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Characterization of Fluid Structure Interaction mechanisms and its application to vibroacoustic phenomenaQuintero Igeño, Pedro Manuel 15 October 2019 (has links)
[ES] La Interacción Fluido Estructura consiste en un problema físico en el
que dos materiales, gobernados por conjuntos de ecuaciones distintas, se
acoplan de diferentes formas.
La investigación en el campo de la Interacción Fluido Esructura
experimentó un importante desarrollo desde principios del siglo XX, de la
mano del campo de la aeroelasticdad. Durante el desarrollo de la industria
aeroespacial en el contexto de las guerras mundiales, el uso de materiales
más ligeros (y flexibles) comenzó a hacerse obligatorio para la obtención de
aeronaves con un comportamiento (y costes) aceptable.
A lo largo de los últimos años, el uso de materiales de construcción
cada vez más ligeros, se ha extendido al resto de campos de la industria.
A modo de ejemplo, podría servir el desarrollo de trackers en la producción
de energia solar; la utilización de materiales ligeros en ingeniería
civil o el desarrollo de elementos constructivos de plástico en la industria
del automóvil. Como consecuencia, la predicción con exactitud de las
deformaciones inducidas por un fluido y, si aplica, la influencia de estas
deformaciones en el propio flujo, ha adquirido una importancia vital.
Este documento intenta porporcionar, en primer lugar, una profunda
revisión de los métodos experimentales y computacionales que se han utilizado
en este contexto en la bibliografía, así como los análisis en problemas
de este tipo realizados por otros investigadores de cara a presentar una
primera aproximación a la Interacción Fluido Estructura.
Se verá cómo existe una importante cantidad de herramientas y
metodologías aplicables a cualquier tipo de problema y para cualquier
combinación de flujos y estructuras. Sin embargo, no existe una aproximación
general que, en función de valores de números adimensionales,
permita establecer cuáles de ellos son los de mayor importancia en este
tipo de problemas. En este sentido, se llevará a cabo un completo análisis
paramétrico durante el desarrollo del Capítulo 2 para establecer cuáles de
ellos son de mayor importancia.
Una vez se establezca la importancia de estos parámetros, se analizará
un caso que es de especial interés en la industria: la aerovibroacústica. Éste
es un caso particular de Interacción Fluido Estructura en el que, debido a
la combinación de parámetros adimensionales, la interacción se puede considerar
como prácticamente unidireccional, permitiendo extender estudios
mediante un conste computacional relativamente acotado. La Aerovibroacústica
y la vibroacústica se analizarán mediante la presentación de
dos casos de referencia, permitiendo proponer una metodología que se
podrá extender a otros problemas similares. / [CAT] La Interacció Fluid Estructura consisteix en un problema físic en què
dos materials, governats per conjunts d'equacions diferents, s'acoblen de
diferents formes.
La investigació en el camp de la Interacció Fluid Esructura va experimentar
un important desenvolupament des de principis del segle XX,
de la mà del camp de la aeroelasticdad. Durant el desenvolupament de
la indústria aeroespacial en el context de les guerres mundials, l'ús de
materials més lleugers (i flexibles) va començar a fer-se obligatori per a
l'obtenció d'aeronaus amb un comportament (i costos) acceptable.
Al llarg dels últims anys, l'ús de materials de construcció cada vegada
més lleugers, s'ha estès a la resta de camps de la indústria. A tall
d'exemple, podria servir el desenvolupament de textit trackers en la producció
d'energia solar; la utilització de materials lleugers en enginyeria
civil, el desenvolupament d'elements constructius de plàstic a la indústria
de l'automòbil. Com a conseqüència, la predicció amb exactitud de les
deformacions induïdes per un fluid i, si escau, la influència d'aquestes
deformacions en el propi flux, ha adquirit una importància vital.
Aquest document intenta porporcionar, en primer lloc, una profunda
revisió dels mètodes experimentals i computacionals que s'han utilitzat
en aquest context en la bibliografia, així com les anàlisis en problemes
d'aquest tipus realitzats per altres investigadors de cara a presentar una
primera aproximació a la Interacció Fluid Estructura.
Es veurà com, encara que existeix una important quantitat d'eines
i metodologies aplicables a qualsevol tipus de problema i per a qualsevol
combinació de fluxos i estructures, no hi ha una aproximació general que,
en funció de valors de nombres adimensionals, permeti establir quins
d'ells són els de major importància en aquest tipus de problemes. En
aquest sentit, es durà a terme una completa anàlisi paramètric durant
el desenvolupament del Capítol 2 per a establir quins d'ells són de major
importància.
Un cop s'estableixi la importància d'aquests paràmetres, s'analitzarà
un cas que és d'especial interès en la indústria: la aerovibroacústica. Això
és un cas particular d'Interacció Fluid Estructura en què, a causa de la
combinació de paràmetres adimensionals, la interacció es pot considerar
com pràcticament unidireccional, permetent estendre estudis mitjançant
un consti computacional relativament acotat. La Aerovibroacústica i la
vibroacústica s'analitzaran mitjançant la presentació de dos casos de referència,
permetent proposar una metodologia que es podrà estendre a altres
problemes similars. / [EN] Fluid Structure Interaction is a physical problem where two different
materials, governed by different set of fundamental equation, are coupled
on different ways.
The research on the field of Fluid Structure Interaction experienced
a noticeable growth since the beginnings of the XXth century, by means
of the field of aeroelasticity. During the development of the aerospace
industry in the context of first and second Wolrd War, as the use of lighter
(and softer) materials became mandatory for the correct behavior (and cost
savings) of the produced aircrafts.
During these past years, the use of use of increasingly lighter construction
materials has extended to the rest of fields of the industry. As an
example, it could be mentioned the use of solar trackers on the solar energy
sector; the use of light materials on civil engineering or the use of plastic
for some constructive elements in the context of the automotive field. As a
consequence, the accurate prediction of the deformations induced to a fluid
flow over a structure and, if needed, the influence of this deformation on
the fluid flow itself is becoming of primal importance.
This document intends to provide with a deep review of the computational
and experimental reported methodologies already available on the
literature and the previous works performed by other researches in order
to infer a first approximation to the Fluid Structure Interaction Problem.
It will be observed how an important amount of solving methodologies
is available in order to face these problems regarding with the strength
of the interaction. However, a general approximation allowing to predict
this strength as a function of a set of dimensional number is rarely
known. In this sense, a full parametric study will be performed during the
development of Chapter 2 showing which of them are of higher importance.
Once the influence of these parameters is determined, a case of special
interest will be analyzed: aerovibroacoustics. This, is a particular case
of Fluid Structure Interaction where, due to the combination of its nondimensional
parameters, one directional coupling can be supposed for most
of the cases. Aerovibroacoustics and vibroacoustics will be analyzed by
means of two reference cases, allowing finally to propose a methodology
which could be extended for other related problems. / Quintero Igeño, PM. (2019). Characterization of Fluid Structure Interaction mechanisms and its application to vibroacoustic phenomena [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/128412 / TESIS
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Úprava parkovacích míst v areálu VUT FSI, Technická 2, Brno / Modification parking places in VUT FSI area, Technická 2, BrnoPazdera, Igor January 2009 (has links)
Diploma thesis is concerned with problems of parking places in VUT FSI area, Technická 2, Brno. In introduction there are explained methods of parking, sorting and orientation proportions of vehicles. Then there are explained basic requirements for parking areas according to valid norms and rules. In this task there is analyzed original and actual status of parking. Before separating suggestions is finished calculation of required number of parking places. Solution of whole problems around parking places is in three projects. Results are compared in conclusion.
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CFD Analysis of the Flow Around a Paraglider WingGennari, Caterina January 2023 (has links)
In this study, the characteristics of the flow around a paraglider wing were investigated through the use of Computational Fluid Dynamics (CFD) simulations by solving both Reynolds Averaged Navier-Stokes equations and Delayed Detached Eddy Simulations were employed. This allowed the observation of how the unique shape of the canopy of a paraglider can influence the behaviour of the flow and how aerodynamic hysteresis can manifest on this sort of wing. Furthermore, the interaction between the highly deformable structure of the paraglider and the flow was examined through a two-way, loosely coupled Fluid-Structure Interaction (FSI) analysis. The methodology for the FSI analysis was first validated by employing a simplified model of the canopy before the full paraglider wing was analysed. Two different structural meshes were tested, using membrane elements or shell elements, respectively. The membrane element mesh prompted a collapse of the structure, while the mesh presenting shell elements allowed for a successful completion of the analysis.
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Hur urban täthet och rymlighet hanteras i Hagastaden / How urban density and spaciousness are handled in HagastadenGustafson, Daniel January 2019 (has links)
Urban täthet är ett ideal som präglar dagens stadsplanering. Det framgår från styrdokument och andra handlingar samt de förtätningsprojekt, t.ex. Hagastaden i Stockholm, som är ett resultat av dessa. Denna uppsats syftar till att söka förståelse för hur urban täthet och rymlighet balanseras i just Hagastaden, samt hur Hagastaden liknar respektive skiljer sig från andra bebyggelseområden i detta avseende. En täthetsjämförelse utförs mellan Hagastaden och Norra Djurgårdsstaden, ett annat förtätningsprojekt i Stockholm, dels på områdesnivå och dels på kvartersnivå. På områdesnivå beräknas exploateringstal över ett helt detaljplaneområde. I Hagastaden väljs planområde DP1 och i Norra Djurgårdsstaden planområde etapp Västra. På kvartersnivå beräknas nettoexploateringstal, markutnyttjande (andel bebyggd mark) och rymlighetstal, enligt definitioner angivna av Rådberg et al (1996), för ett kvarter i respektive område. I Hagastaden väljs kvarter Cellen och i Norra Djurgårdsstaden kvarter Töfsingdalen. Dessa kvarter jämförs även med de huvudgrupper av svenska stadstyper som beskrivs av Rådberg et al. Hagastadens offentliga friytor, dvs park- och torgytor, analyseras utifrån riktlinjer från styrdokumentet Grönare Stockholm samt den s.k. Alviksmodellen. Resultatet av täthetsjämförelsen visar vidare att Hagastaden är avsevärt tätare än både Norra Djurgårdsstaden och huvudgrupperna av svenska stadstyper. Planområde DP1 i Hagastaden har ett områdesvist exploateringstal på 2,54, jämfört med 1,65 för etapp Västra i Norra Djurgårdsstaden. Vidare har kvarter Cellen i Hagastaden ett nettoexploateringstal på 4,20, jämfört med 2,57 för kvarter Töfsingdalen i Norra Djurgårdsstaden. Båda kvarter överstiger alla huvudgrupper av svenska stadstyper med avseende på nettoexploateringstal, men liknar mest huvudgruppen Storstadsmässiga kvarter. Skillnaden i nettoexploateringstal verkar därmed bero på skillnaden i hushöjd, där kvarter Cellen har en genomsnittlig hushöjd på 11,1 våningar och kvarter Töfsingdalen 7,1 våningar. Planområde DP1 i Hagastaden med 16,7 % offentlig friyta Alviksmodellens riktlinje på minst 15 % offentlig friyta. Planområdet uppnår dock inte riktlinjen på minst 10 m2 offentlig friyta per boende med en offentlig friytetillgång på endast 6 m2 per boende. Vidare möts riktlinjerna för en god park- och naturtillgång endast delvis. / Urban density is an ideal that characterizes today's urban planning in Sweden. This is evident from various general planning documents as well as the densification projects, e.g. Hagastaden in Stockholm, which are a result of these. This paper aims to find an understanding of how urban density and spaciousness are balanced in Hagastaden, and how Hagastaden resembles or differs from other development areas in this respect. Hagastaden and Norra Djurgårdsstaden, another densification project in Stockholm, are compared with respect to density, partly at an area level and partly at a block level. As for the area level, the floor space index (FSI) is calculated for an entire detailed development plan area. In Hagastaden’s plan area DP1 and in Norra Djurgårdsstaden plan area etapp Västra. As for the block level, the floor space index (Swedish: nettoexploateringstal), land use (Swedish: andel bebyggd mark) and spaciousness index (Swedish: rymlighetstal) are calculated, as defined by Rådberg et al (1996), for one block in each area. The block Cellen is chosen in Hagastaden and in Norra Djurgårdsstaden the block Töfsingdalen. These blocks are also compared with the main groups of Swedish city types as described by Rådberg et al. Hagastaden's public open spaces, i.e. park and square areas, are analyzed based on guidelines from the document Grönare Stockholm and the so called Alviksmodellen. The result of the density comparison shows that Hagastaden is considerably denser than both Norra Djurgårdsstaden and the main groups of Swedish city types. DP1 in Hagastaden has an area-wide floor space index of 2.54, compared to 1.65 for etapp Västra in Norra Djurgårdsstaden. Furthermore, the housing block Cellen in Hagastaden has a floor space index of 4.20, compared to 2.57 for Töfsingdalen in Norra Djurgårdsstaden. Both blocks exceed all main groups of Swedish city types with respect to floor space index, but most closely resemble the main group Big city blocks (Swedish: Storstadsmässiga kvarter). The difference in floor space index seems to be mainly due to the difference in number of floors, where the block Cellen has an average number of 11.1 floors and the block Töfsingdalen 7.1 floors. DP1 in Hagastaden, with a 16.7 % share of public open space, achieves the Alviksmodellen guideline of at least 15% public open space. However, it does not achieve the guideline of at least 10 m2 of public open space per resident with only 6 m2 per resident. Furthermore, the guidelines for good access to park and nature are only partly met.
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A Fluid Structure Interaction Model Of Intracoronary Atherosclerotic Plaque RuptureTeuma-Melago, Eric 01 January 2006 (has links)
Plaque rupture with superimposed thrombosis is the primary cause of acute coronary syndromes of unstable angina, myocardial infarction and sudden death. Although intensive studies in the past decade have shed light on the mechanism that causes unstable atheroma, none has directly addressed the clinical observation that most myocardial infarction (MI) patients have moderate stenoses (less than 50%). Considering the important role the arterial wall compliance and pulsitile blood flow play in atheroma rupture, fluid-structure interaction (FSI) phenomenon has been of interest in recent studies. In this thesis, the impact is investigated numerically of coupled blood flow and structural dynamics on coronary plaque rupture. The objective is to determine a unique index that can be used to characterize plaque rupture potential. The FSI index, developed in this study for the first time derives from the theory of buckling of thin-walled cylinder subjected to radial pressure. Several FSI indices are first defined by normalizing the predicted hemodynamic endothelial shear stress by the structural stresses, specifically, by the maximum principal stress (giving the ratio ), and the Von Mises stress (giving the ratio ). The predicted at the location of maximum (i.e { }) denoted , is then chosen to characterize plaque rupture through systematic investigation of a variety of plaque characteristics and simulated patient conditions. The conditions investigated include varying stenosis levels ranging from 20% to 70%, blood pressure drop ranging from 3125 Pa/m to 9375 Pa/m, fibrous cap thickness ranging from to , lipid pool location ranging from the leading to the trailing edge of plaque, lipid pool volume relative to stenosis volume ranging from 24% to 80%, Calcium volume relative to stenosis volume ranging from 24% to 80% and arterial remodeling. The predicted varies with the stenosis severity and indicates that the plaques investigated are prone to rupture at approximately 40-45% stenosis levels. It predicts that high pressure significantly lowers the threshold stenosis rate for plaque rupture. In addition, the plaque potential to rupture increases for relatively thin fibrous cap, lipid core located near the leading plaque shoulder, and dramatically for relative lipid pool volume above 60%. However, calcium deposit has marginal effect on plaque rupture. Overall, the predicted results are consistent with clinical observations, indicating that the has the potential to characterize plaque rupture when properly established. In the appendix, the unsteady flow in a collapsible tube model of a diseased artery is solved analytically. The novelty of our approach is that the set of governing equations is reduced to a single integro-differential equation in the transient state. The equation was solved using the finite difference method to obtain the pressure and compliant wall behavior. The analytical approach is less computer-intensive than solving the full set of governing equations. The predicted membrane deflection is quite large at low inlet velocity, suggesting possible approach to breakdown in equilibrium. As the transmural pressure increases with wall deflection, bulges appear at the ends of the membrane indicating critical stage of stability, consistent with previous studies. An increase in wall thickness reduces the wall deflection and ultimately results in its collapse. The collapse is due to breakdown in the balance of wall governing equation. An increase in internal pressure is required to maintain membrane stability.
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APPLICATIONS OF COMPUTATIONAL FLUID DYNAMICS IN THE INDUSTRYSyed Imran (17637327) 14 December 2023 (has links)
<p dir="ltr">Precise measurement of the flowrate is crucial for both process control and energy consumption evaluation. The main aim of this work is to develop a methodology to calibrate mechanical flowmeters, designed to measure high viscosity fluids, in water. In order to accomplish this, a series of computational fluid dynamics (CFD) analysis are carried out to determine how the motion of the mechanical component varies with different flow rates of water and high viscosity fluids. This data is recorded and analyzed to develop calibration curves that relate the motion of the mechanical component the flow rates. From the calibration curves, it can be determined the required water flow rate to achieve the equivalent motion of the mechanical component in a specified viscosity. This method provides an efficient and cost-effective calibration process because it eliminates the need for calibrating using heated engine oil to achieve the fluid viscosity of the flow meter is designed. Flowmeter sensitivity analysis was also performed and it was observed that the motion of the mechanical component curves converges as the size of the flowmeter increases suggesting that the effect of viscosity on flowmeter sensitivity decreases as the size of the flowmeter is increased, likely due to reduced resistance to flow and smaller pressure drops. </p><p dir="ltr">The Kanbara Reactor ladle is a commonly used method in the steelmaking industry for hot-metal desulfurization pre-treatment. The impeller's configuration is pivotal to the reactor's performance, yet its precise function remains partially understood. This study introduces a 3-dimensional Volume-of-Fluid (VOF) model integrated with the sliding mesh technique, investigating the influence of five different impeller speeds. After Validating the model through experimental data, this numerical model is applied to investigate the typical developmental phenomena and the consequences of impeller speed variations on fluid flow characteristics, interface profile, and vortex core depth. The findings reveal that the rotational impeller induces a double-recirculation flow pattern in the axial direction due to the centrifugal discharging flow. With increasing impeller rotation speed, the vortex core depth also rises, emphasizing the substantial impact of impeller speed on vortex core depth.</p>
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Development of Energy-Based Endpoints for diagnosis of Pulmonary Valve InsufficiencyDas, Ashish January 2013 (has links)
No description available.
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Fluid-Structure Interaction Simulations of a Flapping Wing Micro Air VehicleByrd, Alex W. 04 June 2014 (has links)
No description available.
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Fluid-Structure Interaction of a Variable Camber Compliant WingMiller, Samuel C. 27 May 2015 (has links)
No description available.
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Computational Fluid Dynamic Modeling of Aortic Blood FlowBrown, Suzie 23 December 2014 (has links)
<p>Computational fluid dynamic (CFD) models of aortic blood flow have developed over the past decade from rigid one dimensional models to three dimensional models that include wall flexibility. Although anatomically correct, these models have been significantly idealized as compared to their physiologic in vivo conditions. This thesis investigates the effect of addition of four dimensional MRI inlet flow, motion of the heart at the aortic inlet and addition of wall elasticity coupled with tissue backing support. Results show that the addition of MRI inlet data and aortic inlet motion of the heart significantly change flow in the aorta and should be included in future aortic CFD simulations.</p> / Master of Applied Science (MASc)
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