Bibliographies thématiques / Wave turbulence interaction

Littérature scientifique sur le sujet « Wave turbulence interaction »

Auteur : Grafiati

Publié le 7 juillet 2024

Mis à jour le 7 juillet 2024

Créez une référence correcte selon les styles APA, MLA, Chicago, Harvard et plusieurs autres

Choisissez une source :

Consultez les listes thématiques d’articles de revues, de livres, de thèses, de rapports de conférences et d’autres sources académiques sur le sujet « Wave turbulence interaction ».

À côté de chaque source dans la liste de références il y a un bouton « Ajouter à la bibliographie ». Cliquez sur ce bouton, et nous générerons automatiquement la référence bibliographique pour la source choisie selon votre style de citation préféré : APA, MLA, Harvard, Vancouver, Chicago, etc.

Vous pouvez aussi télécharger le texte intégral de la publication scolaire au format pdf et consulter son résumé en ligne lorsque ces informations sont inclues dans les métadonnées.

Articles de revues sur le sujet "Wave turbulence interaction"

XU, CHANG-YUE, LI-WEI CHEN et XI-YUN LU. « NUMERICAL SIMULATION OF SHOCK WAVE AND TURBULENCE INTERACTION OVER A CIRCULAR CYLINDER ». Modern Physics Letters B 23, n^o 03 (30 janvier 2009) : 233–36. http://dx.doi.org/10.1142/s0217984909018084.

Texte intégral

Résumé :

The interaction of shock wave and turbulence for transonic flow over a circular cylinder is investigated using detached-eddy simulation (DES). Several typical cases are calculated for free-stream Mach number M∞ from 0.85 to 0.95, and the physical mechanisms relevant to the shock wave and turbulence interaction are discussed. Results show that there exist two flow states. One is unsteady flow state with moving shock waves interacting with turbulent flow for M∞ < 0.9 approximately, and the other is quasi-steady flow with stationary shocks standing over the wake of the cylinder for M∞ > 0.9, suppressing the vortex shedding from the cylinder. Moreover, local supersonic zones are identified in the wake of the cylinder and generated by two processes, i.e., reverse flow and shock wave distortion induced the supersonic zone. Turbulent shear layer instabilities are revealed and associated with moving shock wave and traveling pressure wave.

Styles APA, Harvard, Vancouver, ISO, etc.

Thais, L., et J. Magnaudet. « Turbulent structure beneath surface gravity waves sheared by the wind ». Journal of Fluid Mechanics 328 (10 décembre 1996) : 313–44. http://dx.doi.org/10.1017/s0022112096008749.

Texte intégral

Résumé :

New experiments have been carried out in a large laboratory channel to explore the structure of turbulent motion in the water layer beneath surface gravity waves. These experiments involve pure wind waves as well as wind-ruffled mechanically generated waves. A submersible two-component LDV system has been used to obtain the three components of the instantaneous velocity field along the vertical direction at a single fetch of 26 m. The displacement of the free surface has been determined simultaneously at the same downstream location by means of wave gauges. For both types of waves, suitable separation techniques have been used to split the total fluctuating motion into an orbital contribution (i.e. a motion induced by the displacement of the surface) and a turbulent contribution. Based on these experimental results, the present paper focuses on the structure of the water turbulence. The most prominent feature revealed by the two sets of experiments is the enhancement of both the turbulent kinetic energy and its dissipation rate with respect to values found near solid walls. Spectral analysis provides clear indications that wave–turbulence interactions greatly affect energy transfers over a significant frequency range by imposing a constant timescale related to the wave-induced strain. For mechanical waves we discuss several turbulent statistics and their modulation with respect to the wave phase, showing that the turbulence we observed was deeply affected at both large and small scales by the wave motion. An analysis of the phase variability of the bursting suggests that there is a direct interaction between the waves and the underlying turbulence, mainly at the wave crests. Turbulence budgets show that production essentially takes place in the wavy region of the flow, i.e. above the wave troughs. These results are finally used to address the nature of the basic mechanisms governing wave–turbulence interactions.

Styles APA, Harvard, Vancouver, ISO, etc.

Tsai, Wu-ting, Shi-ming Chen et Guan-hung Lu. « Numerical Evidence of Turbulence Generated by Nonbreaking Surface Waves ». Journal of Physical Oceanography 45, n^o 1 (janvier 2015) : 174–80. http://dx.doi.org/10.1175/jpo-d-14-0121.1.

Texte intégral

Résumé :

AbstractNumerical simulation of monochromatic surface waves propagating over a turbulent field is conducted to reveal the mechanism of turbulence production by nonbreaking waves. The numerical model solves the primitive equations subject to the fully nonlinear boundary conditions on the exact water surface. The result predicts growth rates of turbulent kinetic energy consistent with previous measurements and modeling. It also validates the observed horizontal anisotropy of the near-surface turbulence that the spanwise turbulent intensity exceeds the streamwise component. Such a flow structure is found to be attributed to the formation of streamwise vortices near the water surface, which also induces elongated surface streaks. The averaged spacing between the streaks and the depth of the vortical cells approximates that of Langmuir turbulence. The strength of the vortices arising from the wave–turbulence interaction, however, is one order of magnitude less than that of Langmuir cells, which arises from the interaction between the surface waves and the turbulent shear flow. In contrast to Langmuir turbulence, production from the Stokes shear does not dominate the energetics budget in wave-induced turbulence. The dominant production is the advection of turbulence by the velocity straining of waves.

Styles APA, Harvard, Vancouver, ISO, etc.

George, S. G., et A. R. L. Tatnall. « Measurement of turbulence in the oceanic mixed layer using Synthetic Aperture Radar (SAR) ». Ocean Science Discussions 9, n^o 5 (13 septembre 2012) : 2851–83. http://dx.doi.org/10.5194/osd-9-2851-2012.

Texte intégral

Résumé :

Abstract. Turbulence in the surface layer of the ocean contributes to the transfer of heat, gas and momentum across the air-sea boundary. As such, study of turbulence in the ocean surface layer is becoming increasingly important for understanding its effects on climate change. Direct Numerical Simulation (DNS) techniques were implemented to examine the interaction of small-scale wake turbulence in the upper ocean layer with incident electromagnetic radar waves. Hydrodynamic-electromagnetic wave interaction models were invoked to demonstrate the ability of Synthetic Aperture Radar (SAR) to observe and characterise surface turbulent wake flows. A range of simulated radar images are presented for a turbulent surface current field behind a moving surface vessel, and compared with the surface flow fields to investigate the impact of turbulent currents on simulated radar backscatter. This has yielded insights into the feasibility of resolving small-scale turbulence with remote-sensing radar and highlights the potential for extracting details of the flow structure and characteristics of turbulence using SAR.

Styles APA, Harvard, Vancouver, ISO, etc.

Klyuev, Dmitriy S., Andrey N. Volobuev, Sergei V. Krasnov, Kaira A. Adyshirin-Zade, Tatyana A. Antipova et Natalia N. Aleksandrova. « Some features of a radio signal interaction with a turbulent atmosphere ». Physics of Wave Processes and Radio Systems 25, n^o 4 (31 décembre 2022) : 122–28. http://dx.doi.org/10.18469/1810-3189.2022.25.4.122-128.

Texte intégral

Résumé :

On the basis of the solution of Maxwells equations system for electromagnetic radiation in a turbulent atmosphere the differential effective section of scattering of this radiation on turbulence is found. Dependence of scattering section on wave length and an angle of scattering is investigated. It is shown that interaction of electromagnetic radiation and turbulence of an atmosphere is interaction of the determined electromagnetic wave process with stochastic turbulent wave process. It is marked, that the wave vector of scattering electromagnetic radiation is proportional to a wave vector of turbulence.

Styles APA, Harvard, Vancouver, ISO, etc.

Lee, Sangsan, Sanjiva K. Lele et Parviz Moin. « Direct numerical simulation of isotropic turbulence interacting with a weak shock wave ». Journal of Fluid Mechanics 251 (juin 1993) : 533–62. http://dx.doi.org/10.1017/s0022112093003519.

Texte intégral

Résumé :

Interaction of isotropic quasi-incompressible turbulence with a weak shock wave was studied by direct numerical simulations. The effects of the fluctuation Mach number Mt of the upstream turbulence and the shock strength M21 — 1 on the turbulence statistics were investigated. The ranges investigated were 0.0567 ≤ Mt ≤ 0.110 and 1.05 ≤ M1 ≤ 1.20. A linear analysis of the interaction of isotropic turbulence with a normal shock wave was adopted for comparisons with the simulations.Both numerical simulations and the linear analysis of the interaction show that turbulence is enhanced during the interaction with a shock wave. Turbulent kinetic energy and transverse vorticity components are amplified, and turbulent lengthscales are decreased. The predictions of the linear analysis compare favourably with simulation results for flows with M2t < a(M21 — 1) with a ≈ 0.1, which suggests that the amplification mechanism is primarily linear. Simulations also showed a rapid evolution of turbulent kinetic energy just downstream of the shock, a behaviour not reproduced by the linear analysis. Investigation of the budget of the turbulent kinetic energy transport equation shows that this behaviour can be attributed to the pressure transport term.Shock waves were found to be distorted by the upstream turbulence, but still had a well-defined shock front for M2t < a(M21— 1) with a ≈ 0.1). In this regime, the statistics of shock front distortions compare favourably with the linear analysis predictions. For flows with M2t > a(M21— 1 with a ≈ 0.1, shock waves no longer had well-defined fronts: shock wave thickness and strength varied widely along the transverse directions. Multiple compression peaks were found along the mean streamlines at locations where the local shock thickness had increased significantly.

Styles APA, Harvard, Vancouver, ISO, etc.

Beya, Jose, William Peirson et Michael Banner. « ATTENUATION OF GRAVITY WAVES BY TURBULENCE ». Coastal Engineering Proceedings 1, n^o 32 (2 février 2011) : 3. http://dx.doi.org/10.9753/icce.v32.waves.3.

Texte intégral

Résumé :

We report new laboratory measurements of the interaction between mechanically-generated gravity waves and turbulence generated by simulated rain. Wave attenuation coefficients and vertical profiles of turbulent velocity fluctuations were measured. Observations are in broad agreement with Teixeira and Belcher (2002) despite substantial differences between assumed and measured turbulence profiles. Wave attenuation due to surface turbulence appears to be stronger than theoretical estimates. These finding could have significant implications for the next generation of spectral wave models and the understanding of wave dissipation processes.

Styles APA, Harvard, Vancouver, ISO, etc.

KEATING, SHANE R., et P. H. DIAMOND. « Turbulent resistivity in wavy two-dimensional magnetohydrodynamic turbulence ». Journal of Fluid Mechanics 595 (8 janvier 2008) : 173–202. http://dx.doi.org/10.1017/s002211200700941x.

Texte intégral

Résumé :

The theory of turbulent resistivity in ‘wavy’ magnetohydrodynamic turbulence in two dimensions is presented. The goal is to explore the theory of quenching of turbulent resistivity in a regime for which the mean field theory can be rigorously constructed at large magnetic Reynolds number Rm. This is achieved by extending the simple two-dimensional problem to include body forces, such as buoyancy or the Coriolis force, which convert large-scale eddies into weakly interacting dispersive waves. The turbulence-driven spatial flux of magnetic potential is calculated to fourth order in wave slope – the same order to which one usually works in wave kinetics. However, spatial transport, rather than spectral transfer, is the object here. Remarkably, adding an additional restoring force to the already tightly constrained system of high Rm magnetohydrodynamic turbulence in two dimensions can actually increase the turbulent resistivity, by admitting a spatial flux of magnetic potential which is not quenched at large Rm, although it is restricted by the conditions of applicability of weak turbulence theory. The absence of Rm-dependent quenching in this wave-interaction-driven flux is a consequence of the presence of irreversibility due to resonant nonlinear three-wave interactions, which are independent of collisional resistivity. The broader implications of this result for the theory of mean field electrodynamics are discussed.

Styles APA, Harvard, Vancouver, ISO, etc.

Quadros, Russell, Krishnendu Sinha et Johan Larsson. « Turbulent energy flux generated by shock/homogeneous-turbulence interaction ». Journal of Fluid Mechanics 796 (28 avril 2016) : 113–57. http://dx.doi.org/10.1017/jfm.2016.236.

Texte intégral

Résumé :

High-speed turbulent flows with shock waves are characterized by high localized surface heat transfer rates. Computational predictions are often inaccurate due to the limitations in modelling of the unclosed turbulent energy flux in the highly non-equilibrium regions of shock interaction. In this paper, we investigate the turbulent energy flux generated when homogeneous isotropic turbulence passes through a nominally normal shock wave. We use linear interaction analysis where the incoming turbulence is idealized as being composed of a collection of two-dimensional planar vorticity waves, and the shock wave is taken to be a discontinuity. The nature of the postshock turbulent energy flux is predicted to be strongly dependent on the angle of incidence of the incoming waves. The energy flux correlation is also decomposed into its vortical, entropy and acoustic contributions to understand its rapid non-monotonic variation behind the shock. Three-dimensional statistics, calculated by integrating two-dimensional results over a prescribed upstream energy spectrum, are compared with available data from direct numerical simulations. A detailed budget of the governing equation is also considered in order to gain insight into the underlying physics.

Styles APA, Harvard, Vancouver, ISO, etc.

LAKEHAL, DJAMEL, et PETAR LIOVIC. « Turbulence structure and interaction with steep breaking waves ». Journal of Fluid Mechanics 674 (4 avril 2011) : 522–77. http://dx.doi.org/10.1017/jfm.2011.3.

Texte intégral

Résumé :

Large-eddy and interface simulation using an interface tracking-based multi-fluid flow solver is conducted to investigate the breaking of steep water waves on a beach of constant bed slope. The present investigation focuses mainly on the ‘weak plunger’ breaking wave type and provides a detailed analysis of the two-way interaction between the mean fluid flow and the sub-modal motions, encompassing wave dynamics and turbulence. The flow is analysed from two points of views: mean to sub-modal exchange, and wave to turbulence interaction within the sub-modal range. Wave growth and propagation are due to energy transfer from the mean flow to the waves, and transport of mean momentum by these waves. The vigorous downwelling–upwelling patterns developing at the head and tail of each breaker are shown to generate both negative- and positive-signed energy exchange contributions in the thin sublayer underneath the water surface. The details of these exchange mechanisms are thoroughly discussed in this paper, together with the interplay between three-dimensional small-scale breaking associated with turbulence and the dominant two-dimensional wave motion. A conditional zonal analysis is proposed for the first time to understand the transient mechanisms of turbulent kinetic energy production, decay, diffusion and transport and their dependence and/or impact on surface wrinkling over the entire breaking process. The simulations provide a thorough picture of air–liquid coherent structures that develop over the breaking process, and link them to the transient mechanisms responsible for their local incidence.

Styles APA, Harvard, Vancouver, ISO, etc.

Plus de sources

Thèses sur le sujet "Wave turbulence interaction"

Teixeira, Miguel Angelo Cortez. « Interaction of turbulence with a free surface ». Thesis, University of Reading, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.340045.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Wheadon, Andrew John. « Wave-turbulence interaction in shallow water numerical models : asymptotic limits, and subgrid interactions ». Thesis, University of Exeter, 2018. http://hdl.handle.net/10871/34333.

Texte intégral

Résumé :

The ability to directly simulate all atmospheric motion is currently well beyond the limits of the computers available to us. As such techniques must be developed that accurately model important processes in an affordable manner. Large-scale balanced motion is well understood, but as affordable resolution increases, models are able to resolve scales where large-scale turbulence and small-scale waves are important. This requires a new set of techniques that respect the interactions between these different kinds of motion. In this thesis we look at two ways of assessing the accuracy of models capable of representing the scales at which these interactions occur. The first approach uses asymptotic limit solutions to derive a set of terms whose scale is known. These terms can then be evaluated as the model approaches a relevant asymptotic regime, and a `good' model should reproduce the expected rate of scaling. We apply this method of asymptotic limit solutions to an Eulerian and a Lagrangian shallow water model. The former is based upon ENDGame, the model currently in use at the Met Office, and the latter is based upon a candidate model from GungHo which is seeking a replacement for ENDGame. In addition, the Eulerian model is evaluated with both small and large timesteps and the results confirm the ability of the semi-implicit scheme to retain accuracy at large timesteps. Errors in the higher-order diagnostics used in this section highlight the need to make these analytic diagnostics consistent with the discretisations of the model in question. The second method involves looking at the exchanges of energy in a spectral shallow water model in order to inform the design of subgrid models. By running a high-resolution simulation and truncating the energy at a certain wavenumber, comparing the result to a run without truncation shows the contribution of the scales below the truncation limit. We extend this by separating the total energy into separate components that may be truncated and evaluated individually in order to give a more complete picture of energy exchanges at the subgrid scale.

Styles APA, Harvard, Vancouver, ISO, etc.

Dong, P. « The computation of wave-induced circulations with wave current interaction and refined turbulence modelling ». Thesis, Imperial College London, 1988. http://hdl.handle.net/10044/1/47036.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Jennings, Ross. « Empirical modelling of turbulence and wave-current interaction in tidal streams ». Thesis, University of Hull, 2017. http://hydra.hull.ac.uk/resources/hull:16600.

Texte intégral

Résumé :

The successful development of the tidal stream power industry fundamentally relies on a thorough, quantitative understanding of the available resource. Numerical simulations and laboratory flume experiments have demonstrated that increased turbulence and wave-induced motion can have detrimental effects on the fatigue and performance of prototype tidal stream turbines (TSTs). Knowledge of the relationships between mean current velocity, turbulence and surface waves is limited and presents a significant research gap. This research makes a significant contribution to the field by developing empirical models from in situ data collected within the Humber Estuary. These models estimate the turbulence strength and intensity at a point and through depth given a mean current velocity. An 18-day deployment of bed-mounted directional wave recorders (DWR) at Foul Holme Spit simultaneously recorded two-dimensional flow velocities and surface wave parameters. Static, vessel-mounted, acoustic Doppler current profiler (ADCP) surveys recorded turbulence through depth near St. Andrews Dock. The analyses revealed distinct relationships between the mean current velocity, turbulence strength and turbulence intensity at a point which are comparable to recently published results. The inter-tidal relationship between streamwise mean current velocity and turbulence strength is modelled at a point using power regression where α is 0.13 and β is 0.72 with an R2 value of 0.8721. The inter-tidal relationship between streamwise mean current velocity and turbulence intensity is modelled at a point using power regression where γ is 14.315 and δ is -0.2316 with an R2 value of 0.5482. A newly defined empirical relationship between depth-averaged mean current velocity and turbulence intensity is modelled using power regression where ε is 17.75 and ζ is -0.94 with an R2 value of 0.7912. The models derived at a point are tested on the data collected through depth and exhibited strong predictive capability within the order of 0.1 ms-1. The exponential approximation of wave-induced velocity, proposed by Soulsby (2006), was tested and shown to be inappropriate for estimating wave-induced velocities at this scale. A comparative spectral analysis between DWR sample bursts determined that spikes in the turbulence spectra can be attributed to surface wave parameters, thus validating the conceptual model proposed by Soulsby and Humphrey (1990).

Styles APA, Harvard, Vancouver, ISO, etc.

Wenger, Christian W. « Analysis of Two-point Turbulence Measurements for Aeroacoustics ». Thesis, Virginia Tech, 1998. http://hdl.handle.net/10919/30837.

Texte intégral

Résumé :

Simultaneous two-point three-component four-sensor hot-wire velocity measurements taken in three flows of aeroacoustic interest are here analyzed. The analyses provide information on the turbulence structure of the flows as it would be encountered by hypothetical noise producing blades passing through the flows. Two-point measurements taken in the first flow, a lifting wake from a rectangular NACA 0012 half wing, are used to calculate space-time correlation functions and 'pointwise' wave number frequency spectra. Two upwash spectra, calculated for locations in the region of the wake that is roughly homogenous in the spanwise direction, are direct estimates of the full wave number frequency spectra at their locations. As such, they are used to perform aeroacoustic calculations, and the results are compared to results achieved using the von KÃ¡rmÃ¡n isotropic spectrum. Amiet's approximation, where the wave number frequency spectra can be represented by the correlation length scales is found to hold reasonably well for the measured spectra.

The two-point measurements in the second flow, a vortex/blade-tip interaction, are analyzed to provide information useful to researchers of blade-wake interaction noise produced by helicopter rotors. Space-time correlation functions and wave number frequency spectra are calculated for five cuts through the region of interaction. The correlation functions provide information concerning the turbulence length scales found in the interaction region. The spectra are compared to the von KÃ¡rmÃ¡n isotropic spectrum and found to be greatly different. However, the spectra do bear some resemblance to spectra calculated in the spanwise homogenous region of the lifting wake.

The two-point measurements taken in the third flow, the wake from a fan cascade, are analyzed to provide information of use to modelers of broadband noise produced through rotor wake/stator interactions. In particular, space-time correlation functions are calculated for a grid of two-point measurements, which allows the estimation of the turbulence structure as seen by a passing stator blade. Space-time correlation functions and wave number frequency spectra are calculated for various stator configurations. The implications of engine operating speed and stator configuration for broadband noise production are discussed.

[Vita removed March 2, 2012. GMc]
Master of Science

Styles APA, Harvard, Vancouver, ISO, etc.

Mohamed, Ahmed. « Nonlinear inertial waves focusing in rotating flows ». Electronic Thesis or Diss., Ecully, Ecole centrale de Lyon, 2023. http://www.theses.fr/2023ECDL0058.

Texte intégral

Résumé :

Nous étudions la propagation des ondes inertielles générées par l’oscillation d’un tore axisymétrique dans un fluide en rotation. Ces ondes inertielles se propagent à partir du tore oscillant avec un angle de propagation θf, déterminé par la relation de dispersion. Elles convergent vers une région focale où des interactions non linéaires peuvent induire une turbulence. Notre étude utilise des simulations numériques directes pour modéliser cet écoulement, en tenant compte des régimes linéaires et non linéaires, et en utilisant deux configurations de forçage du tore. Le premier modèle simplifie le tore en tant que force volumique locale en utilisant une fonction delta de Dirac (anneau de Dirac) le long de la direction d’oscillation du tore dans les équations de conservation de la quantité de mouvement. Le deuxième modèle, plus réaliste, met en œuvre un tore en 3D en utilisant la méthode de pénalisation. Nos résultats révèlent l’émergence d’un vortex central résultant des interactions non linéaires des ondes inertielles propagées. Dans le cas de l’anneau de Dirac et du régime linéaire, nos résultats montrent une relation entre l’énergie cinétique verticale et l’angle de propagation au point focal, avec une énergie maximale se produisant à θf = 35o. De même, dans le scénario de forçage en 3D du tore, aussi bien dans les simulations linéaires que non linéaires, indiquent un angle optimal de θf = 30o, conduisant à une vitesse verticale maximale et à une dissipation maximale, signifiant un transfert efficace d’énergie de la source oscillante vers la région focale. Dans le régime non linéaire, nous présentons la distribution spectrale détaillée de l’énergie cinétique dans la zone focale et effectuons une analyse spatio-temporelle du champ de vitesse. Cette analyse identifie les résonances triadiques des ondes inertielles, qui génèrent une zone turbulente et un mode à grande échelle similaire à l’écoulement moyen géostrophique
We investigate the propagation of inertial waves generated by the oscillation of an axisymmetric torus in a rotating fluid. These inertial waves propagate from the oscillating torus with a propagation angle θf, determined by the dispersion relation. They focus to a focal region where nonlinear interactions may induce turbulence. Our study employs direct numerical simulations to model this flow, considering both linear and nonlinear regimes, and using two torus forcing configurations. The first model simplifies the torus as a local volume force using a Dirac delta function (Dirac ring) along the torus’s oscillation direction in the momentum conservation equations. The second, more realistic model implements a 3D torus using the penalization method. Our findings reveal the emergence of a central vortex as a result of the nonlinear interactions of the propagated inertial waves. In the case of the Dirac ring and the linear regime, our results demonstrate a relationship between vertical kinetic energy and propagation angle at thefocal point, with maximum energy occurring at θf = 35o. Similarly, in the 3D torus forcing scenario, both linear and nonlinear simulations indicate an optimal angle of θf = 30o, leading to maximum vertical velocity and dissipation, signifying efficient energy transfer from the oscillating source to the focal region. In the nonlinear regime, we show the detailed spectral distribution of kinetic energy within the focal zone and conduct spatio-temporal analysis of the velocity field. This analysis identifies triadic resonances of the inertial waves, which drive the generation of a turbulent patch and a large-scale mode similar to the geostrophic mean flow

Styles APA, Harvard, Vancouver, ISO, etc.

Gallagher, Stephen J. « Zonal flow generation through four wave interaction in reduced models of fusion plasma turbulence ». Thesis, University of Warwick, 2013. http://wrap.warwick.ac.uk/59703/.

Texte intégral

Résumé :

In tokamaks, turbulence is a key contributor to cross field transport. However, it is also responsible for the spontaneous generation of large scale structures such as zonal ows. These are of relevance to fusion plasmas as they can create transport barriers which aid plasma confinement. The interaction between drift waves and zonal ows can be investigated using reduced models such as the Hasegawa- Mima and Hasegawa-Wakatani equations. A four-wave truncated model is developed for the Extended-Hasegawa-Mima (EHM) equation. This produces a set of four ordinary differential equations (ODEs) that are used to investigate the modulational instability (MI), a mechanism by which drift waves can produce a zonal ow. These equations are linearised to produce a dispersion relation for the MI which is used to produce a set of maps of the linear growth rate of the MI. These show how additional modes become unstable as the gyroradius is increased. The truncated model and dispersion relation are then compared to measurements taken from simulations of the full EHM partial differential equation (PDE) which has been seeded with an appropriate initial condition. Good agreement is found when the pump wave has no component in the direction of the density gradient. A similar truncated model is derived for the Extended-Hasegawa-Wakatani (EHW) equations. As the EHW system has separate equations for density and potential this leads to a set of eight ODEs. The linearisation technique used for the EHM system cannot be applied here. Instead, approximations based on the built in EHW instability are made to calculate a linear growth rate for the zonal ow using the ODEs describing it. These analytical predictions are then compared to a full PDE simulation of the system, which is initialised using random noise. It is found that for particular sets of waves the ODEs provide a good prediction of the linear growth rate. A driving term is added to the EHM equation to reproduce the effect of the built in instability of the EHW equations. This causes a drift wave spectrum to grow when full EHW PDE simulations are seeded with random noise. The four-wave ODE model is updated to include this driving. The ODE model again produces good predictions for the growth rate of the zonal flow.

Styles APA, Harvard, Vancouver, ISO, etc.

Hornung, Grégoire. « Etude de la turbulence plasma par réflectrométrie à balayage ultra-rapide dans le tokamak Tore Supra ». Thesis, Aix-Marseille, 2013. http://www.theses.fr/2013AIXM4741/document.

Texte intégral

Résumé :

La turbulence plasma engendre un transport anormal de la chaleur et des particules qui dégrade l’efficacité d’un réacteur de fusion. La mesure de la turbulence plasma dans un tokamak est donc essentielle à la compréhension et au contrôle de ce phénomène. Parmi les instruments de mesure à disposition, le réflectomètre à balayage installé sur le tokamak Tore Supra a accès à la densité du plasma et ses fluctuations depuis le bord jusqu’au centre des décharges, avec une excellente résolution spatiale (mm) et temporelle (µs), de l’ordre des échelles de la turbulence. Cette thèse est dédiée à la caractérisation de la turbulence plasma dans Tore Supra à partir de mesures de réflectométrie à balayage ultrarapide. Des analyses de corrélations ont permis d’évaluer les échelles spatiales et temporelles de la turbulence ainsi que sa vitesse radiale. Dans la première partie, la caractérisation des propriétés de la turbulence à partir des profils de densité reconstruits est discutée, notamment au travers d’une comparaison avec les données des sondes de Langmuir. Ensuite une étude paramétrique est présentée mettant en relief l’effet de la collisionalité sur la turbulence, dont une interprétation est proposée en termes de stabilisation d’une turbulence électronique due aux électrons piégés. Finalement, on illustre comment le chauffage additionnel produit une modification locale de la turbulence dans le plasma proche des parois, se traduisant par une augmentation de la vitesse des structures et une diminution de leur temps de corrélation. L’effet supposé des potentiels rectifiés générés par l’antenne est étudié à l’aide de simulations
The performance of a fusion reactor is closely related to the turbulence present in the plasma. The latter is responsible for anomalous transport of heat and particles that degrades the confinement. The measure and characterization of turbulence in tokamak plasma is therefore essential to the understanding and control of this phenomenon. Among the available diagnostics, the sweeping reflectometer installed on Tore Supra allows to access the plasma density fluctuations from the edge to the centre of the plasma discharge with a fine spatial (mm) and temporal resolution (µs ) , that is of the order of the characteristic turbulence scales.This thesis consisted in the characterization of plasma turbulence in Tore Supra by ultrafast sweeping reflectometry measurements. Correlation analyses are used to quantify the spatial and temporal scales of turbulence as well as their radial velocity. In the first part, the characterization of turbulence properties from the reconstructed plasma density profiles is discussed, in particular through a comparative study with Langmuir probe data. Then, a parametric study is presented, highlighting the effect of collisionality on turbulence, an interpretation of which is proposed in terms of the stabilization of trapped electron turbulence in the confined plasma. Finally, it is shown how additional heating at ion cyclotron frequency produces a significant though local modification of the turbulence in the plasma near the walls, resulting in a strong increase of the structure velocity and a decrease of the correlation time. The supposed effect of rectified potentials generated by the antenna is investigated via numerical simulations

Styles APA, Harvard, Vancouver, ISO, etc.

Asproulias, Ioannis. « RANS modelling for compressible turbulent flows involving shock wave boundary layer interactions ». Thesis, University of Manchester, 2014. https://www.research.manchester.ac.uk/portal/en/theses/rans-modelling-for-compressible-turbulent-flows-involving-shock-wave-boundary-layer-interactions(e2293c9d-de93-4e97-b8b8-967ec0b682d8).html.

Texte intégral

Résumé :

The main objective of the thesis is to provide a detailed assessment of the performance of four types of Low Reynolds Number (LRN) Eddy Viscosity Models (EVM), widely used for industrial purposes, on flows featuring SWBLI, using experimental and direct numerical simulation data. Within this framework the two-equation linear k-ε of Launder and Sharma (1974) (LS), the two-equation linear k-ω SST, the four-equation linear φ-f of Laurence et al. (2004) (PHIF) and the non-linear k-ε scheme of Craft et al. (1996b,1999) (CLSa,b) have been selected for testing. As initial test cases supersonic 2D compression ramps and impinging shocks of different angles and Reynolds numbers of the incoming boundary layer have been selected. Additional test cases are then considered, including normal shock/isotropic turbulence interaction and an axisymmetric transonic bump, in order to examine the predictions of the selected models on a range of Mach numbers and shock structures. For the purposes of this study the PHIF and CLSa,b models have been implemented in the open source CFD package OpenFOAM. Some results from validation studies of these models are presented, and some explorations are reported of certain modelled source terms in the ε-equation of the PHIF and CLSb models in compressible flows. Finally, before considering the main applications of the study, an examination is made of the performance of different solvers and numerical methods available in OpenFOAM for handling compressible flows with shocks. The performance of the above models, is analysed with comparisons of wall-quantities (skin-friction and wall-pressure), velocity profiles and profiles of turbulent quantities (turbulent kinetic energy and Reynolds stresses) in locations throughout the SWBLI zones. All the selected models demonstrate a broadly consistent performance over the considered flow configurations, with the CLSb scheme generally giving some improvements in predictions over the other models. The role of Reynolds stress anisotropy in giving a better representation of the evolution of the boundary layer in these flows is discussed through the performance of the CLSb model. It is concluded that some of the main deficiencies of the selected models is the overestimation of the dissipation rate levels in the non-equilibrium regions of the flow and the underestimation of the amplification of Reynolds stress anisotropy, especially within the recirculation bubble of the flows. Additionally, the analysis of the performance of the considered EVM's in a normal shock/isotropic turbulence interaction illustrates some drawbacks of the EVM formulation similar to the ones observed in normally-strained incompressible flows. Finally, a hybrid Detached Eddy Simulation (DES) approach is incorporated for the prediction of the transonic buffet around a wing.

Styles APA, Harvard, Vancouver, ISO, etc.

Stamatiou, Evangelos. « Experimental investigation of the wave-turbulence interaction at low reynolds numbers in a horizontal open-channel flow ». Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape11/PQDD_0007/MQ40914.pdf.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Plus de sources

Livres sur le sujet "Wave turbulence interaction"

Milewski, Paul A., Leslie M. Smith, Fabian Waleffe et Esteban G. Tabak, dir. Advances in Wave Interaction and Turbulence. Providence, Rhode Island : American Mathematical Society, 2001. http://dx.doi.org/10.1090/conm/283.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Lee, Sangsan. Interaction of isotropic turbulence with a shock wave. Stanford, Calif : Thermo sciences Division, Dept. of Mechanical Engineering, Stanford University, 1992.

Trouver le texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Ribner, Herbert S. Spectrum of noise from shock-turbulence interaction. [S.l.] : [s.n.], 1986.

Trouver le texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

United States. National Aeronautics and Space Administration., dir. A simple theory of capillary-gravity wave turbulence. [Washington, DC : National Aeronautics and Space Administration, 1995.

Trouver le texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Rubinstein, Robert. The dissipation range in rotating turbulence. Hampton, VA : Institute for Computer Applications in Science and Engineering, NASA Langley Research Center, 1999.

Trouver le texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Kim, S. W. Numerical computation of shock wave-turbulent boundary layer interaction in transonic flow over an axisymmetric curved hill. Cleveland, Ohio : Lewis Research Center, 1989.

Trouver le texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

United States. National Aeronautics and Space Administration. et Lewis Research Center. Institute for Computational Mechanics in Propulsion., dir. Numerical investigation of separated transonic turbulent flows with a multiple-time-scale turbulence model. [Washington, D.C : National Aeronautics and Space Administration, 1990.

Trouver le texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

1931-, Toba Y., Mitsuyasu Hisashi 1929-, IOC/SCOR Committee on Climatic Changes and the Ocean., WMO/ICSU Joint Scientific Committee. et Symposium on Wave Breaking, Turbulent Mixing and Radio Probing of the Ocean Surface (1984 : Tohoku University), dir. The Ocean surface : Wave breaking, turbulent mixing, and radio probing. Dordrecht [Netherlands] : Reidel, 1985.

Trouver le texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

AMS-IMS-SIAM Joint Summer Research Conference on Dispersive Wave Turbulence (2000 Mount Holyoke College). Advances in wave interaction and turbulence : Proceedings of an AMS-IMS-SIAM Joint Summer Research Conference on Dispersive Wave Turbulence, Mount Holyoke College, South Hadley, MA, June 11-15, 2000. Sous la direction de Milewski Paul A. 1966-. Providence, R.I : American Mathematical Society, 2001.

Trouver le texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Center, Langley Research, dir. Laminar and turbulent flow computations of type IV shock-shock interference aerothermal loads using unstructured grids. Hampton, Va : National Aeronautics and Space Administration, Langley Research Center, 1994.

Trouver le texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Plus de sources

Chapitres de livres sur le sujet "Wave turbulence interaction"

Tanaka, Mitsuhiro. « Wave Turbulence : Interaction of Innumerable Waves ». Dans Physics of Nonlinear Waves, 161–79. Cham : Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-031-02611-9_8.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Debieve, J. F., et J. P. Lacharme. « A Shock-Wave/Free Turbulence Interaction ». Dans Turbulent Shear-Layer/Shock-Wave Interactions, 393–403. Berlin, Heidelberg : Springer Berlin Heidelberg, 1986. http://dx.doi.org/10.1007/978-3-642-82770-9_31.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Shen, Lian. « Numerical Study of Turbulence–Wave Interaction ». Dans Notes on Numerical Fluid Mechanics and Multidisciplinary Design, 37–49. Berlin, Heidelberg : Springer Berlin Heidelberg, 2010. http://dx.doi.org/10.1007/978-3-642-14139-3_5.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Walton, A. G., R. I. Bowles et F. T. Smith. « Vortex-Wave Interaction in a Strong Adverse Pressure Gradient ». Dans Instability, Transition, and Turbulence, 79–91. New York, NY : Springer New York, 1992. http://dx.doi.org/10.1007/978-1-4612-2956-8_9.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Hannappel, R., et R. Friedrich. « Interaction of Isotropic Turbulence with a Normal Shock Wave ». Dans Advances in Turbulence IV, 507–12. Dordrecht : Springer Netherlands, 1993. http://dx.doi.org/10.1007/978-94-011-1689-3_79.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Deleuze, J., et M. Elena. « Some Turbulence Characteristics Downstream a Shock Wave - Boundary Layer Interaction ». Dans Advances in Turbulence VI, 433–36. Dordrecht : Springer Netherlands, 1996. http://dx.doi.org/10.1007/978-94-009-0297-8_123.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Falcon, Eric. « Wave Turbulence : A Set of Stochastic Nonlinear Waves in Interaction ». Dans Understanding Complex Systems, 259–66. Cham : Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-10892-2_25.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Veltri, P., F. Malara et L. Primavera. « Nonlinear Alfvén Wave Interaction with Large-Scale Heliospheric Current Sheet ». Dans Nonlinear MHD Waves and Turbulence, 222–50. Berlin, Heidelberg : Springer Berlin Heidelberg, 1999. http://dx.doi.org/10.1007/3-540-47038-7_9.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Jacquin, L., E. Blin et P. Geffroy. « An Experiment on Free Turbulence/Shock Wave Interaction ». Dans Turbulent Shear Flows 8, 229–48. Berlin, Heidelberg : Springer Berlin Heidelberg, 1993. http://dx.doi.org/10.1007/978-3-642-77674-8_17.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Cho, Jungyeon. « Interaction of Wave Packets in MHD and EMHD Turbulence ». Dans Multi-scale Dynamical Processes in Space and Astrophysical Plasmas, 171–76. Berlin, Heidelberg : Springer Berlin Heidelberg, 2012. http://dx.doi.org/10.1007/978-3-642-30442-2_19.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Actes de conférences sur le sujet "Wave turbulence interaction"

Agostini, Lionel, Lionel Larcheveque et Pierre Dupont. « FEATURES OF SHOCK WAVE UNSTEADINESS IN SHOCK WAVE BOUNDARY LAYER INTERACTION ». Dans Eighth International Symposium on Turbulence and Shear Flow Phenomena. Connecticut : Begellhouse, 2013. http://dx.doi.org/10.1615/tsfp8.530.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Grube, Nathan, Ellen Taylor et Pino Martin. « Numerical Investigation of Shock-wave/Isotropic Turbulence Interaction ». Dans 49th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition. Reston, Virigina : American Institute of Aeronautics and Astronautics, 2011. http://dx.doi.org/10.2514/6.2011-480.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

HONKAN, A., et J. ANDREOPOULOS. « Experiments in a shock wave/homogeneous turbulence interaction ». Dans 21st Fluid Dynamics, Plasma Dynamics and Lasers Conference. Reston, Virigina : American Institute of Aeronautics and Astronautics, 1990. http://dx.doi.org/10.2514/6.1990-1647.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

CARROLL, B., et J. DUTTON. « Turbulence phenomena in a multiple normal shock wave/turbulent boundary layer interaction ». Dans 21st Fluid Dynamics, Plasma Dynamics and Lasers Conference. Reston, Virigina : American Institute of Aeronautics and Astronautics, 1990. http://dx.doi.org/10.2514/6.1990-1455.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Spanier, Felix. « Weak turbulence theory and wave-wave interaction : Three wave coupling in space plasmas ». Dans 2012 IEEE 39th International Conference on Plasma Sciences (ICOPS). IEEE, 2012. http://dx.doi.org/10.1109/plasma.2012.6383517.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Hickel, Stefan, O. C. Petrache et Nikolaus A. Adams. « TURBULENCE ENHANCEMENT BY FORCED SHOCK MOTION IN SHOCK-WAVE/TURBULENT BOUNDARY LAYER INTERACTION ». Dans Seventh International Symposium on Turbulence and Shear Flow Phenomena. Connecticut : Begellhouse, 2011. http://dx.doi.org/10.1615/tsfp7.1880.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Lee, Sangan, Sanjiva Lele et Parviz Moin. « Interaction of isotropic turbulence with a strong shock wave ». Dans 32nd Aerospace Sciences Meeting and Exhibit. Reston, Virigina : American Institute of Aeronautics and Astronautics, 1994. http://dx.doi.org/10.2514/6.1994-311.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Grube, Nathan, Ellen Taylor et Pino Martin. « Direct Numerical Simulation of Shock-wave/Isotropic Turbulence Interaction ». Dans 39th AIAA Fluid Dynamics Conference. Reston, Virigina : American Institute of Aeronautics and Astronautics, 2009. http://dx.doi.org/10.2514/6.2009-4165.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Diop, Moussa, Sebastien Piponniau et Pierre Dupont. « Transition mechanism in a shock wave boundary layer interaction ». Dans Tenth International Symposium on Turbulence and Shear Flow Phenomena. Connecticut : Begellhouse, 2017. http://dx.doi.org/10.1615/tsfp10.980.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Doveil, F., Y. Elskens, A. Ruzzon, A. Sen, S. Sharma et P. N. Guzdar. « Observation and Control of Hamiltonian Chaos in Wave-particle Interaction ». Dans INTERNATIONAL SYMPOSIUM ON WAVES, COHERENT STRUCTURES AND TURBULENCE IN PLASMAS. AIP, 2010. http://dx.doi.org/10.1063/1.3526149.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Rapports d'organisations sur le sujet "Wave turbulence interaction"

Fernando, H. J., et D. L. Boyer. Wave-Turbulence Interaction at an Inversion Layer. Fort Belvoir, VA : Defense Technical Information Center, décembre 1991. http://dx.doi.org/10.21236/ada244109.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Lee, S., P. Moin et S. K. Lele. Interaction of Isotropic Turbulence with a Shock Wave. Fort Belvoir, VA : Defense Technical Information Center, mars 1992. http://dx.doi.org/10.21236/ada250409.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Banner, Michael L., Russel P. Morison, William L. Peirson et Peter P. Sullivan. Turbulence Simulation of Laboratory Wind-Wave Interaction in High Winds and Upscaling to Ocean Conditions. Fort Belvoir, VA : Defense Technical Information Center, septembre 2012. http://dx.doi.org/10.21236/ada574611.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Friehe, Carl A. Wind-Turbulence-Wave Interactions. Fort Belvoir, VA : Defense Technical Information Center, septembre 2000. http://dx.doi.org/10.21236/ada610244.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Friehe, Carl A. Wind-Turbulence-Wave Interactions. Fort Belvoir, VA : Defense Technical Information Center, septembre 1999. http://dx.doi.org/10.21236/ada629664.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Friehe, Carl A. Wind-Turbulence-Wave Interactions. Fort Belvoir, VA : Defense Technical Information Center, août 2001. http://dx.doi.org/10.21236/ada625786.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Thomas, F. O. Experimental Investigation of Turbulence Behavior in Shock Wave/Turbulent Boundary Layer Interactions. Fort Belvoir, VA : Defense Technical Information Center, septembre 1991. http://dx.doi.org/10.21236/ada247792.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Melville, W. K. Interaction and Remote Sensing of Surface Waves and Turbulence. Fort Belvoir, VA : Defense Technical Information Center, septembre 1997. http://dx.doi.org/10.21236/ada628376.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Hara, Tetsu. Interaction Between Surface Gravity Waves and Near Surface Atmospheric Turbulence. Fort Belvoir, VA : Defense Technical Information Center, septembre 1997. http://dx.doi.org/10.21236/ada634931.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Livescu, Daniel, et Jaiyoung Ryu. Direct Numerical Simulations of isotropic turbulence interacting with a shock-wave. Office of Scientific and Technical Information (OSTI), mai 2013. http://dx.doi.org/10.2172/1079565.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Nous offrons des réductions sur tous les plans premium pour les auteurs dont les œuvres sont incluses dans des sélections littéraires thématiques. Contactez-nous pour obtenir un code promo unique!