Academic literature on the topic 'Simulations Euler-Lagrange'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Simulations Euler-Lagrange.'
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.
Journal articles on the topic "Simulations Euler-Lagrange":
1
Mast, Yannic, and Ralf Takors. "Transferring Bubble Breakage Models Tailored for Euler-Euler Approaches to Euler-Lagrange Simulations." Processes 11, no. 4 (March 27, 2023): 1018. http://dx.doi.org/10.3390/pr11041018.
Abstract:
Most bubble breakage models have been developed for multiphase simulations using Euler-Euler (EE) approaches. Commonly, they are linked with population balance models (PBM) and are validated by making use of Reynolds-averaged Navier-Stokes (RANS) turbulence models. The latter, however, may be replaced by alternate approaches such as Large Eddy simulations (LES) that play a pivotal role in current developments based on lattice Boltzmann (LBM) technologies. Consequently, this study investigates the possibility of transferring promising bubble breakage models from the EE framework into Euler-Lagrange (EL) settings aiming to perform LES. Using our own model, it was possible to reproduce similar bubble size distributions (BSDs) for EL and EE simulations. Therefore, the critical Weber (Wecrit) number served as a threshold value for the occurrence of bubble breakage events. Wecrit depended on the bubble daughter size distribution (DSD) and a set minimum time between two consecutive bubble breakage events. The commercial frameworks Ansys Fluent and M-Star were applied for EE and EL simulations, respectively. The latter enabled the implementation of LES, i.e., the use of a turbulence model with non-time averaged entities. By properly choosing Wecrit, it was possible to successfully transfer two commonly applied bubble breakage models from EE to EL. Based on the mechanism of bubble breakage, Wecrit values of 7 and 11 were determined, respectively. Optimum Wecrit were identified as fitting the shape of DSDs, as this turned out to be a key criterion for reaching optimum prediction quality. Optimum Wecrit values hold true for commonly applied operational conditions in aerated bioreactors, considering water as the matrix.
2
Askarishahi, Maryam, Mohammad-Sadegh Salehi, and Stefan Radl. "Voidage correction algorithm for unresolved Euler–Lagrange simulations." Computational Particle Mechanics 5, no. 4 (April 30, 2018): 607–25. http://dx.doi.org/10.1007/s40571-018-0193-8.
3
Kasbaoui, M. Houssem, Donald L. Koch, and Olivier Desjardins. "Clustering in Euler–Euler and Euler–Lagrange simulations of unbounded homogeneous particle-laden shear." Journal of Fluid Mechanics 859 (November 16, 2018): 174–203. http://dx.doi.org/10.1017/jfm.2018.796.
Abstract:
Particle-laden flows of sedimenting solid particles or droplets in a carrier gas have strong inter-phase coupling. Even at low particle volume fractions, the two-way coupling can be significant due to the large particle to gas density ratio. In this semi-dilute regime, the slip velocity between phases leads to sustained clustering that strongly modulates the overall flow. The analysis of perturbations in homogeneous shear reveals the process by which clusters form: (i) the preferential concentration of inertial particles in the stretching regions of the flow leads to the formation of highly concentrated particle sheets, (ii) the thickness of the latter is controlled by particle-trajectory crossing, which causes a local dispersion of particles, (iii) a transverse Rayleigh–Taylor instability, aided by the shear-induced rotation of the particle sheets towards the gravity normal direction, breaks the planar structure into smaller clusters. Simulations in the Euler–Lagrange formalism are compared to Euler–Euler simulations with the two-fluid and anisotropic-Gaussian methods. It is found that the two-fluid method is unable to capture the particle dispersion due to particle-trajectory crossing and leads instead to the formation of discontinuities. These are removed with the anisotropic-Gaussian method which derives from a kinetic approach with particle-trajectory crossing in mind.
4
Liu, Xu, Mingbo Sun, Hongbo Wang, Peibo Li, Chao Wang, Guoyan Zhao, Yixin Yang, and Dapeng Xiong. "A Heterogeneous Parallel Algorithm for Euler-Lagrange Simulations of Liquid in Supersonic Flow." Applied Sciences 13, no. 20 (October 12, 2023): 11202. http://dx.doi.org/10.3390/app132011202.
Abstract:
In spite of its prevalent usage for simulating the full-field process of the two-phase flow, the Euler–Lagrange method suffers from a heavy computing burden. Graphics processing units (GPUs), with their massively parallel architecture and high floating-point performance, provide new possibilities for high-efficiency simulation of liquid-jet-related systems. In this paper, a central processing unit/graphics processing unit (CPU/GPU) parallel algorithm based on the Euler–Lagrange scheme is established, in which both the gas and liquid phase are executed on the GPUs. To realize parallel tracking of the Lagrange droplets, a droplet dynamic management method is proposed, and a droplet-locating method is developed to address the cell. Liquid-jet-related simulations are performed on one core of the CPU with a GPU. The numerical results are consistent with the experiment. Compared with a setup using 32 cores of CPUs, considerable speedup is obtained, which is as high as 32.7 though it decreases to 20.2 with increasing droplets.
5
Kozic, Mirko, Slavica Ristic, Mirjana Puharic, and Boris Katavic. "Numerical simulation of multiphase flow in ventilation mill and channel with louvers and centrifugal separator." Thermal Science 15, no. 3 (2011): 677–89. http://dx.doi.org/10.2298/tsci101203018k.
Abstract:
This paper presents the results of numerical flow simulation in ventilation mill of Kostolac B power plant, where louvers and centrifugal separator with adjustable blade angle are used. Numerical simulations of multiphase flow were performed using the Euler-Euler and Euler-Lagrange approach of ANSYS FLUENT software package. The results of numerical simulations are compared with measurements in the mill for both types of separators. Due to very complex geometry and large number of the grid cells, convergent solution with the Eulerian model could not be obtained. For this reason the mixture model was employed resulting in very good agreement with measurements, concerning the gas mixture distribution and velocity at the main and secondary burners. There was large difference between the numerical results and measurements for the pulverized coal distribution at the burners. Taking into consideration that we analyzed dilute mixture with very low volume fraction of the coal, the only choice was the Euler-Lagrange approach, i.e. discrete phase model limited to volume fraction of the discrete phase less than 10-12%. Obtained distributions of the coal at the burners agree well for both types of separators.
6
Weber, Andreas, and Hans-Jörg Bart. "Flow Simulation in a 2D Bubble Column with the Euler-lagrange and Euler-euler Method." Open Chemical Engineering Journal 12, no. 1 (January 25, 2018): 1–13. http://dx.doi.org/10.2174/1874123101812010001.
Abstract:
Object: Bubbly flows, as present in bubble column reactors, can be simulated using a variety of simulation techniques. It is presented, how Computational Fluid Dynamics (CFD) methods are used to simulate a pseudo 2D bubble column using Euler-Lagrange (EL) and Euler-Euler (EE) techniques. Method: The presented EL method uses the open access software OpenFOAM to solve bubble dynamics with bubble interactions computed via Monte Carlo methods. The estimated bubble size distribution and the predicted hold-up are compared with experimental data and other simulative EE work with a reasonable consensus for both. Benchmarks with state of the art EE simulations shows that the EL approach shows good performance if the bubble number stays at a certain level, as the EL approach scales linearly with the number of bubbles simulated. Therefore, different computational meshes have been used to account for influence of the resolution quality. Conclusion: The EL approach indicated faster solution for all realistic cases, only deliberate decrease of coalescence rates could push CPU time to the limits. Critical bubble number - when EE becomes superior to the EL approach - was estimated to be 40.000 in this particular case.
7
Zhang, Shouxu, Weisheng Yan, and Guangming Xie. "Consensus-based leader-following formation control for a group of semi-biomimetic robotic fishes." International Journal of Advanced Robotic Systems 14, no. 4 (July 1, 2017): 172988141772078. http://dx.doi.org/10.1177/1729881417720784.
Abstract:
In this article, we developed a consensus-based leader-following formation control algorithm for a group of robotic fishes modeled by Euler–Lagrange dynamics. The Euler–Lagrange dynamics has been simplified as a second-order dynamics using the input transformation technique. Two consensus-based formation control strategies are discussed under the scenario: (1) leader with constant velocity and (2) leader with time-varying velocity. Three formation-keeping examples are shown in the simulations to verify the obtained formation control algorithm.
8
Tausendschön, Josef, Jari Kolehmainen, Sankaran Sundaresan, and Stefan Radl. "Coarse graining Euler-Lagrange simulations of cohesive particle fluidization." Powder Technology 364 (March 2020): 167–82. http://dx.doi.org/10.1016/j.powtec.2020.01.056.
9
Dhotre, M. T., N. G. Deen, B. Niceno, Z. Khan, and J. B. Joshi. "Large Eddy Simulation for Dispersed Bubbly Flows: A Review." International Journal of Chemical Engineering 2013 (2013): 1–22. http://dx.doi.org/10.1155/2013/343276.
Abstract:
Large eddy simulations (LES) of dispersed gas-liquid flows for the prediction of flow patterns and its applications have been reviewed. The published literature in the last ten years has been analysed on a coherent basis, and the present status has been brought out for the LES Euler-Euler and Euler-Lagrange approaches. Finally, recommendations for the use of LES in dispersed gas liquid flows have been made.
10
Song, Juan, and Shu Cai Li. "Study on Numerical Simulation of Explosion in Soil Based on Fluid-Solid Coupling Arithmetic." Applied Mechanics and Materials 580-583 (July 2014): 2916–19. http://dx.doi.org/10.4028/www.scientific.net/amm.580-583.2916.
Abstract:
Numerical simulations play a significant role in explosion in a mass of soil due to an underground explosive. Common methods available in hydrocode for fluid-solid coupling process are contact algorithm, Lagrange algorithm, and Arbitrary Lagrange-Euler (ALE) algorithm. A numerical simulation of explosion process with concentrated charge in a mass of soil was carried out by using three methods in this paper. The dynamic response of soil medium, the formation and development law of explosion cavity and the explosion wave propagation law in soil were simulated. Merits and drawbacks of three different methods are analyzed in the aspect of modeling, simulation results and computing cost.
Dissertations / Theses on the topic "Simulations Euler-Lagrange":
1
Senoner, Jean-Mathieu. "Simulations aux grandes échelles de l’écoulement diphasique dans un brûleur aéronautique par une approche Euler-Lagrange." Thesis, Toulouse, INPT, 2010. http://www.theses.fr/2010INPT0024/document.
Abstract:
Les turbines à gaz aéronautiques doivent satisfaire des normes d'émissions polluantes toujours en baisse. La formation de polluants est directement liée à la qualité du mélange d’air et de carburant en amont du front de flamme. Ainsi, leur réduction implique une meilleure prédiction de la formation du spray et de son interaction avec l'écoulement turbulent gazeux. La simulation aux grandes échelles (SGE) semble un outil numérique approprié pour étudier ces mécanismes. Le but de cette thèse est d’évaluer l'impact de modèles d'injection simplifiés sur la SGE de l'écoulement diphasique évaporant d’une configuration complexe. La configuration cible choisie est un brûleur aéronautique installé sur le banc expérimental MERCATO. Le banc expérimental est equipé d’un système d’injection d'air vrillé et d’un système d'injection liquide avec un atomiseur pressurisé swirlé représentatif de foyers aéronautiques réels. Dans un premier temps, un modèle d'injection simplifié pour atomiseurs pressurisés swirlés négligeant les effets de l'atomisation sur la dynamique du spray est présenté. L'objectif principal de ce modèle réside dans la reproduction de conditions d’injection similaires pour des traitements Eulériens et Lagrangiens de la phase particulaire. Dans un second temps, la composante Lagrangienne de ce modèle d'injection est combinée à un modèle d'atomisation secondaire de la litérature pour permettre une prise en compte partielle des phénomènes de pulvérisation liquide. Les SGE de l'écoulement diphasique évaporant de la configuration MERCATO présentées comportent deux aspects. Premièrement, différents modèles d’injection sont évalués pour quantifier leur impact sur la dynamique de la phase particulaire. Deuxièmement, une comparaison de simulations Euler-Euler et Euler-Lagrange reposant sur un modèle d'injection unifié est effectuéeAeroautical gas turbines need to satisfy growingly stringent demands on pollutant emission. Pollutant emissions are directly related to the quality of fuel air mixing prior to combustion. Therefore, their reduction relies on a more accurate prediction of spray formation and interaction of the spray with the gaseous turbulent flowfield. Large-Eddy Simulation (LES) seems an adequate numerical tool to predict these mechanisms. The objective of this thesis is to evaluate the impact of simplified injection methods on the LES of the evaporating two-phase flow inside a complex geometry. The chosen target configuration is an aeronautical combustor installed on the MERCATO test-rig. The experimental setup includes an air-swirler injection system and a pressureswirl atomizer typical of realistic aeronautic combustors. In a first step, a simplified injection model for pressure swirl atomizers neglecting the impact of liquid disintegration on spray dynamics is presented. The main objective of this model lies in the reproduction of similar injection conditions for Eulerian and Lagrangian representations of the dispersed phase. In a second step, the Lagrangian injection method is combined to a secondary breakup model of the literature to partly account for the liquid disintegration process. The presented LES’s of the evaporating two-phase flow inside the MERCATO geometry consider two different aspects. First, the impact of injection modeling on spray dynamics is assessed. Second, Euler-Euler and Euler-Lagrange simulations relying on the common simplified injection model are compared
2
Hannebique, Grégory. "Etude de la structure des flammes diphasiques dans les brûleurs aéronautiques." Thesis, Toulouse, INPT, 2013. http://www.theses.fr/2013INPT0026/document.
Abstract:
La régulation des polluants a mené à la création de nouveaux systèmes de combustion. Le carburant étant stocké sous forme liquide, sa transformation jusqu’à sa combustion est complexe. La capacité de la Simulation aux grandes échelles à simuler des écoulements turbulents réactifs a été montrée sur des cas académiques comme sur des configurations industrielles, tout en prenant en compte les phénomènes multiphysiques intervenant dans ces configurations, mais les études sur la structure de flamme diphasique sont encore trop peu nombreuses. La présence de deux solveurs pour la simulation d’une phase liquide étant disponible dans le code AVBP, leur utilisation permet une comparaison et une compréhension des phénomènes en jeu combinant dispersion, évaporation, et combustion. La première partie de l’étude relate la validation du modèle d’injection FIM-UR. Ce modèle est capable de reconstruire les profils de vitesses et de granulométrie à l’injecteur sans avoir à simuler les phénomènes d’atomisation primaire et secondaire. Une validation en régime turbulent avait déjà été réalisée, et on propose ici de valider le modèle dans un cas laminaire. Des comparaisons entre simulations monodisperses et polydisperse et des expériences sont effectuées. La simulation monodisperse Lagrangienne donne une bonne structure globale mais la simulation polydisperse Lagrangienne permet de retrouver le comportement au centre du cône avec la présence des petites gouttes et à la périphérie du cône par la présence des grosses gouttes. De plus, des améliorations sont apportées au modèle pour le formalisme Eulérien et montrent de bons résultats. La partie suivante s’intéresse à caractériser un spray polydisperse par une distribution monodisperse. En effet, au cas où une approche polydisperse n’est pas possible, le choix du diamètre moyen à prendre pour une simulation monodisperse est délicat. On propose donc d’analyser le comportement d’un spray polydisperse en le comparant à ceux de sprays monodisperses. Deux configurations académiques sont choisies : des cas de Turbulence Homogène Isotrope chargée en particules pour étudier la dynamique, et des calculs d’évaporation 0D. Trois paramètres sont étudiés pour la dynamique : la concentration préférentielle (ou ségrégation), la traînée moyenne et la traînée réduite moyenne. Cette dernière et la ségrégation de la distribution polydisperse semblent affectées par les tailles de goutte les plus faibles, et la concentration préférentielle apparait alors comme la moyenne des ségrégations des classes qui la composent pondérées par l’inverse du nombre de Stokes associé à chacune de ces classes. La traînée moyenne de la simulation polydisperse possède un comportement proche des diamètres moyens D10 et D20. Ces analyses nous poussent donc à choisir le D10 pour caractériser la dynamique d’un spray polydisperse. Les calculs d’évaporation 0D ne permettent pas dans un premier temps de caractériser efficacement la masse évaporée d’un spray polydisperse par celle d’un spray monodisperse équivalent, mais la définition de nouveaux diamètres issus de la littérature des lits fluidisés comme le D50% le permet, ce qui le place autour du D32. On propose donc de caractériser l’évaporation d’un spray polydisperse par ce diamètre. Enfin, la dernière partie étudie la structure de flamme diphasique dans la chambre MERCATO, à l’aide du formalisme Lagrangien, monodisperse et polydisperse, mais aussi en utilisant le formalisme Eulérien. La validation du modèle FIM-UR du premier chapitre et ses améliorations sont utilisées pour représenter les conditions d’injection liquide. En plus d’un calcul polydisperse, deux simulations monodisperses Lagrangiennes sont réalisées en prenant les diamètres moyens D10 et D32, suite à la partie précédente. Des comparaisons qualitatives et des validations sont réalisées, en comparant des profils de vitesses gazeuses axiale et fluctuante et vitesse axiale liquide issus de l’expérienceRegulations on pollutants have led to the creation of new combustion systems. Giving that fuel is stored in a liquid form, its evolution until combustion is complex. The ability of Large Eddy Simulation has been demonstrated on academic cases, as well as on industrial configurations, by taking into account the multi-physics phenomena, but there is a lack of studies about two-phase flow flame structures. Two solvers for the simulation of two-phase flows are available in the AVBP code, hence both simulations are performed to compare and increase understanding of the phenomena involved such as dispersion, evaporation and combustion. The first part of the study focuses on the validation of the FIM-UR injection model. This model is able to build velocity and droplet profiles at the injector, without simulating primary and secondary break up. A validation in a turbulent case has already been done, and this study validates the model in a laminar case. Comparisons between monodisperse and polydisperse simulations, and experiments are performed. The monodisperse Lagrangian simulation shows good results but the polydisperse simulation is able to represent profiles in the center of the cone by small droplets and at the peripheral part of the cone, by big ones. Moreover, improvements in the Eulerian model exhibit good results. The next section tries to evaluate the impact of polydispersion. Indeed, when a polydisperse approach is not available, choosing the mean diameter can be tricky. A comparison between the behavior of polydisperse spray and monodisperse sprays ones is realised. Two academic cases are studied: Homogeneous Isotropic Turbulence with particles to analyze the dynamics, and 0D evaporation cases. For the dynamics, preferential concentration, mean drag and reduced mean drag are studied. The latter and preferential concentration are affected by small droplets, and the preferential concentration of a polydisperse spray is equivalent to the average of preferential concentration of classes, extracted from the polydisperse distribution, weighted by the inverse of the Stokes number of each class. The mean drag behaves like the D10 and D20 mean drags. This analysis allows us to choose the D10 to characterize a polydisperse distribution for the dynamics. Zero-D evaporation simulations cannot characterize the polydisperse spray evaporated mass by the evaporated mass of monodisperses sprays. New definitions of diameters from fluidized bed literature enable the use of D50%, which is close to D32. We propose to use this diameter to characterize the evaporation of a polydisperse spray. Finally, the last section studies the structure of two-phase flames in the MERCATO bench, using the Lagrangian formalism, monodisperse and polydisperse but also using the Eulerian formalism. The validation of FIM-UR model and improvements from the first section are used to represent liquid injection conditions. A polydisperse simulation is realized and two monodisperse simulations are computed using mean diameters D10 and D32, thanks to the previous section. Qualitative comparisons and validations are realized, comparing gaseous velocity profiles and liquid velocity profiles. Good agreements are found and the mean diameter D32 seems to be close to the polydisperse spray. A comparison between mean flames is done with an Abel transform of the flame from the experiments. The flame has an "M shape", anchored by small recirculation zones out of the swirler, and by a point at the tip of the central recirculation zone. Then, the impact of droplet distributions is analyzed. Even if few bigger droplets from the polydisperse distribution are convected in the hot gases due to bigger particular time and evaporation time, two-phase flow flame structures are equivalent. Different combustion regimes appeared with premixed flames and pockets of fuel burning in the hot gases
3
Ali, Abd El Aziz Essa Mohamed. "COUPLED LAGRANGE-EULER MODEL FOR SIMULATION OF BUBBLY FLOW IN VERTICAL PIPES CONSIDERING TURBULENT 3D RANDOM WALKS MODELS AND BUBBLES INTERACTION EFFECTS." Doctoral thesis, Universitat Politècnica de València, 2012. http://hdl.handle.net/10251/18068.
Abstract:
Una nueva aproximación euleriana-lagarangiana, en su forma de acople en dos vías, para la simulación de flujo de burbujas, agua-aire es presentada en la tesis, en la que se incluyen los efectos de las colisiones entre burbujas, así como las posibles roturas o coalescencia de burbujas. Esta aproximación utiliza el modelo Continuous Random Walk, CRW, para tener en cuenta las fluctuaciones de la velocidad. Esta aproximación se enmarca dentro de un modelo de turbulencia k-epsilon para la fase continua del líquido. En esta tesis se estudiarán los métodos para realizar el acople entre ambas aproximaciones, el efecto de la fuerza lift y de la dispersión turbulenta sobre la distribución de la fracción de huecos, así como los modelos de coalescencia y rotura de burbujas que puedan ser empleados en este tipo de aproximación.
Se ha partido de un código euleriano para simular la parte continua, y sobre él se ha acoplado la aproximación lagrangiana. Para que ese acople afecte a la fase continua sobre su solver ser han añadido fuentes de momento y turbulencia. Además se ha modificado el volumen computacional de cada celda para que tenga en consideración el volumen ocupado por la fase dispersa. El acople en doble vía hace que los perfiles de velocidad y turbulencia de la fase continua se modifiquen notablemente y que se aproximen a los reales, lo que resulta básico para la correcta simulación de las fuerzas interfaciales.
La colisión entre burbujas, y burbujas y pared se ha incluido. Este efecto es necesario como paso previo a incluir los procesos de rotura o coalescencia de burbujas, aunque la colisión en sí tenga efectos limitados en la distribución de la fracción de huecos. El proceso de coalescencia se basa en el modelo de Chester ( 1991 ) , el modelo compara el tiempo de colisión con el tiempo de drenaje de la película entre burbujas para determinar si existe o no coalescencia. El modelo de rotura se basa en el modelo de Martínez-Bazán.
Uno de los principales hitos deAli Abd El Aziz Essa ., M. (2012). COUPLED LAGRANGE-EULER MODEL FOR SIMULATION OF BUBBLY FLOW IN VERTICAL PIPES CONSIDERING TURBULENT 3D RANDOM WALKS MODELS AND BUBBLES INTERACTION EFFECTS [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/18068
Palancia
4
Pérard-Lecomte, Aude. "Caractérisation de la dispersion des polluants particulaires dans le sillage des poids lourds en milieu urbain." Electronic Thesis or Diss., Université de Lorraine, 2023. http://www.theses.fr/2023LORR0207.
Abstract:
Le transport routier est un contributeur majeur à la dégradation de la qualité de l'air en zone urbaine, et notamment en particules fines et ultrafines. Ces dernières sont néfastes pour la santé des citadins, pouvant aggraver voire causer des pathologies pulmonaires et cardio-vasculaires. Dans le cadre de cette thèse, on s'intéresse alors à l'évolution des particules issues des échappements des poids lourds, à partir de leur émission. L'objectif principal de cette thèse consiste à mettre en lumière l'étendue de la dispersion des particules émises autour et dans le sillage d'un poids lourd. Des méthodes numériques basées sur une approche Euler-Lagrange ont alors été utilisées afin de simuler et de caractériser la topologie de l'écoulement d'air autour du camion, par l'approche RANS (Reynold-Averaged Navier-Stokes), puis la phase dispersée, par une approche lagrangienne. Ces simulations ont été supportées par des mesures en soufflerie, dans le sillage d'un modèle de poids lourd à échelle réduite. La PIV (Particle Image Velocimetry) a été utilisée pour l'analyse des champs de vitesse de l'air, tandis que la dispersion de particules solides ultrafines a été caractérisée au travers de la mesure des champs de concentrations par granulomètre. L'écoulement de sillage du poids lourd est totalement détaché au niveau de la paroi arrière de celui-ci, faisant apparaître une zone de recirculation principalement composée d'un large tourbillon qui se forme à partir de l'écoulement provenant du dessous de la remorque. La dynamique des particules émises par les échappements des poids lourds apparaît comme étant fortement corrélée aux structures tourbillonnaires présentes notamment dans son sillage. En effet, les particules tendent à se concentrer préférentiellement sur la périphérie du tourbillon principal, ainsi que dans les zones de faible intensité turbulente. Le mouvement des particules les plus inertielles (diamètre > 2,5~mu m) est dominé par la gravité, tandis que c'est la turbulence qui est principalement responsable du mouvement et du dépôt des particules les plus fines (diamètre < 2,5~mu m). La position et l'orientation du pot d'échappement ont également une influence considérable sur l'étendue de la dispersion et la répartition des particules dans le sous-bassement et le sillage du poids lourd. En effet, lorsque les particules sont émises par le dessous du poids lourd, elles se concentrent en majorité dans la zone de recirculation, à moins de 1,85H (H étant la hauteur de la remorque), et à hauteur humaine. A l'inverse, les particules émises par le dessus du poids lourd ne sont qu'en très faible part ré-entraînées dans la zone de recirculation et se concentrent au dessus de celle-ci, soit à l'équivalent de 2,6~m (0,9H) du sol. L'exposition des différentes populations aux particules émises par les poids lourds pourrait alors être fortement limitée quand les échappements sont libérés sur le dessus du poids lourd, dans des conditions similaires de roulageRoad transportation is a major contributor to air quality pollution in urban areas, particularly in fine and ultrafine particles. These pollutants are harmful to human health, as they can worsen or cause lung and cardiovascular diseases. In this context, we are interested in the evolution of particles emitted from heavy truck exhausts, starting from their emission. The main objective of this thesis is to study the extent of particle dispersion emitted by heavy truck's exhausts, around and in the wake of heavy trucks. Numerical methods based on an Euler-Lagrange approach were used to simulate and characterize the airflow topology around the truck, using the Reynolds-Averaged Navier-Stokes (RANS) method for the fluid phase and a Lagrangian approach for the dispersed phase. These simulations were supported by wind tunnel measurements in the wake of a reduced-scale model of a heavy truck. Particle Image Velocimetry (PIV) was used for analyzing the air velocity fields, while the dispersion of ultrafine solid particles was characterized by measuring concentration fields using a granulometer. The truck's wake flow is completely detached at the rear of the trailer, revealing a recirculation zone mainly composed of a large vortex, coming from the under-trailer. Particles' dynamics appears to be dominated by turbulence and strongly correlated with vortical structures, especially in the wake of the truck. Indeed, particles tend to concentrate preferentially on the periphery of the main vortex formed behind the truck, as well as in areas of low turbulent intensity. The movement of most inertial particles (diameter > 2.5~mu m) is dominated by gravity, while turbulence is mainly responsible for the movement and deposition of the finest particles (diameter < 2.5~mu m). The position and orientation of the exhaust pipe also have a significant influence on the extent of dispersion and the distribution of particles in the underbody and in the wake of the heavy truck. Indeed, when particles are emitted from the under-trailer, most of them are concentrated in the recirculation zone, less than 1.85H away from the trailer (H being the height of the trailer), and at human height. On the other hand, the particles emitted on the top of the truck are very rarely re-entrained in the recirculation zone, and are mostly concentrated above it, at a height equivalent to 2.6~m (0,9H) above ground level. The exposure of populations to the particles emitted by heavy goods vehicles could therefore be sharply limited when the exhausts are released from top of the truck
5
Divaret, Lise. "U-RANS Simulation of fluid forces exerted upon an oscillating tube array." Thesis, KTH, Farkost och flyg, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-32747.
Abstract:
The aim of this master thesis is to characterize the fluid forces applied to a fuel assembly inthe core of a nuclear power plant in case of seism. The forces are studied with a simplifiedtwo-dimensional model constituted of an array of 3 by 3 infinite cylinders oscillating in aclosed box. The axial flow of water, which convects the heat in the core of a nuclear powerplant, is also taken into account. The velocity of the axial flow reaches 4m/s in the middle ofthe assembly and modifies the forces features when the cylinders move laterally.The seism is modeled as a lateral displacement with high amplitude (several cylinderdiameters) and low frequencies (below 20 Hz). In order to study the effects of the amplitudeand of the frequency of the displacement, the displacement taken is a sine function withboth controlled amplitude and frequency. Four degrees of freedom of the system will bestudied: the amplitude of the displacement, its frequency, the axial velocity amplitude andthe confinement (due to the closed box).The fluid forces exerted on the cylinders can be seen as a combination of three terms: anadded mass, related to the acceleration of cylinders, a drift force, related to the damping ofthe fluid and a force due to the interaction of the cylinder with residual vortices. The firsttwo components will be characterized through the Morison expansion, and their evolutionwith the variation of the degree of freedom of the system will be quantified. The effect ofthe interaction with the residual vortices will be observed in the plots of the forces vs. timebut also in the velocity and vorticity map of the fluid.The fluid forces are calculated with the CFD code Code_Saturne, which uses a second orderaccurate finite volume method. Unsteady Reynolds Averaged Navier Stokes simulations arerealized with a k-epsilon turbulence model. The Arbitrary Lagrange Euler model is used todescribe the structure displacement. The domain is meshed with hexahedra with thesoftware gmsh [1] and the flow is visualized with Paraview [2]. The modeling techniquesused for the simulations are described in the first part of this master thesis.
6
Vessiller, Cédric. "Contribution à l'étude des brouillards denses et dilués par la simulation numérique Euler-Euler et Euler-Lagrange." Châtenay-Malabry, Ecole centrale de Paris, 2008. http://www.theses.fr/2008ECAP1112.
Abstract:
Dans les moteurs Diesel à injection directe, la combustion est contrôlée par lescaractéristiques de l'atomisation d'une part, et par celles du spray formé par l'injecteur d'autre part. Les études expérimentales et numériques ont montré que la transition entre la région du coeur liquide dense à la sortie de l'injecteur, et la partie dispersée du spray en aval de l'écoulement, est pilotée par des mécanismes complexes incluant la cavitation dans l'injecteur, les instabilités aérodynamiques à la surface du jet et la turbulence. Ce travail a pour objectif l'élaboration d'un modèle d'atomisation fondé sur une description eulérienne de l'écoulement diphasique issu de l'injecteur. Le modèle bifluide eulérien met en jeu un système d'équations de bilan pour la phase liquide et la phase gazeuse composée du gaz et de la vapeur du carburant. La valeur de la densité d'aire interfaciale par unité de volume est obtenue par une équation de transport supplémentaire qui comporte dans son second membre des termes de production et de destruction de surface d'échange. On utilise aussi une équation de transport pour la fraction volumique de liquide. Ces deux quantités permettent de déterminer les caractéristiques locales du spray et de déduire les termes d'échange interfaciaux entre les deux phases. Des calculs réalisés dans des configurations représentatives de l'injection Diesel montrent un bon accord entre les longueurs de pénétration de la phase liquide obtenues numériquement et les valeurs relevées expérimentalement. Les calculs en condition évaporantes ne donnent cependant pas les résultats escomptés et des pistes pour résoudre les problèmes liés à l'évaporation sont proposéesThe present work particularly focuses on direct injection engines, in which combustion is determined by the characteristics of theatomisation and of the fuel spray produced by the nozzle. Previous experimental and numerical studies show that transition between the dense liquid region at the nozzle exit and the domain where the liquid is dispersed is governed by a range of mechanisms including cavitation inside the injector, aerodynamic instabilities, and turbulence. This report describes the development of an atomisation model for eulerian description of two-phase flows produced by nozzles. The eulerian-eulerian description includes a system of balance equations for each phase:liquid fuel and gas (fuel vapour and air). The amount of interfacial area perunit volume between the gas and the liquid is obtained from a balance equation whose source terms figuring on the rightand side account for production and destruction of interfacial area. A balance equation for the void fraction is used too. Both quantities allow to calculate local spray characteristics from which are deduced interfacial exchange terms between both phases. Various numerical test cases have been carried out to check the numerical implementation of the model while the simulation of droplet laden jets showed the ability of the model to deal with two-phase flows. The model is then validated against experimental results with comparisons of phase penetration in high pressure test cells under conditions close to those prevailing in direct injection diesel engines. Numerical results in evaporating conditions do not follow experimental trends but possibilities to solve the remainaining problems are proposed
7
Weber, Andreas [Verfasser]. "Simulating bubble movement with the Euler-Lagrange approach / Andreas Weber." München : Verlag Dr. Hut, 2018. http://d-nb.info/117442690X/34.
8
Wysocki, Stefan. "Joint Euler-Lagrange method for moving surfaces in large-eddy simulation." Thesis, Imperial College London, 2012. http://hdl.handle.net/10044/1/10214.
Abstract:
Continuous growth of computing power strongly encourages engineers to rely more on computational fluid dynamics for the design and testing of new technological solutions. The fast development of these new tools goes along with the increasing availability of high-performance computers, which are necessary to simulate realistic industrial applications. The presented immersed boundary (IB) method is applicable to simple and complex geometries with static and moving boundaries, where fluids interact with the solid structures. The formulation of the method is based on the Eulerian and Lagrangian principles and its key characteristics are its simple formulation and computational efficiency. Furthermore the nature of the method allows the simulations of flows in complex geometries without having to generate complex meshes. The spatial discretization is based on a fixed Cartesian mesh for the Eulerian variables and boundary movements are tracked with Lagrangian particles. Large- Eddy simulations of flows in simple and complex geometries demonstrate the performance of the applied immersed boundary method. Simple cases include the simulation of an isothermal pipe flow and the flow around a sphere. In the first instance, the fluid flows around a static sphere. In the second case the sphere moves relative to the grid for identical flow conditions. Simulations of complex geometries include the investigation of an isothermal and reactive opposed jet flow with perforated and fractal grids. The simulations require cell sizes near the resolution of direct numerical simulations. The injection phase of a piston-cylinder arrangement, assuming constant pressure, is also investigated with the proposed IB method. Good statistical results for first and second moments are achieved for all investigated cases, although the applied grids have to be fine enough to accurately resolve the wall shear stresses. In addition, the concept of using Lagrangian particles has been applied to immiscible flows. Particles are used to improve the accuracy of scalar transport and initial results of simple, two-dimensional test cases are presented.
9
Hu, Guanghui. "Numerical simulations of the steady Euler equations on unstructured grids." HKBU Institutional Repository, 2009. http://repository.hkbu.edu.hk/etd_ra/1106.
10
Baraglia, Federico. "Développement d'un modèle triphasique Euler/Euler/Lagrange pour la simulation numérique des écoulements liquide-gaz chargés en particules." Electronic Thesis or Diss., Université de Toulouse (2023-....), 2024. http://www.theses.fr/2024TLSEP017.
Abstract:
Ce manuscrit retranscris un travail effectué au cours d’une thèse au département MFEE d’EDF R&D sur les écoulements liquid-gaz chargés en particules dispersées sous la direction d’Olivier Simonin (IMFT), de Jérôme Laviéville (EDF) et de Nicolas Mérigoux (EDF). Le but de la thèse est de fournir un environnement de travail pour la simulation numérique d’écoulement eau-air à bulles, à phases séparés ou en régime mixte, chargé en particules qui peuvent interagir avec les fluides présents sous leur forme continue ou dispersée. Ces écoulements peuvent se retrouver aussi bien dans des situations industrielles comme des réacteurs chimiques, des centrales de production d’électricité ou des usines de traitement des eaux usées que dans des situations naturelles comme durant la crue d’un fleuve. L’outil développé permet de faire des prédictions sur les performances de ces dispositifs industriels ou sur les dégâts causés par des évènements naturels exceptionnels. Les développements sont inclus dans la version la plus à jour du code de calcul neptune_cfd, un solveur N-fluides développé par EDF, le CEA, l’IRSN et Framatome, basé sur la méthode multi-fluide standard qui permet la simulation d’écoulement à plusieurs phases indépendamment de leur typologie.Les méthodes misent en place sont basées sur des approches diphasiques bien connues. La méthode Lagrangienne stochastique de suivi de particules est adaptées pour que chaque particule puisse interagir avec toutes les champs fluides présents. Des fermetures sont proposées pour déterminer l’impact de chacune des phases sur le comportement des particules. Afin de vérifier certaines hypothèses, une nouvelle fermeture pour l’équation de Langevin sur la vitesse de fluide vue par la particule est proposée. Son comportement est comparée aux modèles standards et de la littérature sur des cas de vérification simples de turbulence homogène isotrope et des cas inhomogènes. Les équations Lagrangiennes obtenues sont utilisées pour fermer un modèle Eulerien basé sur l’approche fonction densité de probabilité. Les performances des deux modèles triphasiques développés sont établies en matière de déposition de particules pilotée par la turbulence et la gravité.Un pan entier de la thèse se concentre sur une problématique apparue durant des vérifications préliminaires: le phénomène d’entraînement d’air dans les jets plongeants. En effet, à partir d’une structure résolue, en fonction des conditions d’écoulements, des bulles ou gouttelettes dispersées peuvent apparaître. La quantité de ces structures transférées ainsi que leur taille caractéristique étant des grandeurs primordiales, il a fallu mettre en place un nouveau modèle. Le transfert de masse entre structures continues et inclusions dispersées est assuré par le modèle qui décrit l’évolution des interfaces résolues. Nous ne l’avons pas modifié. Celui qui concerne la taille des bulles/gouttelettes créées s’intègre dans l’équation d’évolution de l’aire interfaciale, grandeur qui permet de suivre le diamètre des inclusions.Tous les modèles développés sont comparés à des mesures expérimentales. Le modèle d’entraînement d’air est d’abord testé sans la présence des particules sur des cas divers. Un cas de ressaut hydraulique est aussi envisagé pour établir la généralité du modèle mis en place. Les modèles triphasiques sont testés sur des configurations variées, d’abord sans entraînement d’air pour isoler le comportement des particules puis avec tous les phénomènes. Les différents cas ont permis de mettre en valeur l’importance de certains modèles ainsi que les différences entre les méthodes Lagrangienne stochastique et EulerienneThis manuscript sums up work carried out during a thesis at the MFEE department of EDF R&D on liquid-gas flows laden with dispersed particles under the supervision of Olivier Simonin (IMFT), Jérôme Laviéville (EDF), and Nicolas Mérigoux (EDF). The thesis aims at providing a working environment for the numerical simulation of two-phase bubbly flows, free-surface flows or in a mixed regime, loaded with particles that can interact with the fluids present in their continuous or dispersed form. These flows can be found in industrial situations such as chemical reactors, power plants, or wastewater treatment plants, as well as in natural situations such as during a flood. The developed tool allows predictions to be made about the performance of these industrial devices or the damage caused by exceptional natural events. The developments are included in the most up-to-date version of neptune_cfd, a multi-fluid solver developed by EDF, CEA, IRSN, and Framatome, based on the standard multi-fluid method that allows the simulation of multiphase flow independently of their typology.The methods implemented are based on well-known two-phase approaches. The stochastic Lagrangian particle tracking method is adapted so that each particle can interact with all the fluids. Closures are proposed to determine the impact of each phase on the behavior of the particles. To verify certain assumptions, a new closure for the Langevin equation on the fluid velocity seen by the particle is proposed. Its behavior is compared to standard models and literature on simple verification cases of homogeneous isotropic turbulence and inhomogeneous cases. The Lagrangian equations obtained are used to close an Eulerian model based on the probability density function approach. The performance of the two developed threephase models is established in terms of particle deposition driven by turbulence or gravity.A significant part of the thesis focuses on an issue that arose during preliminary checks: the phenomenon of air entrainment in plunging jets. Indeed, due to the nature of the solver, bubbles or dispersed droplets can detach from the free-surface depending on the flow conditions. The quantity of these transferred structures and their characteristic size being crucial quantities which drives their behavior, a new model had to be developed. Mass transfer between continuous structures and dispersed inclusions is ensured by the model that describes the evolution of resolved interfaces, the latter was not modified. The one regarding the size of the created bubbles/droplets is integrated into the evolution equation of the interfacial area, a quantity that allows tracking the diameter of the inclusions.All developed models are compared to experimental measurements. The air entrainment model is first tested without the presence of particles in various cases. A hydraulic jump case is also considered to establish the generality of the model. Then, the threephase models are tested in various configurations. First, configurations without air entrainment to isolate the behavior of the particles, and then with air entrainment. The different cases highlighted the importance of certain models and the differences between stochastic Lagrangian and Eulerian methods
Books on the topic "Simulations Euler-Lagrange":
1
Center, NASA Glenn Research, ed. Finite element simulation of a space shuttle solid rocket booster aft skirt splashdown using an arbitrary Lagrangian-Eulerian approach. [Cleveland, Ohio: NASA Glenn Research Center, 2003.
2
J, Yu N., and United States. National Aeronautics and Space Administration. Scientific and Technical Information Branch., eds. Flow prediction for propfan engine installation effects on transport aircraft at transonic speeds. [Washington, D.C.]: National Aeronautics and Space Administration, Scientific and Technical Information Branch, 1986.
3
Atomization simulations using an Eulerian-VOF-Lagrangian method. [Washington, DC: National Aeronautics and Space Administration, 1994.
4
Finite element simulation of a space shuttle solid rocket booster aft skirt splashdown using an arbitrary Lagrangian-Eulerian approach. [Cleveland, Ohio: NASA Glenn Research Center, 2003.
Book chapters on the topic "Simulations Euler-Lagrange":
1
Spitzenberger, Andy, Katrin Bauer, and Rüdiger Schwarze. "Reactive Cleaning and Active Filtration in Continuous Steel Casting." In Multifunctional Ceramic Filter Systems for Metal Melt Filtration, 427–52. Cham: Springer International Publishing, 2024. http://dx.doi.org/10.1007/978-3-031-40930-1_17.
Abstract:
AbstractBasic fluid dynamic processes of melt filtration have been investigated in order to increase the performance and efficiency of filtration systems in steelmaking, especially for continuous steel casting. Numerical simulations have been performed to investigate the interactions between filter structures and the mean melt flow, the development of endogenous non-metallic inclusion (NMI) populations in the flow, and inclusion removal from the melt. For this purpose, Euler–Lagrange models of the particle-laden flow have been developed. As a major finding, the reactive cleaning process of the melt has been proven to be a very efficient cleaning method. Here, inclusion removal is strongly improved by the lifting action of reactively generated gas bubbles at the NMI surfaces. Details of the reactive cleaning process and the combination of reactive cleaning and active filtration have been investigated, too. The prediction quality of the numerical models with regard to fluid flow and the efficiency of the employed filtration systems have been successfully examined by comparing numerical simulations with the results from experimental investigations in different water model experiments and the steel casting simulator.
2
Neumann, Sebastian, Amjad Asad, and Rüdiger Schwarze. "Numerical Simulation of Continuous Steel Casting Regarding the Enhancement of the Cleanliness of Molten Steel." In Multifunctional Ceramic Filter Systems for Metal Melt Filtration, 769–85. Cham: Springer International Publishing, 2024. http://dx.doi.org/10.1007/978-3-031-40930-1_30.
Abstract:
AbstractResearch results of this chapter show a great potential to improve inclusion removal from steel melts using active and reactive exchangeable filtration systems in steelmaking. This contribution investigates numerically the performance and the efficiency of the reactive cleaning and active filtration in continuous casting tundishes. For this purpose, a Euler–Lagrange model of the disperse two-phase flow of steel melt and non-metallic inclusions has been developed. Here, implicit large eddy simulations have been employed to resolve the large-scale turbulent structures in the tundish flows. By means of multiphase flow simulations, two prototype tundish configurations (laboratory one-strand tundish, industrial-scale two-strand tundish) were researched with alumina-coated, carbon-bonded ceramic foam hybrid filters. The research aimed the investigation of the effect of the filtration system, e.g. filter position, filter shapes and filter size on inclusion removal. The results of the numerical simulations indicated the high cleaning efficiencies obtained by using a reactive filter system, where reactively generated carbon monoxide bubbles carried a high amount of inclusions to the slag. Moreover, it was concluded from the results that the contribution of active filtration to inclusion removal by the deposition of inclusions on filter surfaces was neglectable compared to the contributions of reactive cleaning.
3
Abdul Quiyoom, Vivek V. Buwa, and S. K. Ajmani. "Euler-Lagrange Simulations of Gas-Liquid Flow in a Basic Oxygen Furnace and Experimental Verification." In Fluid Mechanics and Fluid Power – Contemporary Research, 1151–61. New Delhi: Springer India, 2016. http://dx.doi.org/10.1007/978-81-322-2743-4_109.
4
Rao, J. S. "Euler-Lagrange Equations." In Simulation Based Engineering in Solid Mechanics, 83–100. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-47614-8_3.
5
Vincent, Stéphane, Jean-Luc Estivalézes, and Ruben Scardovelli. "Multiscale Euler–Lagrange Coupling." In Small Scale Modeling and Simulation of Incompressible Turbulent Multi-Phase Flow, 263–91. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-09265-7_9.
6
Liu, Hui, Markus Meurer, and Thomas Bergs. "Three-Dimensional Modeling of Thermomechanical Tool Loads During Milling Using the Coupled Eulerian-Lagrangian Formulation." In Lecture Notes in Production Engineering, 318–30. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-34486-2_23.
Abstract:
AbstractMilling is a complex process where machining quality is influenced by tool geometry, chip flow, temperature, and wear. In recent years, the rapid development of computer technology has enabled the use of finite element simulation methods to study the relationship between the machining results and various process parameters. In this study, a three-dimensional thermal coupled Euler-Lagrange milling model is proposed. This approach provided unique advantages in terms of stability and computational speed. The simulation results showed a good agreement with the corresponding experimental cutting tests and provided further information on the heat source distribution characteristics, which form a basis for further theoretical investigations.
7
Taborda, Manuel A., and Martin Sommerfeld. "Elongated Non-spherical Particles in Turbulent Channel Flow Using Euler/Lagrange Approach." In Direct and Large Eddy Simulation XIII, 264–72. Cham: Springer Nature Switzerland, 2023. http://dx.doi.org/10.1007/978-3-031-47028-8_41.
8
Khalifa, Ali, and Michael Breuer. "Euler-Lagrange LES Predictions of a Powder Disperser Including a Multiscale Wall-Impact Breakage Model." In Direct and Large Eddy Simulation XIII, 89–94. Cham: Springer Nature Switzerland, 2023. http://dx.doi.org/10.1007/978-3-031-47028-8_14.
9
Führer, C., and B. Leimkuhler. "A New Class of Generalized Inverses for the Solution of Discretized Euler — Lagrange Equations." In Real-Time Integration Methods for Mechanical System Simulation, 143–54. Berlin, Heidelberg: Springer Berlin Heidelberg, 1990. http://dx.doi.org/10.1007/978-3-642-76159-1_8.
10
Lempke, Markus, Peter Gerlinger, Michael Rachner, and Manfred Aigner. "Euler-Lagrange Simulation of a LOX/H2 Model Combustor with Single Shear Coaxial Injector." In High Performance Computing in Science and Engineering '10, 203–15. Berlin, Heidelberg: Springer Berlin Heidelberg, 2011. http://dx.doi.org/10.1007/978-3-642-15748-6_16.
Conference papers on the topic "Simulations Euler-Lagrange":
1
Ma, Jingsen, Chao-Tsung Hsiao, and Georges L. Chahine. "Euler-Lagrange Simulations of Bubble Cloud Dynamics Near a Wall." In ASME 2013 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/imece2013-65191.
Abstract:
We present in this paper a two-way coupled Eulerian-Lagrangian model to study the dynamics of microbubble clouds exposed to incoming pressure waves and the resulting pressure loads on a nearby rigid wall. The model simulates the two-phase medium as a continuum and solves the N-S equations using Eulerian grids with a time and space varying density. The microbubbles are modeled as interacting spherical bubbles, which follow a modified Rayleigh-Plesset-Keller-Herring equation and are tracked in a Lagrangian fashion. A two-way coupling between the Euler and Lagrange components is realized through the local mixture density associated with the bubbles volume change and motion. Using this numerical framework, simulations involving a large number of bubbles were conducted under driving pressures of different frequencies. The results show that the frequency of the driving pressure is critical in determining the overall dynamics: either a collective strongly coupled cluster behavior or non-synchronized weaker multiple bubble oscillations. The former creates extremely high pressures with peak values orders of magnitudes higher than that of the excitation pressures. This occurs when the driving frequency matches the natural frequency of the bubble cloud. The initial distance between the bubble cloud and the wall is also critical on the resulting pressure loads. A bubble cloud collapsing very close to the wall exhibits a cascading collapse with the bubbles farthest from the wall collapsing first and the nearest ones collapsing last, thus the energy accumulates and then results in very violent pressure peaks at the wall. Farther from the wall, the bubble cloud collapses quasi spherically with the cloud center collapsing last.
2
Cunha Caldeira Mesquita, Léo, Aymeric Vié, and Sébastien Ducruix. "Two-Phase Flow Large Eddy Simulations of a Staged Multipoint Swirling Burner: Comparison Between Euler-Euler and Euler-Lagrange Descriptions." In ASME Turbo Expo 2017: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/gt2017-64489.
Abstract:
A two-staged swirling burner is numerically simulated through large eddy simulations. The impact of the liquid phase modeling approach is evaluated comparing the Eulerian and Lagrangian frameworks for two different operation points, full pilot injection and full multipoint injection. For the full multipoint injection, since the operation point is closer to a Lean Premixed Prevaporized (LPP) regime, both liquid phase models present similar flame structure (an M flame). For the full pilot injection, Eulerian and Lagrangian approaches result in different flames for equivalent boundary conditions: the Eulerian simulation produces a ‘tulip’ flame, while the Lagrangian spray forms a lifted flame. To assess the model sensitivity to boundary conditions parameters, complementary Lagrangian simulations are made varying injected droplets’ diameter and spray angle, this time resulting in a ‘tulip’ flame very similar to the Eulerian one. Finally, a last Eulerian simulation is made, where the injected droplets’ diameter is increased, still leading to a ‘tulip’ flame, showing that the strong interaction between liquid phase and flame highly impact the results.
3
Ma, Jingsen, Xiaolong Deng, Chao-Tsung Hsiao, and Georges L. Chahine. "Hybrid MPI-OpenMP Accelerated Euler-Lagrange Simulations of Microbubble Enhanced HIFU." In ASME 2021 Fluids Engineering Division Summer Meeting. American Society of Mechanical Engineers, 2021. http://dx.doi.org/10.1115/fedsm2021-65815.
Abstract:
Abstract Microbubble enhanced High Intensity Focused Ultrasound (HIFU) is of great interest to tissue ablation for solid tumor treatments such as in liver and brain cancers, in which contrast agents/microbubbles are injected into the targeted region to promote heating and reduce pre-focal tissue damage. A compressible Euler-Lagrange coupled model has been developed to accurately characterize the acoustic and thermal fields during this process. This employs a compressible Navier-Stokes solver for the ultrasound acoustic field and a discrete singularities model for bubble dynamics. To address the demanding computational cost in practical biological applications, a multi-level hybrid MPI-OpenMP parallelization scheme is developed to take advantage of both scalability of MPI and load balancing of OpenMP. At the first level, the Eulerian computational domain is divided into multiple subdomains and the bubbles are subdivided in groups based on which subdomain they fall into. At the next level, in each subdomain containing bubbles, multiple OpenMP threads are activated to speed up the bubble computations. More OpenMP threads are used inside each subdomain where the bubbles are clustered. By doing this, MPI load imbalance issue due to non-uniformity of bubble presence is compensated. The hybrid MPI-OpenMP Euler-Lagrange solver is used to conduct simulations and physical studies of bubble-enhanced HIFU problems containing a large number of microbubbles. The phenomenon of acoustic shadowing caused by the bubble cloud is then analyzed and discussed. Hybrid parallelization efficiency tests and demonstration of its advantages against using MPI alone are presented.
4
Feng, Yu, and Clement Kleinstreuer. "DDPM-DEM Simulations of Particulate Flows in Human Tracheobronchial Airways." In ASME 2013 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/imece2013-62307.
Abstract:
Dense particle-suspension flows in which particle-particle interactions are a dominant feature encompass a diverse range of industrial and geophysical contexts, e.g., slurry pipeline, fluidized beds, debris flows, sediment transport, etc. The one-way dispersed phase model (DPM), i.e., the conventional one-way coupling Euler-Lagrange method is not suitable for dense fluid-particle flows [1]. The reason is that such commercial CFD-software does not consider the contact between the fluid, particles and wall surfaces with respect to particle inertia and material properties. Hence, two-way coupling of the Dense Dispersed Phase Model (DDPM) combined with the Discrete Element Method (DEM) has been introduced into the commercial CFD software via in-house codes. As a result, more comprehensive and robust computational models based on the DDPM-DEM method have been developed, which can accurately predict the dynamics of dense particle suspensions. Focusing on the interaction forces between particles and the combination of discrete and continuum phases, inhaled aerosol transport and deposition in the idealized tracheobronchial airways [2] was simulated and analyzed, generating more physical insight. In addition, it allows for comparisons between different numerical methods, i.e., the classical one-way Euler-Lagrange method, two-way Euler-Lagrange method, EL-ER method [3], and the present DDPM-DEM method, considering micron- and nano-particle transport and deposition in human lungs.
5
Konan, N. A., S. Lai´n, O. Simonin, and M. Sommerfeld. "Comparison Between Euler-Euler and Euler-Lagrange Computations of Gas-Solid Turbulent Flow in a Horizontal Channel With Different Wall Roughness." In ASME 2006 2nd Joint U.S.-European Fluids Engineering Summer Meeting Collocated With the 14th International Conference on Nuclear Engineering. ASMEDC, 2006. http://dx.doi.org/10.1115/fedsm2006-98263.
Abstract:
This paper presents practical eulerian rough wall boundary conditions for particle mean velocity and fluctuating components. The model derives from a pdf approach and the Sommerfeld particle-wall rebound theory [1]. We have implemented these boundary conditions in 2D Euler/Euler code “Me´lodif” by neglecting the “shadow effect” [2] and assuming an half-gaussian distribution for wall-normal incident particle velocities. Lagrangian calculations in which the particle-wall collisions are treated following Sommerfeld [1], are carried out. Low and high roughness cases are simulated and both simulations results are compared with Sommerfeld experimental database.
6
Bode, Mathis, Tobias Falkenstein, Vincent Le Chenadec, Seongwon Kang, Heinz Pitsch, Toshiyuki Arima, and Hiroyoshi Taniguchi. "A New Euler/Lagrange Approach for Multiphase Simulations of a Multi-Hole GDI Injector." In SAE 2015 World Congress & Exhibition. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 2015. http://dx.doi.org/10.4271/2015-01-0949.
7
Kopper, Patrick, Marcel Pfeiffer, Stephen Copplestone, and Andrea Beck. "An efficient halo approach for Euler-Lagrange simulations based on MPI-3 shared memory." In HPC Asia 2021: The International Conference on High Performance Computing in Asia-Pacific Region. New York, NY, USA: ACM, 2021. http://dx.doi.org/10.1145/3440722.3440904.
8
Hussain, Irfan, Mohammad I. Awad, Ali Bin Junaid, Federico Renda, Lakmal Seneviratne, and Dongming Gan. "Dynamic modeling and numerical simulations of a passive robotic walker using Euler-Lagrange method." In 2018 11th International Symposium on Mechatronics and its Applications (ISMA). IEEE, 2018. http://dx.doi.org/10.1109/isma.2018.8330124.
9
Bernard, Manuel, Anthony Wachs, and Eric Climent. "Multiscale Approach for Particulate Flows, Application to Fluidized Beds." In ASME 2014 4th Joint US-European Fluids Engineering Division Summer Meeting collocated with the ASME 2014 12th International Conference on Nanochannels, Microchannels, and Minichannels. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/fedsm2014-22020.
Abstract:
In this paper, a discrete element method (DEM) coupled with computational fluid dynamics (CFD) and a distributed Lagrange multiplier - fictitious domain method (DLM-FD) are used is order to model three-dimensional fluidized beds. Particle-particle and wall-particle contacts are handled thanks to a soft sphere model. For the DEM-CFD model, also called Euler-Lagrange model, fluid dynamics variables are locally averaged and solved on a grid larger than the particle size whereas for the DLM-FD grid cells are around 20 times smaller than the particle characteristic length. The aim of this work is to extract information from DLM-FD simulations to improve the correlations used in the DEM-CFD model. First, particles and fluid equations are presented for the Euler-Lagrange model. Then, fluid-particle interaction is detailed. Eventually, we present preliminary simulations and results with both models in a 3D fluidized bed configuration.
10
Ching, Eric J., and Matthias Ihme. "Smooth projection kernels for Euler-Lagrange simulations on arbitrary elements computed with discontinuous Galerkin schemes." In AIAA Scitech 2020 Forum. Reston, Virginia: American Institute of Aeronautics and Astronautics, 2020. http://dx.doi.org/10.2514/6.2020-1796.
Reports on the topic "Simulations Euler-Lagrange":
1
Steedman, David W. COUPLED EULER-LAGRANGE SIMULATION OF THE JOLT HE EVENT AND RELEVANCE TO THE SHOCK PHYSICS EXPERIMENTS. Office of Scientific and Technical Information (OSTI), May 2013. http://dx.doi.org/10.2172/1082230.