Log in

Relevant bibliographies by topics / Turbulent shear layers / Dissertations / Theses

To see the other types of publications on this topic, follow the link: Turbulent shear layers.

Dissertations / Theses on the topic 'Turbulent shear layers'

Author: Grafiati

Published: 9 November 2024

Last updated: 31 July 2025

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 50 dissertations / theses for your research on the topic 'Turbulent shear layers.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.

1

Abu-Hijleh, Bassam Abdel-Kareem A.-R. "Structure of supersonic turbulent reattaching shear layers /." The Ohio State University, 1990. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487676261012304.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Luo, Jian Yang. "Calculation of turbulent shear layers over highly curved surfaces." Thesis, Imperial College London, 1989. http://hdl.handle.net/10044/1/11500.

Full text

APA, Harvard, Vancouver, ISO, and other styles

3

Sreedhar, Madhu K. "Large eddy simulation of turbulent vortices and mixing layers." Diss., This resource online, 1994. http://scholar.lib.vt.edu/theses/available/etd-06062008-163324/.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Wang, Kan. "Computational investigation of aero-optical distortions by turbulent boundary layers and separated shear layers." Thesis, University of Notre Dame, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=3578995.

Full text

Abstract:

<p> Aero-optical distortions are detrimental to airborne optical systems. To study distortion mechanisms, compressible large-eddy simulations are performed for a Mach 0.5 turbulent boundary layer and a separated shear layer over a cylindrical turret with and without passive control in the upstream boundary layer. Optical analysis is carried out using ray tracing based on the computed density field and Gladstone-Dale relation.</p><p> In the flat-plate boundary layer, the effects of aperture size, Reynolds number, small-scale turbulence, different flow regions and beam elevation angle are exam

APA, Harvard, Vancouver, ISO, and other styles

5

Hipp, Hans Christoph 1959. "Numerical investigation of mode interaction in free shear layers." Thesis, The University of Arizona, 1988. http://hdl.handle.net/10150/276871.

Full text

Abstract:

Numerical simulations of incompressible, two-dimensional, monochromatically and bichromatically forced laminar free shear layers are performed on the basis of a vorticity-velocity formulation of the complete Navier-Stokes equations employing central finite differences. Spatially periodic shear layers developing in time (temporal model) are compared with shear layers developing in the stream-wise direction (spatial model). The regimes of linear growth and saturation of the fundamental are quantitatively scrutinized, the saturation of the subharmonic and vortex merging are investigated, and the

APA, Harvard, Vancouver, ISO, and other styles

6

Schmidt, Martin Arnold. "Microsensors for the measurement of shear forces in turbulent boundary layers." Thesis, Massachusetts Institute of Technology, 1988. http://hdl.handle.net/1721.1/14781.

Full text

APA, Harvard, Vancouver, ISO, and other styles

7

Ciochetto, David S. "Analysis of Three Dimensional Turbulent Shear Flow Experiments with Respect to Algebraic Modeling Parameters." Thesis, Virginia Tech, 1997. http://hdl.handle.net/10919/36808.

Full text

Abstract:

The extension of the theory for two dimensional turbulent boundary layers into three dimensional flows has met with limited success. The failure of the extended models is attributed to the anisotropy of the turbulence. This is seen by the turbulent shear stress angle lagging the flow gradient angle and by the behavior of the Reynolds shear stresses lagging that of the mean flow. Transport equations for the turbulent shear stresses were proposed to be included in a modeling effort capable of accounting for the lags seen in the flow. This study is aimed at developing algebraic relationships betw

APA, Harvard, Vancouver, ISO, and other styles

8

McGinnis, David C. "Aero Optic Characterization of Highly Turbulent Free Shear Layers Over a Backward Facing Step." University of Cincinnati / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1367928372.

Full text

APA, Harvard, Vancouver, ISO, and other styles

9

Martin, Martin Laura. "Numerical study of sound scattering by isolated elliptic vortices and turbulent jet shear layers." Electronic Thesis or Diss., Ecully, Ecole centrale de Lyon, 2024. http://www.theses.fr/2024ECDL0025.

Full text

Abstract:

Cette étude est consacrée à la diffusion d'ondes acoustiques par des tourbillons isolés et couches de cisaillement de jet turbulentes. Lorsque les ondes acoustiques traversent un volume de turbulence, les fluctuations de la turbulence modifient la direction de propagation des ondes. En outre, si la turbulence évolue dans le temps, le contenu spectral du son change également, ce qui entraîne un élargissement spectral. Afin de mieux comprendre ces phénomènes, une série d'analyses numériques a été réalisée. Pour ce faire, un code fourni par Siemens a été utilisé, dans lequel les Equations d'Euler

APA, Harvard, Vancouver, ISO, and other styles

10

Miller, Ronald J. "A Study of Passive Scalar Mixing in Turbulent Boundary Layers using Multipoint Correlators." Thesis, Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/7574.

Full text

Abstract:

This study analyzes a turbulent passive scalar field using two-point and three-point correlations of the fluctuating scalar field. Multipoint correlation functions are investigated because they retain scaling property information and simultaneously probe the concentration field for the spatial structure of the scalar filaments. Thus, multipoint correlation functions provide unique information about the spatial properties of the concentration filaments. The concentration field is created by the iso-kinetic release of a high Schmidt number dye into a fully developed turbulent boundary layer o

APA, Harvard, Vancouver, ISO, and other styles

11

Freeman, Jeffrey L. "On the Growth Rate of Turbulent Mixing Layers: A New Parametric Model." DigitalCommons@CalPoly, 2014. https://digitalcommons.calpoly.edu/theses/1160.

Full text

Abstract:

A new parametric model for the growth rate of turbulent mixing layers is proposed. A database of experimental and numerical mixing layer studies was extracted from the literature to support this effort. The domain of the model was limited to planar, spatial, nonreacting, free shear layers that were not affected by artificial mixing enhancement techniques. The model is split into two parts which were each tuned to optimally fit the database; equations for an incompressible growth rate were derived from the error function velocity profile, and a function for a compressibility factor was generali

APA, Harvard, Vancouver, ISO, and other styles

12

Guskey, Christopher R. "NEAR WALL SHEAR STRESS MODIFICATION USING AN ACTIVE PIEZOELECTRIC NANOWIRE SURFACE." UKnowledge, 2013. http://uknowledge.uky.edu/me_etds/27.

Full text

Abstract:

An experimental study was conducted to explore the possible application of dynamically actuated nanowires to effectively disturb the wall layer in fully developed, turbulent channel flow. Actuated nanowires have the potential to be used for the mixing and filtering of chemicals, enhancing convective heat transfer and reducing drag. The first experimental evidence is presented suggesting it is possible to manipulate and subsequently control turbulent flow structures with active nanowires. An array of rigid, ultra-long (40 μm) TiO2 nanowires was fabricated and installed in the bounding wall of t

APA, Harvard, Vancouver, ISO, and other styles

13

COHEN, JACOB. "INSTABILITIES IN TURBULENT FREE SHEAR FLOWS." Diss., The University of Arizona, 1986. http://hdl.handle.net/10150/188143.

Full text

Abstract:

The evolution of the large scale structures and the mean field were investigated in axisymmetric and plane mixing layers. Some aspects of the linear instability of an axisymmetric jet have been demonstrated. The axisymmetric geometry admits two additional length scales with relation to the two-dimensional shear layer: the radius of the jet column and the azimuthal wavelength. The importance of these two length scales in governing the instability of an axisymmetric jet was explored. The special case of a thin axisymmetric shear layer was analyzed and the results stressing the evolution of diffe

APA, Harvard, Vancouver, ISO, and other styles

14

Naaseri, Masud. "Studies of complex three-dimensional turbulent flows." Thesis, Imperial College London, 1990. http://hdl.handle.net/10044/1/7379.

Full text

APA, Harvard, Vancouver, ISO, and other styles

15

Slessor, Michael David Dimotakis Paul E. "Aspects of turbulent-shear-layer dynamics and mixing /." Diss., Pasadena, Calif. : California Institute of Technology, 1998. http://resolver.caltech.edu/CaltechETD:etd-03292005-085835.

Full text

APA, Harvard, Vancouver, ISO, and other styles

16

Soteriou, Marios C. "Numerical study of turbulent combustion in a shear layer." Thesis, Massachusetts Institute of Technology, 1993. http://hdl.handle.net/1721.1/12333.

Full text

APA, Harvard, Vancouver, ISO, and other styles

17

Johnstone, Henry Webb 1956. "CONFINED JET-INDUCED MIXING AT A DENSITY INTERFACE (TURBULENT, SHEAR FLOW)." Thesis, The University of Arizona, 1987. http://hdl.handle.net/10150/292003.

Full text

APA, Harvard, Vancouver, ISO, and other styles

18

Ailinger, Kevin Gerard. "Measurements of surface shear stresses under a three-dimensional turbulent boundary layer using oil-film laser interferometry." Thesis, This resource online, 1990. http://scholar.lib.vt.edu/theses/available/etd-11012008-063040/.

Full text

APA, Harvard, Vancouver, ISO, and other styles

19

Oljaca, Miodrag. "Optical phase distortions in a plane shear layer." Diss., Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/18178.

Full text

APA, Harvard, Vancouver, ISO, and other styles

20

Baum, Bryan Alan. "The extension of rapid distortion theory to stratified shear flows." Diss., Georgia Institute of Technology, 1989. http://hdl.handle.net/1853/25971.

Full text

APA, Harvard, Vancouver, ISO, and other styles

21

Lindgren, Björn. "Flow facility design and experimental studies of wall-bounded turbulent shear-flows." Doctoral thesis, KTH, Mechanics, 2002. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3454.

Full text

Abstract:

<p>The presen present thesis spans a range of topics within thearea of turbulent flows, ranging from design of flow facilitiesto evaluation aluation of scaling laws and turbulence modelingdeling aspects through use of experimental data. A newwind-tunnel has been designed, constructed and evaluated at theDept. of Mechanics, KTH. Special attention was directed to thedesign of turning vanes that not only turn the flow but alsoallow for a large expansion without separation in the corners.The investigation of the flow quality confirmed that theconcept of expanding corners is feasible and may besucc

APA, Harvard, Vancouver, ISO, and other styles

22

Šálený, Vratislav. "Numerická simulace hluku generovaného nestabilitami ve smykové vrstvě." Doctoral thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2018. http://www.nusl.cz/ntk/nusl-383530.

Full text

Abstract:

Predicting and inhibiting aerodynamically generated noise for fast moving vehicles such as cars, aircraft and trains is increasingly important. The tonal noise generated by the shear-layer instability of air flowing around the cavity opening is especially one of the most significant and most intense sources of aerodynamically generated noise. Computational aeroacoustics (CAA) based on the CFD simulations of compressible Navier-Stokes equations offers the most general approach to predicting those aerodynamically induced sounds. Aeroacoustics is practically always associated with turbulent flow

APA, Harvard, Vancouver, ISO, and other styles

23

Hellum, Aren. "Intermittency and the viscous superlayer in a single stream shear layer." Diss., Connect to online resource - MSU authorized users, 2006.

Find full text

APA, Harvard, Vancouver, ISO, and other styles

24

Kandil, Sherif M. "A computational study of mixing in a liquid jet impinging on an immiscible liquid layer." Morgantown, W. Va. : [West Virginia University Libraries], 2001. http://etd.wvu.edu/templates/showETD.cfm?recnum=1941.

Full text

Abstract:

Thesis (M.S.)--West Virginia University, 2001.<br>Title from document title page. Document formatted into pages; contains xii, 113 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 95-98).

APA, Harvard, Vancouver, ISO, and other styles

25

Semeraro, Onofrio. "Feedback control and modal structures in transitional shear flows." Licentiate thesis, KTH, Stabilitet, Transition, Kontroll, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-29754.

Full text

Abstract:

Two types of shear flows are investigated in this thesis; numerical simulations are performed for the analysis and control of the perturbation arising in a boundary layer over a flat plate, whereas PIV measurements are analysed for the investigation of a confined turbulent jet. Modal structures of the flows are identified: the aim is to understand the flow phenomena and to identify reduced-order models for the feedback control design. The attenuation of three-dimensional wavepackets of streaks and Tollmien-Schlichting (TS) waves in the boundary layer is obtained using feedback control based on

APA, Harvard, Vancouver, ISO, and other styles

26

Semeraro, Onofrio. "Active Control and Modal Structures in Transitional Shear Flows." Doctoral thesis, KTH, Stabilitet, Transition, Kontroll, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-117916.

Full text

Abstract:

Flow control of transitional shear flows is investigated by means of numerical simulations. The attenuation of three-dimensional wavepackets of Tollmien-Schlichting (TS) and streaks in the boundary layer is obtained using active control in combination with localised sensors and actuators distributed near the rigid wall. Due to the dimensions of the discretized Navier-Stokes operator, reduced-order models are identified, preserving the dynamics between the inputs and the outputs of the system. Balanced realizations of the system are computed using balanced truncation and system identification.

APA, Harvard, Vancouver, ISO, and other styles

27

Ecker, Tobias. "Turbulence Statistics and Eddy Convection in Heated Supersonic Jets." Diss., Virginia Tech, 2015. http://hdl.handle.net/10919/51687.

Full text

Abstract:

Supersonic hot jet noise causes significant hearing impairment to the military workforce and results in substantial cost for medical care and treatment. Detailed insight into the turbulence structure of high-speed jets is central to understanding and controlling jet noise. For this purpose a new instrument based on the Doppler global velocimetry technique has been developed. This instrument is capable of measuring three-component velocity vectors over ex-tended periods of time at mean data-rates of 100 kHz. As a demonstration of the applicability of the time-resolved Doppler global velocimetry

APA, Harvard, Vancouver, ISO, and other styles

28

Mayo, Jr David Earl. "The Turbulence Structure of Heated Supersonic Jets with Offset Total Temperature Non-Uniformities." Diss., Virginia Tech, 2019. http://hdl.handle.net/10919/93532.

Full text

Abstract:

Noise induced hearing loss is a large concern for the Department of Defense. Personnel on aircraft carriers are exposed to dangerous noise levels of noise from tactical aircraft, causing hearing damage which results in significant costs for medical care and treatment. Additionally, NASA and the FAA have begun to investigate the viability of reintroducing supersonic commercial transport in the United States and one of the largest problems to address is reducing the noise impact of these aircraft on communities. The overarching goal of jet noise research is to optimize noise reduction technique

APA, Harvard, Vancouver, ISO, and other styles

29

Stella, Francesco. "Caractérisation d’un décollement turbulent sur une rampe : entraînement et lois d’échelle." Thesis, Orléans, 2017. http://www.theses.fr/2017ORLE2043/document.

Full text

Abstract:

Les décollements turbulents massifs sont des phénomènes communs qui peuvent causer des pertes et de nuisances aérodynamiques importantes dans les écoulements industriels, par exemple à l’arrière d’une aile d’avion. Ce travail contribue à leur compréhension par l’analyse phénoménologique d’un décollement turbulent, représentatif d’un grand nombre d’écoulements réels. Le premier objectif est d’identifier les lois d’échelle des décollements turbulents, notamment en rapport avec les caractéristiques de l’écoulement à l’amont de la rampe. Un deuxième objectif est l’analyse, à grande et à petite éch

APA, Harvard, Vancouver, ISO, and other styles

30

Gunasekaran, Sidaard. "Relationship Between the Free Shear Layer, the Wingtip Vortex and Aerodynamic Efficiency." University of Dayton / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1470231642.

Full text

APA, Harvard, Vancouver, ISO, and other styles

31

Maji, S., P. R. Hanmaiahgari, R. Balachandar, Jaan H. Pu, A. M. Ricardo, and R. M. L. Ferreira. "A review on hydrodynamics of free surface flows in emergent vegetated channels." MDPI, 2020. http://hdl.handle.net/10454/17820.

Full text

Abstract:

Yes<br>This review paper addresses the structure of the mean flow and key turbulence quantities in free-surface flows with emergent vegetation. Emergent vegetation in open channel flow affects turbulence, flow patterns, flow resistance, sediment transport, and morphological changes. The last 15 years have witnessed significant advances in field, laboratory, and numerical investigations of turbulent flows within reaches of different types of emergent vegetation, such as rigid stems, flexible stems, with foliage or without foliage, and combinations of these. The influence of stem diameter, volum

APA, Harvard, Vancouver, ISO, and other styles

32

Akins, David J. "Control of the Turbulent Shear Layer Downstream of a Backward Facing Step using Nanosecond Pulse Driven Surface Plasma Discharges: Effects of Pulse Energy." Thesis, The University of Arizona, 2016. http://hdl.handle.net/10150/613578.

Full text

Abstract:

The influence of pulse energy on nanosecond pulse driven dielectric barrier discharge (ns-DBD) plasma actuation applied to the turbulent shear layer downstream of a backward facing step (BFS) is examined experimentally. The ns-DBD control mechanism, which is believed to be primarily thermal in contrast to most other flow control actuators, has been demonstrated in various high speed shear flows yet questions on fundamental physics and scaling remain unanswered. In this work, ns-DBD pulse amplitude is varied between 0.13mJ/cm-0.88mJ/cm per pulse in order to understand its effects on the excitat

APA, Harvard, Vancouver, ISO, and other styles

33

Cerino, Bastien. "Large-scale flow structures in shallow mixing layers over uniform and spanwise-heterogeneous bed surfaces." Electronic Thesis or Diss., Lyon 1, 2024. http://www.theses.fr/2024LYO10269.

Full text

Abstract:

Ce travail de doctorat examine l’effet de la rugosité du lit sur les couches de mélange peu profondes (SML) et l’évolution des structures cohérentes qui les peuplent, telles que les Structures Cohérentes de Kelvin-Helmholtz (KHCSs), les Courants Secondaires (SCs), les tourbillons de grande ou très grande taille (en anglais, Large ou Very-Large Scale Motions, LSMs et VLSMs respectivement). Deux scénarios de rugosité du lit sont considérés : un lit uniformément rugueux et une transition latérale d’un lit rugueux à un lit lisse. Le lit rugueux est constitué d’un gazon dense artificiel d’une haute

APA, Harvard, Vancouver, ISO, and other styles

34

Ihala, Gallangage Gedara Maheshwara Arunakantha Prasad. "Hydrodynamics of open channel flow with partially occupied continuous double layered vegetation." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2024. https://ro.ecu.edu.au/theses/2930.

Full text

Abstract:

This doctoral thesis investigates the hydrodynamics of open channel flows interacting with double-layered vegetation, focusing on two configurations—uniform (A1) and mixed (A2)—that mimic river riparian growth. The study utilizes Laser Doppler Velocimetry (LDV) and Particle Image Velocimetry (PIV) to quantify critical flow characteristics, including streamwise and transverse velocities, Reynolds shear stress, turbulence, and vortex dynamics under conditions where vegetation occupies single and both banks. The dynamic effects of channel transitions from wide to narrow are studied utilizing aspe

APA, Harvard, Vancouver, ISO, and other styles

35

Mathey, Fabrice. "Ecoulements cisaillés réactifs : étude par modélisation sous-maille du mélange et simulation numérique des grandes échelles." Université Joseph Fourier (Grenoble), 1997. http://www.theses.fr/1997GRE10215.

Full text

Abstract:

Le formalisme de la simulation des grandes echelles (les) pour l'etude des ecoulements turbulents est presente. Des tests, en configuration de turbulence homogene isotrope et de couche de melange temporelle, mettent en evidence le comportement des differents modeles de viscosite turbulente vis-a-vis de la dissipation generee par les correcteurs de flux du schema ppm. Une solution est proposee permettant d'eviter une dissipation numerique trop importante pour les ecoulements en turbulence developpee et d'eviter le developpement d'instabilites numeriques dues aux conditions initiales. Les modele

APA, Harvard, Vancouver, ISO, and other styles

36

Bagheri, Shervin. "Analysis and control of transitional shear flows using global modes." Doctoral thesis, Stockholm : Department of Mechanics, Royal Institute of Technology, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-11894.

Full text

APA, Harvard, Vancouver, ISO, and other styles

37

Huret, Thomas. "Génération en soufflerie d'écoulements cisaillés représentatifs des écoulements environnementaux de couches limites atmosphériques par des dispositifs passifs." Electronic Thesis or Diss., Centrale Lille Institut, 2024. http://www.theses.fr/2024CLIL0011.

Full text

Abstract:

Dans le domaine de l'ingénierie du vent, les dispositifs les plus couramment utilisés à la fois en milieux académiques et industriels pour générer des écoulements de couches limites atmosphériques en soufflerie consistent à associer des rugosités de paroi à un alignement de «spires» (flèches) en amont. Si des modèles permettent effectivement de concevoir a priori ce type de dispositifs passifs pour généré un champs moyen donné, le contrôle du profil d’intensité turbulente nécessite un processus d’ajustements par essai-erreur long et coûteux à réitérer chaque nouvelle configuration souhaitée.En

APA, Harvard, Vancouver, ISO, and other styles

38

Malla, Bhupatindra. "Study of High-speed Subsonic Jets using Proper Orthogonal Decomposition." University of Cincinnati / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1352397174.

Full text

APA, Harvard, Vancouver, ISO, and other styles

39

Millican, Anthony J. "Bio-Inspired Trailing Edge Noise Control: Acoustic and Flow Measurements." Thesis, Virginia Tech, 2017. http://hdl.handle.net/10919/78376.

Full text

Abstract:

Trailing edge noise control is an important problem associated mainly with wind turbines. As turbulence in the air flows over a wind turbine blade, it impacts the trailing edge and scatters, producing noise. Traditional methods of noise control involve modifying the physical trailing edge, or the scattering efficiency. Recently, inspired by the downy covering of owl feathers, researchers developed treatments that can be applied to the trailing edge to significantly reduce trailing edge noise. It was hypothesized that the noise reduction was due to manipulating the incoming turbulence, rather t

APA, Harvard, Vancouver, ISO, and other styles

40

Rehab, Hichem. "Structure de l'écoulement et mélange dans le champ proche des jets coaxiaux." Université Joseph Fourier (Grenoble), 1997. http://www.theses.fr/1997GRE10074.

Full text

Abstract:

Le present travail est une etude experimentale de l'ecoulement dans le champ proche des jets coaxiaux a fort rapport des vitesses initiales entre le courant annulaire et central. Les objectifs de l'etude sont de clarifier les mecanismes physiques qui gouvernent la dynamique de l'ecoulement et les regimes d'ecoulement. Deux regimes d'ecoulement sont identifies selon les valeurs du rapport des vitesses initiales comparee a une certaine valeur critique. Le premier regime est caracterise par un cone potentiel central dont la longueur est inversement proportionnelle au rapport des vitesses. Un mode

APA, Harvard, Vancouver, ISO, and other styles

41

Si-Ameur, Mohamed. "Simulations numériques de mélanges turbulents dans les écoulements cisaillés supersoniques." Université Joseph Fourier (Grenoble ; 1971-2015), 1994. http://www.theses.fr/1994GRE10214.

Full text

Abstract:

L'etude du melange turbulent dans des ecoulements cisailles supersoniques, couche de melange confinee entre parois et jet faiblement sous detendu, est abordee a l'aide de simulations numeriques tridimensionnelles instationnaires. Un code aux volumes finis est utilise dans cette optique. La technique de simulation des grandes echelles a ete utilisee, les effets sous-maille etant pris en compte par les proprietes de l'algorithme numerique ppm qui filtre les concentrations de vorticite a petite echelle. Cette technique nous a permis de considerer certains caracteres des ecoulements reels: prise e

APA, Harvard, Vancouver, ISO, and other styles

42

Khelif, Djamal. "Contribution a l'etude de la couche de melange plane : conditions de formation et evolution de la structure tourbillonnaire." Poitiers, 1987. http://www.theses.fr/1987POIT2256.

Full text

Abstract:

Etude experimentale de la structure tourbillonnaire dans une zone de melange confinee formee par la rencontre de deux ecoulements plans paralleles debouchant a vitesses differentes dans un canal rectangulaire. Visualisation des deux ecoulements incidents permettant de determiner l'influence de ces derniers sur les grosses structures coherentes. Traitement numerique de sequences d'images

APA, Harvard, Vancouver, ISO, and other styles

43

Bennaceur, Iannis. "Etude numérique de la diffusion d'une onde acoustique par une couche de cisaillement turbulente à l'aide d'une simulation aux grandes échelles." Thesis, Aix-Marseille, 2017. http://www.theses.fr/2017AIXM0187/document.

Full text

Abstract:

Lors des mesures acoustiques dans les souffleries à veine ouverte, les ondes acoustiques émises par une maquette ou une source située dans la veine se propagent dans la couche de cisaillement turbulente qui se forme aux abords du jet avant d’être reçues par les microphones localisés en dehors. L’onde acoustique interagit avec le champ de vitesse turbulent de la couche de mélange ce qui a pour effet de modifier son contenu spectral, de redistribuer spatialement son énergie et de moduler sa phase et son amplitude, on parle alors de diffusion acoustique. Cette thèse a consisté à l’étude de la dif

APA, Harvard, Vancouver, ISO, and other styles

44

Tarbouriech, Laurent. "Développement d'une méthode de vélocimétrie par images de particules pour les grandes dimensions : application à l'étude expérimentale d'un sillage turbulent soumis à la rotation." Grenoble INPG, 1996. http://www.theses.fr/1996INPG0212.

Full text

Abstract:

Les objectifs de cette these etaient, dans un premier temps, de developper une methode de mesure globale et non intrusive adaptee aux grandes dimensions de la plaque tournante coriolis du legi (13 m de diametre). Dans un second temps, il fallait appliquer cette methode au sillage plan turbulent soumis a la rotation solide. La methode developpee permet de realiser des mesures de champs de vitesse a deux composantes par images de particules (piv). Grace a la tres haute definition offerte par l'acquisition sur film des images, nos mesures s'etendent sur plusieurs metres carres avec une erreur the

APA, Harvard, Vancouver, ISO, and other styles

45

Kaya, Serpil. "Reynolds-averaged Navier-stokes Computations Of Jet Flows Emanating From Turbofan Exhausts." Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/2/12610078/index.pdf.

Full text

Abstract:

This thesis presents the results of steady, Reynolds-averaged Navier-Stokes (RANS) computations for jet flow emanating from a generic turbofan engine exhaust. All computations were performed with commercial solver FLUENT v6.2.16. Different turbulence models were evaluated. In addition to turbulence modeling issues, a parametric study was considered. Different modeling approaches for turbulent jet flows were explained in brief, with specific attention given to the Reynolds-averaged Navier-Stokes (RANS) method used for the calculations. First, a 2D ejector problem was solved to find out the mos

APA, Harvard, Vancouver, ISO, and other styles

46

Scheller, Johannes. "Electroactive morphing for the aerodynamic performance improvement of next generation airvehicles." Phd thesis, Toulouse, INPT, 2015. http://oatao.univ-toulouse.fr/14479/1/scheller_partie_1_sur_2_2.pdf.

Full text

Abstract:

The need to improve the aerodynamic performance of air vehicles is the origin of intense research on the real-time optimization of the airfoil shape. This real-time optimization can only be achieved by morphing the airfoil using adequate materials and actuators. The object of this thesis is to study smart-material actuators for aerodynamic performance optimization on different time scales (low-frequent and high-frequent actuation). First, the effects of the distinct actuation types, low-frequency large-displacement shape-memory alloy (SMA) and high-frequency low-displacement piezoelectric, on

APA, Harvard, Vancouver, ISO, and other styles

47

Brun, Christophe. "Étude expérimentale et numérique de l'interaction forte entre sillages d'obstacles cylindriques." Université Joseph Fourier (Grenoble ; 1971-2015), 1998. http://www.theses.fr/1998GRE10049.

Full text

Abstract:

Cette etude s'interesse aux phenomenes caracteristiques de la formation et de l'interaction des sillages turbulents en aval d'obstacles cylindriques en configuration complexe. Pour le bas regime sous-critique de nombre de reynolds nous effectuons une investigation de la zone de proche sillage de facon a la fois experimentale via des mesures de vitesse par anemometrie laser doppler et numerique via des simulations 2d avec raffinement du maillage en paroi. Dans un premier temps nous etudions le cas de l'interaction forte entre deux cylindres en parallele dont l'ecartement bord a bord est inferie

APA, Harvard, Vancouver, ISO, and other styles

48

Novozámský, Adam. "Střih větru jako nebezpečný jev v letectví." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2014. http://www.nusl.cz/ntk/nusl-231313.

Full text

Abstract:

This thesis is about wind shear and its influence on aviation. There is wide theoretical description of wind shear and it’s implemented into aviation practice. There are also methods of observation, forecasting and reporting, for both pilots and meteorologist described. In this thesis, pilots can find useful recommendations for dealing with wind shear during the flight. Every reader can also read about famous aviation accidents and look at models of weather that caused those accidents. At the end of thesis there are analyses of a rawiosonde measurements related to wind shear reports. This whol

APA, Harvard, Vancouver, ISO, and other styles

49

Lang, Daniel Bernard. "Laser Doppler Velocity and Vorticity Measurements in Turbulent Shear Layers." Thesis, 1985. https://thesis.library.caltech.edu/3291/10/Lang.1985.thesis_opt.pdf.

Full text

Abstract:

<p>A Laser Doppler Velocimeter (LDV) system was developed to measure the instantaneous spanwise vorticity, -w<sub>z</sub>, in a turbulent shear layer. It was necessary to design and fabricate the LDV optics and processing electronics, as no commercially available LDV systems met the specifications of measuring the velocity at four closely spaced points to the requisite accuracy. Measurements were also made of the instantaneous u, v, u', v', and -u'v'. The instantaneous vorticity was processed to obtain an estimate of its probability density function, from which the mean and rms values were

APA, Harvard, Vancouver, ISO, and other styles

50

Hall, Jeffery Lawrence. "An experimental investigation of structure, mixing and combustion in compressible turbulent shear layers." Thesis, 1991. https://thesis.library.caltech.edu/3727/1/Hall_jl_1991.pdf.

Full text

Abstract:

Two-dimensional, compressible, turbulent shear layers are studied in a new wind tunnel facility. Both reacting and non-reacting flows are investigated, with one free stream velocity supersonic and the other subsonic. The combustion experiments are based on the use of low concentrations of hydrogen, nitric oxide and fluorine gases. Side-view Schlieren photographs of these reacting and non-reacting flows appear devoid of the two-dimensional, large-scale structures seen in incompressible flows. Comparison with all-subsonic flows produced in the same facility suggests that this lack of two-dimensi

APA, Harvard, Vancouver, ISO, and other styles

We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!