. NASA’s QFF or ONERA’s CEPRA19 facilities). Besides the phenomenological insights they led to (e.g. physics of refraction effects), these two research actions allowed to i) highlight the actual limitations weighting on the analytical corrections (e.g. Amiet’s model) that are commonly applied to the acoustic measurements performed in anechoic wind tunnel, as well as ii) to demonstrate how such limitations can be lifted by an appropriate use of advanced numerical techniques (e.g. Computational AeroAcoustics - CAA, Geometrical Acoustics - GA). Note that, besides leading to dedicated communications [CC-41, CC-44 & CC-42] (and a possible journal publication [AJ-16]), such CAA-based numerical investigations of the acoustic installation effects by open jet wind tunnels inspired more or less directly similar or complementary research actions, which were carried out by my colleagues of ONERA acoustic team within various frameworks (PhD theses by D. Mincu and I. Bennaceur, GARTEUR transnational project, etc.).
Finally, still along with J. Bulté (ONERA), I am currently working on extending and/or applying to within a numerical context the microphone array methods that are commonly used in experiments for localizing noise sources. This work first led to a successful exploitation by two array techniques† of the CFD-CAA hybrid calculations that had been previously performed for numerically simulating the noise emission by an in-flight nose landing gear (see above). Such effort, which was recently documented through a communication [CC-45] (submitted for publication [AJ-14]), paved the way for a more systematic use of array methods within a numerical context, through the post-processing of aeroacoustics simulations (whether the later rely on CFD-CAA or CFD-IM hybrid calculations); at ONERA for instance, in the wake of this particular effort, several research actions were initiated within various frameworks‡, so as to further assess and/or apply such methodology to other problematics (jet noise by either an aircraft-integrated UHBR engine or a space launcher within its launchpad environment, etc.). On the same way, and on the invitation of its manager (Dr. Bahr, from NASA), we derived from this particular effort a dedicated test case for the so-called Array Methods workshop, which is an international collaborative effort that aims at improving the array method techniques used worldwide.
Here, it is worth noticing that in the wake of all these efforts, a dedicated NASA-ONERA collaboration is currently discussed and shall soon be initiated, so as to pursue further the numerical characterization via CAA of NASA’s QFF facility, with respect to its noise localization capabilities.
3.4. Additional (Non R&D) Activities
In 2007, I coordinated the set-up of a large-scale project (gathering 18 entities - Industries, Research Centers, Universities, SMEs), whose objective was to characterize via numerics and experiments the
* AJIL research project
† Deconvolution Approach for Maps of Acoustic Sources (DAMAS) and Classical Beam Forming (CBF) ‡ JERONIMO European Project, AJIL ONERA Research Project, PhD thesis by S. Bousaaba
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noise emission by a CROR-powered aircraft, and whose proposal [X-2] was submitted to the 1st call of the European 7th Framework Program (FP7).
Since 2011, I regularly provided lectures for industry and academic entities (e.g. Airbus,
ENSEEIHT), delivering short courses about aeroacoustics hybrid methods and their application to the
aircraft noise mitigation.
In 2011, I was appointed French national responsible for the Numerical Simulation Roadmap of IROQUA network (which, under the auspices of both the DGAC* and the CORAC†, constitutes a unique collaborative network that pools all French national scientific initiatives devoted to the mitigation of aircraft noise). As such, and along with IROQUA’s program director (Dr. Leylekian, from ONERA), I initiated and coordinated a national consultation phase between industries, research centers and universities, which permitted to take stock of the current resources and needs, in terms of national capabilities for the numerical simulation of aircraft noise. These insights, which were documented trough a dedicated report [RT-21], shall now enable all concerned stakeholders to build an ambitious framework project, so as to improve at a national scale the numerical techniques and tools devoted to the mitigation of aircraft noise.
As indicated in several places above, since 2008, I initiated and/or joined several collaborative efforts between NASA and ONERA, whether the latter efforts concerned dedicated NASA-ONERA collaborations or supported international workshops. Thanks to this liability about NASA-ONERA collaborative actions, and on the invitation of my hierarchy, I recently involved myself into the set-up of a potential framework agreement between NASA and ONERA. The latter’s objective is to mutualize part of the fundamental research efforts to be deployed from both sides over the next 10 years, regarding the mitigation of civil aircraft noise.
In 2015, along with Dr. Blacodon (ONERA), I was appointed Scientific Advisor of ONERA’s aeroacoustics department (DAAC). As such, and with respect to all computational activities (their experimental counterpart being represented by Dr. Blacodon), I represent the DAAC within the Scientific Council of ONERA’s Fluid Mechanics and Energetics (MFE) branch. Among other things, the latter council helps in orientating and organizing all fundamental R&D activities conducted at ONERA, for instance by selecting / monitoring the various initiatives (research projects, PhD theses, etc.) to be preferably supported through ONERA internal fundings.
In 2016, I was appointed Senior Research Fellow (so-called “Maitre de Recherche 1”) of ONERA. As such, and besides my usual activities for enhancing ONERA’s scientific outreach (via journal publications, PhD advisory, teaching, etc.), I am likely to regularly join dedicated committees focusing on the evaluation and the orientation of ONERA’s research activities.
*
French General Directorate of Civil Aviation. † French Council for Civil Aviation Research.
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4. SCIENTIFIC PRODUCTION
Below is an exhaustive list of my scientific production*, which is composed of 15 publications / submissions in peer-reviewed scientific journals, more than 55 communications in international conferences (among which 35 AIAA papers), more than 25 reports, and a few miscellaneous references (e.g. chapters of book).
4.1. Publications in Peer-Reviewed Scientific Journals
4.1.1 Articles Published in Peer-Reviewed Scientific Journals
[AJ-1] M. Terracol, E. Manoha, C. Herrero, E. Labourasse, S. Redonnet and P. Sagaut, “Hybrid Methods for Airframe Noise Numerical Prediction”, Theoretical and Computational Fluid Dynamics, Vol. 19 (3), July 2005.
[AJ-2] C. Polacsek, S. Burguburu, S. Redonnet and M. Terracol, “Numerical Simulations of Fan Interaction Noise using a Hybrid Approach”, AIAA Journal, Vol. 44 (6), June 2006.
[AJ-3] S. Redonnet, G. Desquesnes, E. Manoha and C. Parzani, “Numerical Study of Acoustic Installation Effects with a CAA Method”, AIAA Journal, Vol. 48 (5), May 2010.
[AJ-4] S. Redonnet and Y. Druon, “Computational AeroAcoustics of Realistic Co-Axial Engines”,
AIAA Journal, Vol. 50 (5), May 2012.
[AJ-5] G. Cunha and S. Redonnet, “On the Signal Degradation Induced by the Interpolation and the Sampling Rate Reduction in Aeroacoustics Hybrid Methods”, International Journal for Numerical
Methods in Fluids, Vol. 71 (7), February 2013.
[AJ-6] G. Cunha and S. Redonnet, “On the Effective Accuracy of Explicit Spectral-Like Optimized Finite-Difference Schemes for Computational Aeroacoustics”, Journal of Computational Physics, Vol. 263, April 2014.
[AJ-7] S. Redonnet, “Aircraft Noise Prediction via AeroAcoustics Hybrid Methods - Development and Application of ONERA Tools over the last Decade: Some Examples”, Aerospace Lab Journal, Vol. 7, June 2014.
[AJ-8] G. Cunha and S. Redonnet, “A Novel Optimization Technique for Explicit Finite-Difference Schemes with Application to AeroAcoustics”, International Journal for Numerical Methods in Fluids, Vol. 78 (4), June 2015.
[AJ-9] S. Redonnet and G. Cunha, “An Advanced Hybrid Method for The Acoustic Prediction”,
Advances in Engineering Software, Vol. 88, October 2015.
[AJ-10] G. Cunha and S. Redonnet, “Development of Optimized Interpolation Schemes with Spurious Modes Minimization”, International Journal for Numerical Methods in Fluids, Vol. 80 (2), January 2016.
[AJ-11] S. Redonnet, D. P. Lockard, M. R. Khorrami and M. M. Choudhari, “The Non Reflective Interface: An Innovative Forcing Technique for Computational Acoustics Hybrid Methods”,
International Journal for Numerical Methods in Fluids, Vol. 81 (1), May 2016.
*
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[AJ-12] G. Cunha and S. Redonnet, “On the Spurious Mode Generation Induced by Spectral-Like Optimized Interpolation Schemes Used in Computational Acoustics”, Communication in
Computational Physics, 2016 (in press, DOI: 10.4208/cicp.060515.161115a).
4.1.2 Articles under Consideration for Publication or in Preparation for Submission to Peer-Reviewed Scientific Journals
[AJ-13] S. Redonnet, S. Ben Khelil, J. Bulté and G. Cunha, “Numerical Characterization of Landing Gear Aeroacoustics using Advanced Simulation and Analysis Techniques”, submitted to Journal of
Sound and Vibration, October 2016.
[AJ-14] J. Bulté and S. Redonnet, “Landing Gear Noise Sources Identification through an Application of Array Methods to Experimental and Computational Data”, submitted to AIAA Journal, October 2016.
[AJ-15] G. Cunha and S. Redonnet, “On the use of Dynamic Mode Decomposition in Computational AeroAcoustics”, on the point to be submitted to Journal of Computational Physics.
[AJ-16] S. Redonnet and J. Bulté, “Numerical Characterization of Refraction Effects by Jet Flows in Open Wind Tunnels”, in preparation for submission to Journal of Sound and Vibration.
4.2. Other Publications
4.2.1 Chapters in Specialized Magazines or Books
[AX-1] S. Redonnet and E. Manoha, “Numerical Simulation of Turbojet Aft Fan Noise*” in
Techniques de l’Ingénieur, 2009. As a scientific review for the general public, the French magazine
Techniques de l’Ingénieur has established itself as the most important S&T documentary collection in
France (see www.techniques-ingenieur.fr).
[AX-2] E. Manoha, S. Redonnet and S. Caro, “Computational AeroAcoustics”, in “Acoustics and Noise” by X. Zhang, Chapter of Encyclopedia of Aerospace by R. Blockley and W. Shyy, Vol. 1, part 28, Wiley & Sons, 2010.
4.2.2 Excerpts in Special Issues of Journal of Sound and Vibration (JSV)
[AX-3] S. Redonnet, G. Desquesnes and E. Manoha, “3D Numerical Simulations of Acoustic Installation Effects onto the Aft Fan Noise of a Turbofan Engine” in “Aeroacoustics Research in Europe – The CEAS/ASC Report on Highlights 2006” by S. Caro, special issue of Journal of Sound
and Vibration, Vol. 304, July 2007.
[AX-4] S. Redonnet, G. Desquesnes and E. Manoha, “Numerical Study of Acoustic Installation Effects through a Chimera CAA Method” in “Aeroacoustics Research in Europe - The CEAS/ASC Report on Highlights 2007” by H. H. Brouwer and S. W. Rienstra, special issue of Journal of Sound
and Vibration, Vol. 318 (4&6), December 2008.
[AX-5] S. Redonnet, D. Mincu and E. Manoha, “3D Numerical Simulations of the Aft Fan Noise Emitted by a Realistic Turbofan Engine” in “Aeroacoustics Research in Europe - The CEAS/ASC Report on Highlights 2009” by D. Casalino, special issue of Journal of Sound and Vibration, Vol. 329 (22), October 2010.
[AX-6] S. Redonnet, D. P. Lockard, M. R. Khorrami and M. M. Choudhari, “CFD-CAA Coupled Calculations of a Tandem Cylinder Configuration to Assess Facility Installation Effects”, in “Aeroacoustics research in Europe: The CEAS/ASC report on Highlights 2011” by A. McAlpine and R. J. Astley, special issue of Journal of Sound and Vibration, Vol. 331, October 2012.
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Computational Aeroacoustics”, in “Aeroacoustics research in Europe: The CEAS/ASC report on Highlights 2012” by H. Bodén and G. Efraimsson, special issue of Journal of Sound and Vibration, Vol. 332 (25), September 2013.
[AX-8] S. Redonnet and G. Cunha, “Optimization of an Advanced Aeroacoustics Hybrid Approach, and Application to a Landing Gear Noise Problem”, in “Aeroacoustics research in Europe: The CEAS/ASC report on Highlights 2013” by Bennett et al., special issue of Journal of Sound and
Vibration, Vol. 340, January 2015.
[AX-9] S. Redonnet and J. Bulté, “Numerical Characterization of Noise Sources by a Simplified Landing Gear using Advanced Simulation and Analysis Techniques”, in “Aeroacoustics research in Europe: The CEAS/ASC report on Highlights 2015” by Jiricek et al., special issue of Journal of Sound
and Vibration, Vol. 381, 2016.
4.3. Communications in International Peer-Reviewed Conferences with Proceedings
[CC-1] S. Redonnet, E. Manoha and P. Sagaut, “Numerical Simulation of Propagation, for Small Perturbations Interacting with Flows and Solid Bodies”, AIAA paper 2001-2223, 7th AIAA/CEAS Aeroacoustics Conference, Maastricht, The Netherlands, May 2001.
[CC-2] E. Manoha, C. Delahay, S. Redonnet, P. Sagaut, I. Mary and P. Guillen,“The Numerical Prediction of the Airfoil Trailing Edge Noise”, 17th International Congress on Acoustics, Roma (Italy), September 2001.
[CC-3] E. Manoha, S. Redonnet, C. Delahay, S. Redonnet, P. Sagaut, I. Mary, S. Ben Khelil and P. Guillen,“ Numerical prediction of the unsteady flow and radiated noise from a 3D lifting airfoil”, RTO AVT Symposium on “Ageing Mechanisms and Control – Part I: Developments in Computational Aero- and Hydro-Acoustics”, Manchester (UK), October 2001.
[CC-4] E. Manoha, C. Herrero, P. Sagaut and S. Redonnet, “Numerical Prediction of Airfoil Aerodynamic Noise”, AIAA paper 2002-2573, 8th AIAA/CEAS Aeroacoustics Conference, Breckenridge, USA, June 2002.
[CC-5] E. Manoha, R. Guénanff, S. Redonnet and M. Terracol, “Acoustic Scattering from Complex Geometries”, AIAA paper 2004-2938, 10th AIAA/CEAS Aeroacoustics Conference, Manchester, UK, May 2004.
[CC-6] S. Redonnet and E. Manoha, “Numerical Simulation of the Downstream Fan Noise and Jet Noise of a Coaxial Jet with a Shielding Surface”, AIAA paper 2004-2991, 10th AIAA/CEAS Aeroacoustics Conference, Manchester, England, May 2004.
[CC-7] E Manoha, S. Redonnet, M. Terracol and R. Guénanff, “Numerical Simulation of Aerodynamic Noise”, 4th ECCOMAS Conference, Jyväskylä (Finland), July 2004.
[CC-8] C. Polacsek, S. Burguburu, S. Redonnet, M. Terracol, “Numerical Simulations of Fan Interaction Noise using a Hybrid Approach”, AIAA paper 2005-2814, 11th AIAA/CEAS Aeroacoustics Conference, Monterey, USA, 23-25 May, 2005.
[CC-9] S. Redonnet, E. Manoha and O. Kenning, “Numerical Simulation of the Downstream Fan Noise of 3D Coaxial Engines”, AIAA paper 2005-2816, 11th AIAA/CEAS Aeroacoustics Conference, Monterey, USA, 23-25 May, 2005.
[CC-10] S. Redonnet, E. Manoha and O. Kenning, “Application of the ONERA’s sAbrinA solver to the Numerical Investigation of the Engine Noise Reduction offered by New Aircraft Concepts”, Paper
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[CC-11] S. Redonnet, G. Desquesnes, E. Manoha and M. Terracol, “Numerical Study of Acoustic Installation Effects onto the Aft Fan Noise of a Coaxial Engine”, Paper 117, 9th WESPAC - Western Pacific Acoustics Conference, Seoul (Korea), June 2006. Invited contribution.
[CC-12] S. Redonnet, E. Manoha, “Towards the Numerical Simulation of Engine Installation Effects for Rear Fan Noise”, Paper 448, Internoise Congress, Honolulu, USA, 3-6 December 2006.
[CC-13] D. Mincu, S. Redonnet, G. Desquesnes and E. Manoha, “Numerical Simulations of Equivalent Acoustic Sources Generation and Propagation over a 2D High-Lift Wing in an Heterogeneous Mean Flow”, AIAA paper 2007-3514, 13th AIAA/CEAS Aeroacoustics Conference, Roma, Italy, May 2007.
[CC-14] G. Delattre, P. Sagaut, E. Manoha and S. Redonnet, “Time Domain Simulation of Sound Absorption on Curved Wall”, AIAA paper 2007-3493, 13th AIAA/CEAS Aeroacoustics Conference, Roma, Italy, May 2007.
[CC-15] S. Redonnet, C. Parzani, E. Manoha and D. Lizarazu, “Numerical Study of 3D Acoustic Installation Effects through a Hybrid Euler/BEM method”, AIAA paper 2007-3500, 13th AIAA/CEAS Aeroacoustics Conference, Roma, Italy, May 2007.
[CC-16] S. Redonnet, G. Desquesnes and E. Manoha, “Numerical Study of Acoustic Installation Effects through a Chimera CAA Method”, AIAA paper 2007-3501, 13th AIAA/CEAS Aeroacoustics Conference, Roma (Italy), May 2007.
[CC-17] S. Redonnet, D. Mincu and E Manoha, “A Source Term Formulation for the Non Linear Euler’s Equations in a Conservative and Perturbation Form”, Paper 117, 14th ICSV Congress, Cairns (Australia), July 2007.
[CC-18] S. Redonnet, G. Desquesnes and E. Manoha, “3D Numerical Simulations of Acoustic Installation Effects on Aft Fan Noise for Turbofan Engine”, Paper 6, 14th ICSV Congress, Cairns (Australia), July 2007.
[CC-19] D. Mincu, Y. Mary, S. Redonnet, L. Larchevêque and J.P. Dussauge, “Numerical Simulations of the Unsteady Flow and Radiated Noise over a Cylindrical Cavity”, AIAA paper 2008-2917, 14th AIAA/CEAS Aeroacoustics Conference, Vancouver, Canada, May 2008.
[CC-20] M. Omaïs, S. Redonnet, B. Caruelle and E. Manoha, “Jet Noise Prediction using RANS CFD Input”, AIAA paper 2008-2938, 14th AIAA/CEAS Aeroacoustics Conference, Vancouver, Canada, May 2008.
[CC-21] S. Redonnet, D. Mincu and E. Manoha, “Computational AeroAcoustics of Realistic Co-Axial Engines”, AIAA paper 2008-2826, 14th AIAA/CEAS Aeroacoustics Conference, Vancouver, Canada, May 2008.
[CC-22] S. Redonnet, D. Mincu and E. Manoha, “Computational AeroAcoustics of Realistic Co-Axial Engines”, Acoustics 2008 Conference, Paris, France, July 2008.
[CC-23] D. Mincu, Y. Mary, S. Redonnet, E. Manoha and L. Larchevêque, “Numerical simulations of the sound generation by flow over surface mounted cylindrical cavities including wind tunnel installation effects”, AIAA paper 2009-3314, 15th AIAA/CEAS Aeroacoustics Conference, Miami, USA, May 2009.
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[CC-24] S. Redonnet, D. Mincu, E. Manoha, B.Caruelle and A. Sengissen, “Computational AeroAcoustics of a Realistic Co-Axial Engine in Subsonic and Supersonic Take-Off Conditions”,
AIAA paper 2009-3240, 15th AIAA/CEAS Aeroacoustics Conference, Miami, USA, May 2009.
[CC-25] T. Le Garrec, E. Manoha and S. Redonnet, “Flow noise predictions using RANS/CAA computations”, AIAA paper 2010-3156, 16th AIAA/CEAS Aeroacoustics Conference, Stockholm, Sweden, June 2010.
[CC-26] D. Mincu, E. Manoha, C. Parzani, J. Chappuis, S. Redonnet, R. Davy and M. Escouflaire “Numerical and Experimental Characterization of Aft Fan Noise for Isolated and Installed configurations”, AIAA paper 2010-3918, 16th AIAA/CEAS Aeroacoustics Conference, Stockholm, Sweden, June 2010.
[CC-27] S. Redonnet, D. Mincu and G Delattre, “Computational AeroAcoustics of a Realistic Co-Axial Engine, possibly Equipped with Acoustic Liners”, AIAA paper 2010-3717, 16th AIAA/CEAS Aeroacoustics Conference, Stockholm, Sweden, June 2010.
[CC-28] S. Redonnet, “On the Numerical Prediction of Aerodynamic Noise via a Hybrid Approach - Part 1: CFD/CAA Surfacic Coupling Methodology, Revisited for the Prediction of Installed Airframe Noise Problems”, AIAA paper 2010-3709, 16th AIAA/CEAS Aeroacoustics Conference, Stockholm, Sweden, June 2010.
[CC-29] D. Mincu, E. Manoha G. Reboul, S. Redonnet and S. Pascal, “Numerical simulation of broadband aft fan noise radiation for turbofan with scarfed nozzle”, AIAA paper 2011-2941, 17th AIAA/CEAS Aeroacoustics Conference, Portland, USA, June 2011.
[CC-30] F. Vuillot, F. Houssen, E. Manoha, S. Redonnet, and J. Jacob, “Applications of the CEDRE unstructured flow solver to landing gear unsteady flow and noise predictions”, AIAA paper 2011-2944, 17th AIAA/CEAS Aeroacoustics Conference, Portland, USA, June 2011.
[CC-31] G. Cunha and S. Redonnet, “An Innovative Interpolation Technique for Aeroacoustic Hybrid Methods”, AIAA paper 2011-2483, 17th AIAA/CEAS Aeroacoustics Conference, Portland, Oregon, USA, June 2011.
[CC-32] S. Redonnet, D. P. Lockard, M. R. Khorrami and M. M. Choudhari, “CFD-CAA Coupled Calculations of a Tandem Cylinder Configuration to Assess Facility Installation Effects”, AIAA paper
2011-2841, 17th AIAA/CEAS Aeroacoustics Conference, Portland, USA, June 2011.
[CC-33] F. Vuillot, N. Lupoglazoff, D. Luquet, L. Sanders, E. Manoha and S. Redonnet, “Hybrid CAA Solutions for Nose Landing Gear Noise”, AIAA paper 2012-2283, 18th AIAA/CEAS Aeroacoustics Conference, Colorado Springs, USA, June 2012.
[CC-34] G. Cunha and S. Redonnet, “Towards a Robust and Accurate CFD-CAA Coupling Procedure for Hybrid Methods in Aeroacoustics - Part 1: On the Optimization of CFD/CAA Coupled Calculations”, AIAA paper 2012-2063, 18th AIAA/CEAS Aeroacoustics Conference, Colorado Springs, USA, June 2012.
[CC-35] S. Redonnet and G. Cunha, “Towards a Robust and Accurate CFD-CAA Coupling Procedure for Hybrid Methods in Aeroacoustics - Part 2: On the Application of the CFD-CAA Surface Weak Coupling Methodology to Realistic Aircraft Noise Problems”, AIAA paper 2012-2191, 18th AIAA/CEAS Aeroacoustics Conference, Colorado Springs, USA, June 2012.
[CC-36] S. Redonnet, “Computational Aeroacoustics of the Aft Fan Noise Emission by a Lined Realistic Exhaust”, Paper 1284, Internoise Congress, New York City, USA, August, 2012. Invited
