Jean Perraud

Jean Perraud
The French Aerospace Lab ONERA | ONERA · DMPE - Department Multi Physics and Energetics

Master of Science (ISVR) Engineering degree (UTC)

About

45
Publications
12,331
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661
Citations
Citations since 2017
5 Research Items
344 Citations
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Introduction
Jean Perraud currently works at the DMPE - Department of Multi Physics and Energetics , The French Aerospace Lab ONERA. Jean does research in Fluid Dynamics and laminar-turbulent transition. Involved in projects like AG51, internal ONERA projects, and European Research Project CleanSky2

Publications

Publications (45)
Conference Paper
Full-text available
Predicting the location of laminar-turbulent transition, and modelling the transition region inside a separation bubble are two related questions presently limiting the performance of flow simulations. Considering these questions requires both an understanding of the underlying physics and a number of improvements of the available numerical tools....
Conference Paper
Full-text available
Laminar-turbulent boundary layer transition has an important impact on wall heat exchange and friction, especially in case of high speed vehicles. Much work has been done to implement efficient transition prediction tools directly into RANS solvers, mostly in the transonic domain. Current work aims at reaching Mach 8 in case of 2D ideal gas flow wi...
Conference Paper
The laminar-turbulent transition is a key feature of hypersonic flows on reentry vehicles. For a smooth wall, its position can be estimated by a stability analysis of the boundary-layer, using the Local Stability Theory (LST) or the Parabolized Stability Equations (PSE). These techniques have been applied to the trajectory of Reentry-F flight exper...
Article
Full-text available
Delaying laminar-turbulent transition is considered a crucial issue with respect to the reduction of airplanes' environmental impact, allowing the reduction of skin friction drag and thus fuel consumption. As part of this theme, boundary-layer destabilizing effects of surface imperfections (assembly gaps, steps, rivets, waviness, and holes) have be...
Conference Paper
This paper presents an extension of the γ-Rθt~ transition model of Menter et al. (2006) that aims to take into account the effect of a specific type of surface roughness on the transition location. This was done by implementing the roughness transition onset correction of Stripf et al. (2009) inside the γ-Rθt~ model. Stripf et al. have developed a...
Article
Full-text available
With the objective of inserting laminar-turbulent transition prediction inside computational fluid dynamics codes (Navier-Stokes solvers and boundary-layer codes), a physically based transition criterion for laminar-turbulent longitudinal transition caused by the amplification of boundary-layer instabilities is developed and implemented into both t...
Article
Full-text available
In this paper, the effects of gaps on the boundary layer transition are investigated on an ONERA-D airfoil both experimentally and numerically. The experiment has been conducted in a subsonic wind tunnel for several gap geometries and aerodynamic conditions. Hot-wire anemometry was used to quantify the transition modification induced by the imperfe...
Conference Paper
This paper presents RANS computation results on the highly-loaded low-pressure turbine blade T106C using the Display Formula γ - R θ t ~ transition model. First, a setup methodology is described, addressing key points such as inlet values for the turbulence variables and stagnation point anomaly. This setup yields good results overall using the tra...
Conference Paper
Full-text available
Laminar-turbulent transition in CFD codes is considered very important with regard to flow topology (laminar flow is more prone to separation) and performance (laminar friction coefficient is smaller than the turbulent one) predictions. Fast and precise models are required to be inserted into RANS codes running tens of thousands iterations. The old...
Article
Full-text available
6th European Conference on Computational Fluid Dynamics (ECFD VI) July 20 - 25, 2014, Barcelona, Spain Overview of transition prediction tools in elsA software Long term involvement of ONERA in laminar-turbulent transition modelling, and into the development of the elsA software, with major contributions from D. Arnal, R. Houdeville et al. have l...
Article
Full-text available
Renewed interest in practical laminar flow control has motivated a number of European research activities in these last years. Laminar wings design now includes the question of laminar flow 'resistance' to small surface deformations and accidents in surface quality, for which prediction tools are needed. This paper presents several models developed...
Conference Paper
Full-text available
Within the European Project Telfona the Pathfinder Model was designed, analyzed numerically, constructed and tested with the aim of obtaining a laminar flow testing capability in the European Transonic Wind Tunnel (ETW). The model was designed for natural laminar flow (NLF) for transonic flow conditions with high Reynolds number. Results of pre-tes...
Conference Paper
Full-text available
A wind-tunnel experiment on laminar-turbulent transition has been performed in ETW at high Reynolds number and cryogenic conditions. The studied geometry is a swept-wing configuration. The transition location was determined by means of Temperature Sensitive Paint (TSP). The experimental observations were further analysed using different transition...
Conference Paper
Full-text available
The Pathfinder model was designed in the course of the TELFONA European Research Project as a calibration tool to evaluate the transonic, cryogenic ETW facility for laminar flow testing, and assess the possibility for studies of NLF or HLF wings in ETW. The Pathfinder wing is a simplified, low taper, swept wing with an optimized profile allowing al...
Conference Paper
Full-text available
With the goal of studying Natural Laminar Flow (NLF) wings for future ‘green’ transport aircraft, the aim of the European Research Project TELFONA is to develop and demonstrate the possibility of testing full aircraft models at large Reynolds numbers in the cryogenic Wind Tunnel ETW, with direct measurements of total drag. Two main steps were defin...
Article
Full-text available
Laminar-turbulent transition remains a critical issue in a number of cases, among which drag reduction, performance prediction of high lift systems, improved accuracy in general CFD, or reduction of computation cycles for development of optimization tools. Transition delay remains one of the most promising technologies for reducing air transport en...
Conference Paper
Full-text available
Laminar-turbulent transition is commonly recognized as an important factor in the design of re-entry vehicles. In the framework of the European project EXPERT, organized by the European Space Agency (ESA), CIRA and ONERA have worked together to design and implement on the EXPERT capsule an experiment on natural transition. The aim of the present wo...
Article
Full-text available
The evolution of maximum lift coefficient of a transport aircraft as a function of Reynolds number can be linked to modifications of the laminar-turbulent transition process. In the framework of European project EUROLIFT (I), a task was dedicated to the physical understanding and the numerical modeling of the transition process in high-lift configu...
Article
Laminar-turbulent transition appears in high-lift configurations through instabilities, attachment-line contamination, or separation. Its prediction may improve the estimation of maximum lift and allows the extrapolation from wind-tunnel measurements to flight conditions. This prediction is being inserted within Reynolds-averaged Navier–Stokes code...
Conference Paper
The evolution of maximum lift coefficient of a transport aircraft as a function of Reynolds number can be linked to modifications of the laminar-turbulent transition process. In the framework of European project EUROLIFT (I), a task was dedicated to the physical understanding and the numerical modeling of the transition process in high-lift configu...
Conference Paper
Full-text available
The evolution of maximum lift coefficient of a transport aircraft as a function of Reynolds number can be linked to modifications of the laminar-turbulent transition process. In the framework of European project EUROLIFT (I), a task was dedicated to the physical understanding and the numerical modeling of the transition process in high-lift configu...
Conference Paper
Full-text available
With the objective to integrate the transition prediction within RANS codes with a minimal user interaction, cooperative actions are under way in the frame of the European EUROLIFT 2 Project, especially involved with the improvement of the knowledge of the flow developed around the modeling of high lift configurations. Transition criteria and simpl...
Conference Paper
Full-text available
Laminar-turbulent transition appears in high lift configurations through instabilities, attachment line contamination or separation. Its prediction may improve the estimation of maximum lift, and allow the extrapolation from wind tunnel measurements to flight conditions. This prediction is being inserted within RANS codes, in order to become part o...
Article
Full-text available
This paper presents experimental and numerical studies on the effect of the Reynolds number on transition location for a simplified multi-element wing. The main phases of the test preparation and the main results of the data analysis carried out within the EUROLIFT EC funded programme are given in a first part. In the second part of the paper, rece...
Article
Full-text available
Shock wave/boundary-layer interactions in hypersonic flows may have major consequences on thermal loads, especially if the shock is strong enough to induce separation. The heat-flux density levels in the interaction region strongly depend on the nature, laminar or turbulent of the boundary-layer. Special attention should be paid to transitional int...
Article
Full-text available
The experimental and numerical transitional interactions in hypersonic flow are studied. The experiments were performed on a hollow cylinder-flare model in the ONERA R2Ch wind tunnel at a Mach number of 5 and for varying stagnation pressure. Wall pressure and heat-flux measurements, laser Doppler velocimetry, pitot boundary-layer surveys, surface f...
Conference Paper
Full-text available
Laminar-turbulent transition is commonly recognized as an important factor in the design of re-entry vehicles. In the framework of the European project EXPERT, organized by the European Space Agency (ESA), CIRA, ONERA and VKI are working together to design and implement on the EXPERT capsule an experiment on induced transition. The aim of the prese...
Article
Full-text available
Major results and findings of the numerical work package of the European high lift programme EUROLIFT are outlined. The main objective of these studies is to validate and test numerical methods for the prediction of high lift flows for transport aircraft configurations. The activities comprise the assessment of current CFD methods for 3D flows, eva...
Conference Paper
Full-text available
Maintaining laminar flow over aerodynamic surfaces reduces wall friction, hence increasing range or decreasing operating costs. Full laminar wings would result in a reduction of 10 to 15% of total drag. Sustained efforts in this domain have already brought optimized wing profiles and boundary layer control by wall suction through perforated walls....
Article
Full-text available
Performance of transport aircraft in high-lift conditions is directly related to the maximum lift. However, most of the high-lift tests are carried out at subscale conditions, and performance is then derived by extrapolation to flight Reynolds number. So-called adverse Reynolds number effects (sudden decrease of maximum lift with increasing Reynold...
Conference Paper
Full-text available
Shock wave/boundary layer interactions in hypersonic flows are a major problem with very important consequences as thermal loads are concerned. This article is devoted to the experimental and numerical study o f the shock wave transitional boundary layer interaction in hypersonic flow (M=5). The experiments were performed on a hollow cylinder flare...
Article
In the framework of the European Research Program EUROLIFT (European High Lift Program), the ONERA experimental contribution is a basic experiment to study the transition phenomenon on a swept model equipped with a slat and a flap in high lift configuration. In preparation for the tests, the 3D high lift configuration has been computed at ONERA wit...
Article
Full-text available
Shock wave/boundary layer interactions in hypersonic flows are a major problem with very important consequences as thermal loads are concerned. This article is devoted to the experimental and numerical study of the shock wave transitional boundary layer interaction in hypersonic flow (M=5). The experiments were performed on a hollow cylinder flare...
Conference Paper
Full-text available
Numerical and experimental investigations have been conducted in order to assess the tolerable heights of wall defaults (steps or gaps) in various types of laminar flows. After Navier Stokes computation of the mean flow, in presence of backward or forward facing steps, and gaps, linear stability computation was performed using local and non local t...
Article
Full-text available
This article deals with the research performed in the framework of the internal ONERA Hyperenthalpic Hypersonic Project. This project involved fifteen researchers specialised in different domains, which are the following: fundamental studies on shock-wave and shock/boundary layers interactions; study of the laminar/turbulent transition; real gas ef...
Conference Paper
Full-text available
Laminar-turbulent transition in hypersonic boundary layers remains an important issue with respect to thermal exchange and protection. Several aspects have been considered in the recent past at ONERA. First, local linear stability theory has been extended to non-perfect gases, to represent the effects of molecular dissociation and chemical reaction...
Article
Full-text available
Flight tests using a Fokker F100 aircraft equipped with a natural laminar flow glove demonstrated that natural laminar now is feasible for transport aircraft with up to 130 passengers. Furthermore, the flight tests generated a wealth of experimental data. These data have been evaluated with all known variations of tbe e<SUP>N</SUP> method. The aim...
Conference Paper
Full-text available
Laminar-turbulent transition in hypersonic boundary layer usually corresponds to a steep rise in wall heat ux, from a low laminar value to a much higher turbulent one. Transition prediction is thus important with regard to atmospheric reentry vehicle design, particularly when determining the distribution and mass of thermal protection. In the case...
Article
Experiments focusing on a better understanding of the phenomena of boundary layer transition under nonzero pressure gradient and at high Reynolds number are presented. Wall pressure fluctuation measurements on a rotation model, previously used in the anechoic wind tunnel CEPRA 19 and in the aerohydrodynamic tunnel of CEAT Toulouse, allows compariso...
Article
Full-text available
Experimental studies of the laminar-turbulent boundary layer transition were conducted with the same axisymmetric test body in air and in water. First results established a clear causal relation between turbulent intermittency and a very wide band (20 to 30 kHz), low level acoustic emission. Further experiments yielded observations of a natural tra...
Article
Two models are developed to characterize the sources and propagation of hydrodynamic noise in towing tanks. Empirical data on hydroacoustic noise was gathered with hydrophones in two tanks. The data comprised three axes of the acoustic field, harmonic variations of the amplitude and phase, and frequencies from 40-350 Hz. A modal approach to describ...

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Projects (5)
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