Relevant bibliographies by topics / Compressible and incompressible fluids

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  2. Dissertations / Theses
  3. Books
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Academic literature on the topic 'Compressible and incompressible fluids'

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Published: 5 June 2025
Last updated: 8 July 2025

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Journal articles on the topic "Compressible and incompressible fluids"

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Godin, Oleg A. "Finite-amplitude acoustic-gravity waves: exact solutions." Journal of Fluid Mechanics 767 (February 12, 2015): 52–64. http://dx.doi.org/10.1017/jfm.2015.40.

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AbstractWe consider strongly nonlinear waves in fluids in a uniform gravity field, and demonstrate that an incompressible wave motion, in which pressure remains constant in each fluid parcel, is supported by compressible fluids with free and rigid boundaries. We present exact analytic solutions of nonlinear hydrodynamics equations which describe the incompressible wave motion. The solutions provide an extension of the Gerstner wave in an incompressible fluid with a free boundary to waves in compressible three-dimensionally inhomogeneous moving fluids such as oceans and planetary atmospheres.
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BENDAHMANE, MOSTAFA, ZIAD KHALIL, and MAZEN SAAD. "CONVERGENCE OF A FINITE VOLUME SCHEME FOR GAS–WATER FLOW IN A MULTI-DIMENSIONAL POROUS MEDIUM." Mathematical Models and Methods in Applied Sciences 24, no. 01 (2013): 145–85. http://dx.doi.org/10.1142/s0218202513500498.

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This paper deals with construction and convergence analysis of a finite volume scheme for compressible/incompressible (gas–water) flows in porous media. The convergence properties of finite volume schemes or finite element scheme are only known for incompressible fluids. We present a new result of convergence in a two or three dimensional porous medium and under the only consideration that the density of gas depends on global pressure. In comparison with incompressible fluid, compressible fluids requires more powerful techniques; especially the discrete energy estimates are not standard.
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Zhu, Zeqi, Hongxia Li, Jianjun Fu, and Qian Sheng. "Approximation of a Class of Incompressible Third Grade Fluids Equations." Discrete Dynamics in Nature and Society 2015 (2015): 1–13. http://dx.doi.org/10.1155/2015/627584.

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This paper discusses the approximation of weak solutions for a class of incompressible third grade fluids equations. We first introduce a family of perturbed slightly compressible third grade fluids equations (depending on a positive parameterϵ) which approximate the incompressible equations asϵ→0+. Then we prove the existence and uniqueness of weak solutions for the slightly compressible equations and establish that the solutions of the slightly compressible equations converge to the solutions of the incompressible equations.
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Shen, Jie, Xiaofeng Yang, and Qi Wang. "Mass and Volume Conservation in Phase Field Models for Binary Fluids." Communications in Computational Physics 13, no. 4 (2013): 1045–65. http://dx.doi.org/10.4208/cicp.300711.160212a.

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AbstractThe commonly used incompressible phase field models for non-reactive, binary fluids, in which the Cahn-Hilliard equation is used for the transport of phase variables (volume fractions), conserve the total volume of each phase as well as the material volume, but do not conserve the mass of the fluid mixture when densities of two components are different. In this paper, we formulate the phase field theory for mixtures of two incompressible fluids, consistent with the quasi-compressible theory [28], to ensure conservation of mass and momentum for the fluid mixture in addition to conservation of volume for each fluid phase. In this formulation, the mass-average velocity is no longer divergence-free (solenoidal) when densities of two components in the mixture are not equal, making it a compressible model subject to an internal con-straint. In one formulation of the compressible models with internal constraints (model 2), energy dissipation can be clearly established. An efficient numerical method is then devised to enforce this compressible internal constraint. Numerical simulations in confined geometries for both compressible and the incompressible models are carried out using spatially high order spectral methods to contrast the model predictions. Numerical comparisons show that (a) predictions by the two models agree qualitatively in the situation where the interfacial mixing layer is thin; and (b) predictions differ significantly in binary fluid mixtures undergoing mixing with a large mixing zone. The numerical study delineates the limitation of the commonly used incompressible phase field model using volume fractions and thereby cautions its predictive value in simulating well-mixed binary fluids.
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Nasu, Shoichi, and Mutsuto Kawahara. "An Analysis of Compressible Viscous Flows Around a Body Using Finite Element Method." Advanced Materials Research 403-408 (November 2011): 461–65. http://dx.doi.org/10.4028/www.scientific.net/amr.403-408.461.

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The objective of this paper is an analysis of a body in a compressible viscous flow using the finite element method. Generally, when the fluid flow is analyzed, an incompressible viscous flow is often applied. However fluids have compressibility in actual phenomena. Therefore, the compressibility should be concerned in Computational Fluid Dynamics [CFD]. In this study, two kind of equation is applied to basic equations. One is compressible Navier-stokes equation, the other is incompressible Navier-stokes equation considering density variation. These analysis results of both equations are compared.
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Colombo, Rinaldo M., and Graziano Guerra. "BV Solutions to 1D isentropic Euler equations in the zero mach number limit." Journal of Hyperbolic Differential Equations 13, no. 04 (2016): 685–718. http://dx.doi.org/10.1142/s0219891616500181.

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Two compressible immiscible fluids in 1D and in the isentropic approximation are considered. The first fluid is surrounded and in contact with the second one. As the Mach number of the first fluid vanishes, we prove the rigorous convergence for the fully nonlinear compressible to incompressible limit of the coupled dynamics of the two fluids. A key role is played by a suitably refined wave front tracking algorithm, which yields precise [Formula: see text], [Formula: see text] and weak* convergence estimates, either uniform or explicitly dependent on the Mach number.
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PRUŠA, VÍT, and K. R. RAJAGOPAL. "ON MODELS FOR VISCOELASTIC MATERIALS THAT ARE MECHANICALLY INCOMPRESSIBLE AND THERMALLY COMPRESSIBLE OR EXPANSIBLE AND THEIR OBERBECK–BOUSSINESQ TYPE APPROXIMATIONS." Mathematical Models and Methods in Applied Sciences 23, no. 10 (2013): 1761–94. http://dx.doi.org/10.1142/s0218202513500516.

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Viscoelastic fluid like materials that are mechanically incompressible but are compressible or expansible with respect to thermal stimuli are of interest in various applications ranging from geophysics and polymer processing to glass manufacturing. Here we develop a thermodynamical framework for the modeling of such materials. First we illustrate the basic ideas in the simpler case of a viscous fluid, and after that we use the notion of natural configuration and the concept of the maximization of the entropy production, and we develop a model for a Maxwell type viscoelastic fluid that is mechanically incompressible and thermally expansible or compressible. An important approximation in fluid mechanics that is frequently used in modeling buoyancy driven flows is the Oberbeck–Boussinesq approximation. Originally, the approximation was used for studying the flows of viscous fluids in thin layers subject to a small temperature gradient. However, the approximation has been used almost without any justification even for flows of non-Newtonian fluids induced by strong temperature gradients in thick layers. Having a full system of the governing equations for a Maxwell type viscoelastic mechanically incompressible and thermally expansible or compressible fluid, we investigate the validity of the Oberbeck–Boussinesq type approximation for flows of this type of fluids. It turns out that the Oberbeck–Boussinesq type approximation is in general not a good approximation, in particular if one considers "high Rayleigh number" flows. This indicates that the Oberbeck–Boussinesq type approximation should not be used routinely for all buoyancy driven flows, and its validity should be thoroughly examined before it is used as a mathematical model.
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Caggio, Matteo. "Inviscid incompressible limit for compressible micro-polar fluids." Nonlinear Analysis 216 (March 2022): 112695. http://dx.doi.org/10.1016/j.na.2021.112695.

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Secchi, Paolo. "On the incompressible limit of inviscid compressible fluids." ANNALI DELL UNIVERSITA DI FERRARA 46, no. 1 (2000): 21–33. http://dx.doi.org/10.1007/bf02837288.

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Breit, Dominic, Eduard Feireisl, and Martina Hofmanová. "Incompressible Limit for Compressible Fluids with Stochastic Forcing." Archive for Rational Mechanics and Analysis 222, no. 2 (2016): 895–926. http://dx.doi.org/10.1007/s00205-016-1014-y.

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Dissertations / Theses on the topic "Compressible and incompressible fluids"

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Bocchi, Edoardo. "Compressible-incompressible transitions in fluid mechanics : waves-structures interaction and rotating fluids." Thesis, Bordeaux, 2019. http://www.theses.fr/2019BORD0279/document.

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Ce manuscrit porte sur les transitions compressible-incompressible dans les équations aux dérivées partielles de la mécanique des fluides. On s'intéresse à deux problèmes : les structures flottantes et les fluides en rotation. Dans le premier problème, l'introduction d'un objet flottant dans les vagues induit une contrainte sur le fluide et les équations gouvernant le mouvement acquièrent une structure compressible-incompressible. Dans le deuxième problème, le mouvement de fluides géophysiques compressibles est influencé par la rotation de la Terre. L'étude de la limite à rotation rapide montre que le champ vectoriel de vitesse tend vers une configuration horizontale et incompressible.Les structures flottantes constituent un exemple particulier d'interaction fluide-structure, où un solide partiellement immergé flotte à la surface du fluide. Ce problème mathématique modélise le mouvement de convertisseurs d'énergie marine. En particulier, on s'intéresse aux bouées pilonnantes, installées proche de la côte où les modèles asymptotiques en eaux peu profondes sont valables. On étudie les équations de Saint-Venant axisymétriques en dimension deux avec un objet flottant à murs verticaux se déplaçant seulement verticalement. Les hypothèses sur le solide permettent de supprimer le problème à bord libre associé avec la ligne de contact entre l'air, le fluide et le solide. Les équations pour le fluide dans le domaine extérieur au solide sont donc écrites comme un problème au bord quasi-linéaire hyperbolique. Celui-ci est couplé avec une EDO non-linéaire du second ordre qui est dérivée de l'équation de Newton pour le mouvement libre du solide. On montre le caractère bien posé localement en temps du système couplé lorsque que les données initiales satisfont des conditions de compatibilité afin de générer des solutions régulières.Ensuite on considère une configuration particulière: le retour à l'équilibre. Il s'agit de considérer un solide partiellement immergé dans un fluide initialement au repos et de le laisser retourner à sa position d'équilibre. Pour cela, on utilise un modèle hydrodynamique différent, où les équations sont linearisées dans le domaine extérieur, tandis que les effets non-linéaires sont considérés en dessous du solide. Le mouvement du solide est décrit par une équation intégro-différentielle non-linéaire du second ordre qui justifie rigoureusement l'équation de Cummins, utilisée par les ingénieurs pour les mouvements des objets flottants. L'équation que l'on dérive améliore l'approche linéaire de Cummins en tenant compte des effets non-linéaires. On montre l'existence et l'unicité globale de la solution pour des données petites en utilisant la conservation de l'énergie du système fluide-structure.Dans la deuxième partie du manuscrit, on étudie les fluides en rotation rapide. Ce problème mathématique modélise le mouvement des flots géophysiques à grandes échelles influencés par la rotation de la Terre. Le mouvement est aussi affecté par la gravité, ce qui donne lieu à une stratification de la densité dans les fluides compressibles. La rotation génère de l'anisotropie dans les flots visqueux et la viscosité turbulente verticale tend vers zéro dans la limite à rotation rapide. Notre interêt porte sur ce problème de limite singulière en tenant compte des effets gravitationnels et compressibles. On étudie les équations de Navier-Stokes-Coriolis anisotropes compressibles avec force gravitationnelle dans la bande infinie horizontale avec une condition au bord de non glissement. Celle-ci et la force de Coriolis donnent lieu à l'apparition des couches d'Ekman proche du bord. Dans ce travail on considère des données initiales bien préparées. On montre un résultat de stabilité des solutions faibles globales pour des lois de pression particulières. La dynamique limite est décrite par une équation quasi-géostrophique visqueuse en dimension deux avec un terme d'amortissement qui tient compte des couches limites<br>This manuscript deals with compressible-incompressible transitions arising in partial differential equations of fluid mechanics. We investigate two problems: floating structures and rotating fluids. In the first problem, the introduction of a floating object into water waves enforces a constraint on the fluid and the governing equations turn out to have a compressible-incompressible structure. In the second problem, the motion of geophysical compressible fluids is affected by the Earth's rotation and the study of the high rotation limit shows that the velocity vector field tends to be horizontal and with an incompressibility constraint.Floating structures are a particular example of fluid-structure interaction, in which a partially immersed solid is floating at the fluid surface. This mathematical problem models the motion of wave energy converters in sea water. In particular, we focus on heaving buoys, usually implemented in the near-shore zone, where the shallow water asymptotic models describe accurately the motion of waves. We study the two-dimensional nonlinear shallow water equations in the axisymmetric configuration in the presence of a floating object with vertical side-walls moving only vertically. The assumptions on the solid permit to avoid the free boundary problem associated with the moving contact line between the air, the water and the solid. Hence, in the domain exterior to the solid the fluid equations can be written as an hyperbolic quasilinear initial boundary value problem. This couples with a nonlinear second order ODE derived from Newton's law for the free solid motion. Local in time well-posedness of the coupled system is shown provided some compatibility conditions are satisfied by the initial data in order to generate smooth solutions.Afterwards, we address a particular configuration of this fluid-structure interaction: the return to equilibrium. It consists in releasing a partially immersed solid body into a fluid initially at rest and letting it evolve towards its equilibrium position. A different hydrodynamical model is used. In the exterior domain the equations are linearized but the nonlinear effects are taken into account under the solid. The equation for the solid motion becomes a nonlinear second order integro-differential equation which rigorously justifies the Cummins equation, assumed by engineers to govern the motion of floating objects. Moreover, the equation derived improves the linear approach of Cummins by taking into account the nonlinear effects. The global existence and uniqueness of the solution is shown for small data using the conservation of the energy of the fluid-structure system.In the second part of the manuscript, highly rotating fluids are studied. This mathematical problem models the motion of geophysical flows at large scales affected by the Earth's rotation, such as massive oceanic and atmospheric currents. The motion is also influenced by the gravity, which causes a stratification of the density in compressible fluids. The rotation generates anisotropy in viscous flows and the vertical turbulent viscosity tends to zero in the high rotation limit. Our interest lies in this singular limit problem taking into account gravitational and compressible effects. We study the compressible anisotropic Navier-Stokes-Coriolis equations with gravitational force in the horizontal infinite slab with no-slip boundary condition. Both this condition and the Coriolis force cause the apparition of Ekman layers near the boundary. They are taken into account in the analysis by adding corrector terms which decay in the interior of the domain. In this work well-prepared initial data are considered. A stability result of global weak solutions is shown for power-type pressure laws. The limit dynamics is described by a two-dimensional viscous quasi-geostrophic equation with a damping term that accounts for the boundary layers
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Pareja, Victor David. "IMPULSE FORMULATIONS OF THE EULER EQUATIONS FOR INCOMPRESSIBLE AND COMPRESSIBLE FLUIDS." Master's thesis, University of Central Florida, 2007. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3265.

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The purpose of this paper is to consider the impulse formulations of the Euler equations for incompressible and compressible fluids. Different gauges are considered. In particular, the Kuz'min gauge provides an interesting case as it allows the fluid impulse velocity to describe the evolution of material surface elements. This result affords interesting physical interpretations of the Kuz'min invariant. Some exact solutions in the impulse formulation are studied. Finally, generalizations to compressible fluids are considered as an extension of these results. The arrangement of the paper is as follows: in the first chapter we will give a brief explanation on the importance of the study of fluid impulse. In chapters two and three we will derive the Kuz'min, E & Liu, Maddocks & Pego and the Zero gauges for the evolution equation of the impulse density, as well as their properties. The first three of these gauges have been named after their authors. Chapter four will study two exact solutions in the impulse formulation. Physical interpretations are examined in chapter five. In chapter six, we will begin with the generalization to the compressible case for the Kuz'min gauge, based on Shivamoggi et al. (2007), and we will derive similar results for the remaining gauges. In Chapter seven we will examine physical interpretations for the compressible case.<br>M.S.<br>Department of Mathematics<br>Sciences<br>Mathematical Science MS
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Chinarak, Theerarak. "Development of a time-based mass flow controller for compressible and incompressible fluids." Thesis, University of Bristol, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.503923.

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In this thesis a new type of Mass Flow Controller (MFC) is designed, constructed and used. Whilst existing MFCs rely on either pressure loss or temperature rise measurements to estimate and control flows, this new device is based on measuring time, which is more easily and accurately monitored. The device adopts the 'bucket and stopwatch' method to deliver specific and constant masses at pre-set time intervals. By alerting the time intervals, the mass flow is precisely controlled.
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Yang, Zhiyan. "Numerical simulation of incompressible and compressible flow." Thesis, University of Sheffield, 1989. http://etheses.whiterose.ac.uk/3485/.

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This thesis describes the development of a numerical solution procedure which is valid for both incompressible flow and compressible flow at any Mach number. Most of the available numerical methods are for incompressible flow or compressible flow only and density is usually chosen as a main dependent variable by almost all the methods developed for compressible flow. This practice limits the range of the applicability of these methods since density changes can be very small when Mach number is low. Even for high Mach number flows the existing time-dependent methods may be inefficient and costly when only the finial steady-state is of concern. The presently developed numerical solution procedure, which is based on the SIMPLE algorithm, solves the steady-state form of the Navier-stokes equations, and pressure is chosen as a main dependent variable since the pressure changes are always relatively larger than the density changes. This choice makes it possible that the same set of variables can be used for both incompressible and compressible flows. It is believed that Reynolds stress models would give better performance in some cases such as recirculating flow, highly swirling flow and so on where the widely used two equation k-e model performs poorly. Hence, a comparative study of a Reynolds stress model and the k-e model has been undertaken to assess their performance in the case of highly swirling flows in vortex throttles. At the same time the relative performance of different wall treatments is also presented. It is generally accepted that no boundary conditions should be specified at the outflow boundary when the outflow is supersonic, and all the variables can be obtained by extrapolation. However, it has been found that this established principle on the outflow boundary conditions is misleading, and at least one variable should be specified at the outflow boundary. It is also shown that the central differencing scheme should be used for the pressure gradient no matter whether it is subsonic or supersonic flow.
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Baghaei, Masoud. "Research on fluidic oscillators under incompressible and compressible flow conditions." Doctoral thesis, Universitat Politècnica de Catalunya, 2020. http://hdl.handle.net/10803/669607.

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One of the main advantages of fluidic oscillators is that they do not have moving parts, which brings high reliability whenever being used in real applications. To use these devices in real applications, it is necessary to evaluate their performance, since each application requires a particular injected fluid momentum and frequency. In this PhD., the performance of a given fluidic oscillator is evaluated at different Reynolds numbers via a 3D-computational fluid dynamics (CFD) analysis under incompressible and compressible flow conditions. In the first stage, the net momentum applied to the incoming jet is compared with the dynamic maximum stagnation pressure in the mixing chamber, to the dynamic output mass flow, to the dynamic feedback channels mass flow, to the pressure acting to both feedback channels outlets, and to the mixing chamber inlet jet oscillation angle. A perfect correlation between these parameters is obtained, therefore indicating the oscillation is triggered by the pressure momentum term applied to the jet at the feedback channels outlets. The stagnation pressure fluctuations appearing at the mixing chamber inclined walls are responsible for the pressure momentum term acting at the feedback channels outlets, thus it is proved that the oscillations are pressure-driven. In the second stage, several performance parameters were numerically evaluated as a function of different internal modifications via using 3D-CFD simulations. The evaluation is based on studying the output mass flow frequency and amplitude whenever several internal geometry parameters are modified. The geometry modifications considered were the mixing chamber inlet and outlet widths, and the mixing chamber inlet and outlet wall inclination angles. The concept behind this is, to evaluate how much the fluidic oscillator internal dimensions affect the device's main characteristics, and to analyze which parts of the oscillator produce a higher impact on the fluidic oscillator output characteristics. For the different internal modifications, evaluated, special care is taken in studying the forces required to flip the jet. The entire study is performed for three different Reynolds numbers, 8711, 16034 and 32068. Among the conclusions reached it is to be highlighted that, for a given Reynolds number, modifying the internal shape affects the oscillation frequencies and amplitudes. Any oscillator internal modification generates a much relevant effect as Reynolds number increases. Under all conditions studied, it was observed that the fluidic oscillator is pressure-driven under incompressible flow conditions as discussed in the first and second stages. In the third stage, the feedback channel effect on the oscillator output mass flow frequency and amplitude under compressible flow conditions were evaluated. In order to bring light to this point, a set of three dimensional Direct Numerical Simulations under compressible flow conditions, are introduced in the present stage, four different feedback channel lengths and two inlet fluid velocities are considered. From the results obtained, it was observed that as the inlet velocity increases, the fluidic oscillator output mass flow frequency and amplitude increase. An increase of the feedback channel length decreases the output mass flow oscillating frequency. At high feedback channel lengths, the form of the main oscillation tends to disappear, the jet inside the mixing chamber simply actuates at high frequencies, for these cases, the mass flow and pressure signals are very scattered due to the pressure waves appearing on mixing chamber converging surfaces and both feedback channels at the same time. Once the FC length exceeds a certain threshold, the oscillation stops. Under compressible conditions, the oscillations are pressure-driven as previously stated for the incompressible cases. The forces due to the pressure are much stronger than the mass flow flowing along the feedback channels.<br>El principal avantatge dels oscil·ladors fluídics es que no te parts mòbils, i això fa que sigui més fiable en aplicacions reals. Per tal d'aplicar aquests oscil·ladors en un cas concret, es necessari avaluar el seu comportament, doncs cada cas concret necessita una freqüència i quantitat de moviment donades. En el present doctorat s'ha analitzat mitjançant 3D-CFD, una configuració de oscil·lador fluídic per diferents números de Reynolds, diferents geometries internes i considerant el fluid com incompressible i compressible. Inicialment, la quantitat de moviment aplicada al jet entrant a la cambra de barreja, es comparada amb la pressió d'estancament dinàmica a les parets convergents de la cambra de barreja, amb el cabal màssic dinàmic que surt del actuador, amb el cabal màssic dinàmic que passa per els canals de realimentació, amb la pressió dinàmica que hi ha a la sortida dels canals de realimentació i amb el angle de oscil·lació del jet a l'entrada de la cambra de barreja. Tots aquests paràmetres es va veure que estaven correlacionats i això indicava que el origen de les oscil·lacions del jet era únic i era la pressió d'estancament a les parets convergents de la cambra de barreja, provant que les oscil·lacions son dirigides per gradients de pressió. Posteriorment es va fer el mateix tipus de estudi però modificant la amplada i angle de inclinació a l'entrada de la cambra de barreja i també modificant la amplada i angle de inclinació de les parets de sortida de la cambra de barreja. Aquestes quatre modificacions de la geometria interna es van fer per tres números de Reynolds diferents, 8711, 16034 i 32068. Entre les conclusions obtingudes cal destacar que, la freqüència i amplitud de oscil·lació del jet a la sortida del actuador pot ser modificada al variar les dimensions i angles interns de la cambra de barreja. Independentment del número de Reynolds estudiat i de la modificació interna considerada, es va comprovar que les oscil·lacions estaven dirigides per els gradients de pressió existents entre les dos sortides dels conductes de realimentació. L'efecte generat per qualsevol modificació interna era sempre més rellevant a números de Reynolds alts. En la tercera fase de la tesi el fluid es va considerar com a compressible subsònic, i es va avaluar els efectes de la modificació de la longitud dels canals de realimentació, sobre la freqüència i amplitud del flux que surt del oscil·lador. Quatre diferents longituds i dos números de Mach van ser avaluats. Al augmentar la longitud del canal de realimentació, la freqüència i amplitud de la oscil·lació disminueix, la oscil·lació tendeix a ser mes caòtica, apareixen altes freqüències que fan que el jet fluctuï en lloc de oscil·lar, de fet a partir de una certa longitud les oscil·lacions desapareixen i només hi han fluctuacions. Aquestes fluctuacions apareixen abans per elevats números de Mach. Les oscil·lacions son degudes a gradients de pressió, al igual que en el cas de fluid incompressible. De fet, per fluid compressible, el cabal màssic que passa per els canals de realimentació, juga un paper menys rellevant que en el cas de fluid incompressible.
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Courtin, Victor. "Extensions of some approximate Riemann Solvers for the computation of mixed incompressible-compressible flows." Electronic Thesis or Diss., université Paris-Saclay, 2024. http://www.theses.fr/2024UPASM041.

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Dans cette thèse, on s'intéresse à la simulation d'écoulements compressibles à l'aide de méthodes numériques implicites de type solveurs de Riemann, telles que la méthode de Roe ou le schéma HLLC. L'objectif est de développer des extensions faible nombre de Mach afin de préserver la précision des solutions discrètes dans la limite bas Mach. Ce type d'écoulement est souvent rencontré dans la simulation de configurations industrielles, caractérisées par la présence de zones plus ou moins étendues à faible vitesse.On se focalise sur la composante hyperbolique des équations de Navier-Stokes, qui constitue le cœur du problème d'analyse numérique abordé dans cette thèse, les équations d'Euler. On y expose une analyse approfondie et détaillée retraçant un sujet de recherche vieux de plusieurs décennies, qui présente encore d'importants défis, même pour ce modèle académique. La littérature recense un grand nombre d'extensions possibles pour le schéma de Roe, qui sont généralement faciles à implémenter. Ces extensions consistent à modifier certains termes de la dissipation numérique, en amplifiant ou diminuant leur contribution dans la limite faible nombre de Mach (on parle de « rescaling » de la dissipation numérique). Elles permettent par ailleurs d'obtenir une solution discrète compressible approchant la solution analytique issue de la théorie du potentiel pour le problème incompressible, sans pour autant introduire une détérioration des résultats dans le régime compressible. La capture des ondes de choc pour les écoulements transsoniques et supersoniques reste quasiment inchangée. Cependant, il existe plusieurs études suggérant de faire preuve de vigilance quant au choix de la formulation de ce type de correction. Il est connu de la littérature que des pertes de stabilité numérique sont généralement observées, ainsi que des risques d'apparition de problèmes de découplage vitesse-pression, détériorant fortement la précision globale de la solution discrète dans les faibles vitesses.Ces travaux se fondent sur deux corrections très différentes du schéma de Roe, issues de la littérature scientifique, et qui présentent des propriétés discrètes distinctes. La première approche, proposée par C.-C. Rossow, amplifie les sauts de pression en introduisant une vitesse artificielle du son, tandis que la seconde, développée par F. Rieper, vise à uniquement atténuer les sauts de vitesse. Ces deux approches illustrent deux stratégies majeures fréquemment utilisées dans les extensions à faible nombre de Mach. Nous commençons tout d'abord par l'analyse asymptotique discrète de l'approche proposée par C.-C. Rossow non publiée dans la littérature, en abordant également la formulation de la condition de stabilité au sens de von Neumann. On montre que cette correction évite l'écueil du découplage vitesse-pression. Ensuite, nous présentons une méthode numérique, visant à construire des phases implicites exactes nécessaires à l'intégration temporelle, en utilisant la différentiation algorithmique et un solveur direct. Ces techniques nous permettent de contourner la contrainte très stricte de stabilité sur le pas de temps, et d'obtenir des solutions discrètes en quelques centaines d'itérations, et ce même pour des écoulements à très faible nombre de Mach. La généralisation de ces travaux au schéma HLLC se fait ensuite en poursuivant l'analyse de la structure d'onde faite par M. Pelanti. Ces travaux révèlent une profonde similarité entre les dissipations numériques de ces méthodes. En particulier, nous dérivons un formalisme commun entre ces deux schémas, afin de simplifier les analyses, et la transposition d'une correction d'un solveur de Riemann approché à l'autre, au sens d'une relation très claire entre les deux méthodes. Cette analyse nous permet en particulier de dériver le schéma HLLC-Rossow, mais également d'expliciter l'expression de la matrice de viscosité du schéma HLLC, qui exhibe une ressemblance intéressante avec celle du schéma Roe<br>In this thesis, we focus on the simulation of compressible flows using implicit Godunov-type methods, such as the Roe method or the HLLC scheme. The objective is to develop low Mach number extensions that preserve the accuracy of discrete solutions in the low Mach number limit. This type of flow is frequently encountered in the simulation of industrial configurations, which are often characterized by the presence of more or less extensive low-speed areas.We focus on the hyperbolic component of the Navier-Stokes equations, which form the core of the numerical analysis problem addressed in this thesis, the Euler equations. We present an in-depth and detailed analysis of research topic that has been the subject of investigations for decades, and which continues to present significant challenges, even for this academic model. A review of the literature reveals a large number of possible extensions to the Roe scheme, which are generally easy to implement. These involve modifying specific terms of the numerical dissipation, either by amplifying or by diminishing their contribution in the low Mach number limit (also known as a rescaling of the numerical dissipation). They also enable us to obtain a discrete compressible solution that approaches the analytical solution derived from potential theory for the incompressible problem, without introducing any deterioration in the results in the compressible regime. The capture of shock waves for transonic and supersonic flows remains almost unaltered. However, there are a number of studies suggesting that care should be taken in the choice of formulation for this type of correction. It is well documented in the literature that losses in numerical stability are generally observed, as well as the risk of velocity-pressure decoupling problems appearing, which can significantly deteriorate the overall accuracy of the discrete solution for low-speed flows.This work is based on two very different corrections of the Roe scheme, taken from the scientific literature, and highlighting distinct discrete properties. The first approach, proposed by C.-C. Rossow, amplifies pressure jumps by introducing an artificial speed of sound, whereas the second approach, developed by F. Rieper, aims to attenuate velocity jumps exclusively. These two approaches illustrate two major strategies frequently used in low-Mach extensions. We begin with a discrete asymptotic analysis of the approach proposed by C.-C. Rossow, which has not been published in the literature, including the formulation of the von Neumann stability condition. It is demonstrated that this correction avoids the issue of pressure- velocity decoupling. Next, we present a numerical method for constructing the exact implicit phases required for time integration, using algorithmic differentiation and a direct solver. These techniques enable us to bypass the very strict stability constraint on the time step, thereby facilitating the acquisition of discrete solutions within a few hundred iterations, even for very low Mach number flows. The generalization of this work to the HLLC scheme is then made by continuing the wave structure analysis carried out by M. Pelanti. This work demonstrates a significant similarity between the numerical dissipations of these methods. In particular, a common formalism between these two schemes is derived, with the aim of simplifying the analyses, and transposing of a correction from one approximate Riemann solver to the other, in the sense of a very clear relationship between the two methods. In particular, this analysis enables us to derive the HLLC-Rossow scheme, but also to clarify the expression of the viscosity matrix of the HLLC scheme, which exhibits an interesting resemblance to that of the Roe scheme
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Choudhary, Aniruddha. "Verification of Compressible and Incompressible Computational Fluid Dynamics Codes and Residual-based Mesh Adaptation." Diss., Virginia Tech, 2015. http://hdl.handle.net/10919/51169.

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Code verification is the process of ensuring, to the degree possible, that there are no algorithm deficiencies and coding mistakes (bugs) in a scientific computing simulation. In this work, techniques are presented for performing code verification of boundary conditions commonly used in compressible and incompressible Computational Fluid Dynamics (CFD) codes. Using a compressible CFD code, this study assesses the subsonic inflow (isentropic and fixed-mass), subsonic outflow, supersonic outflow, no-slip wall (adiabatic and isothermal), and inviscid slip-wall. The use of simplified curved surfaces is proposed for easier generation of manufactured solutions during the verification of certain boundary conditions involving many constraints. To perform rigorous code verification, general grids with mixed cell types at the verified boundary are used. A novel approach is introduced to determine manufactured solutions for boundary condition verification when the velocity-field is constrained to be divergence-free during the simulation in an incompressible CFD code. Order of accuracy testing using the Method of Manufactured Solutions (MMS) is employed here for code verification of the major components of an open-source, multiphase flow code - MFIX. The presence of two-phase governing equations and a modified SIMPLE-based algorithm requiring divergence-free flows makes the selection of manufactured solutions more involved than for single-phase, compressible flows. Code verification is performed here on 2D and 3D, uniform and stretched meshes for incompressible, steady and unsteady, single-phase and two-phase flows using the two-fluid model of MFIX. In a CFD simulation, truncation error (TE) is the difference between the continuous governing equation and its discrete approximation. Since TE can be shown to be the local source term for the discretization error, TE is proposed as the criterion for determining which regions of the computational mesh should be refined/coarsened. For mesh modification, an error equidistribution strategy to perform r-refinement (i.e., mesh node relocation) is employed. This technique is applied to 1D and 2D inviscid flow problems where the exact (i.e., analytic) solution is available. For mesh adaptation based upon TE, about an order of magnitude improvement in discretization error levels is observed when compared with the uniform mesh.<br>Ph. D.
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Merle, Xavier. "Résolution des équations de stabilité globale en régimes incompressible et compressible avec une méthode aux différences finies de haute précision." Phd thesis, Paris, ENSAM, 2009. http://pastel.archives-ouvertes.fr/pastel-00005302.

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La plupart des écoulements en dynamique des fluides génèrent ou rencontrent des phénomènes instationnaires. Dans le domaine de l'aérospatial, au cours de la mise au point de certains moteurs de fusées d'altitude, des instationnarités basses fréquences ont été observées. Ces phénomènes, liés à l'interaction entre l'onde de choc et la couche limite turbulente qui se développe sur les parois, peuvent engendrer des déformations de la tuyère ou des mouvements inopportuns par rapport à son système d'attache. De nombreux travaux ont ´et´e entrepris afin d'en déterminer l'origine. L'´etude de la stabilité entre dans ce cadre. Dans ce contexte, le propos de cette thèse est de développer un code de stabilité globale adapté aux écoulements en régime compressible et en géométrie curviligne afin d'étudier la stabilité de l'interaction au sein de la tuyère. La résolution du problème est assuré par un schéma aux différences finies de type DRP. Le code est validé à travers plusieurs cas-tests incompressibles, compressibles et en maillage curviligne. Ces configurations permettent également de souligner les avantages du schéma de discrétisation retenu par rapport `a d'autres solutions plus classiques utilisées généralement dans ce type de problèmes.
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Martínez, Germán Andrés Gaviria. "Towards natural transition in compressible boundary layers." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/18/18148/tde-24052017-114027/.

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In this work, a DNS code was developed to investigate problems on transition in subsonic compressible boundary layer on a flat plate. Code validation tests were performed for linear and nonlinear stages of transition, on incompressible and compressible regimes. The focus of the present work is to investigate natural transition in subsonic boundary layers modeled by wave packets; and perform a preliminary study of transition induced by white noise. Three main problems were considered, namely, a DNS simulation and analysis of the ex- periment (MEDEIROS; GASTER, 1999b) of wave packet evolution on incompressible boundary layer, the influence of compressibility on wave packet evolution at subsonic Mach numbers and finally, a preliminary study of the evolution of a white noise perturbation in the boundary layer at Mach 0.2 and Mach 0.9. Comparisons between numerical and experimental results show remarkably good agreement in the linear and nonlinear stages, in both, spatial and Fourier spaces. A numerical simulation of this experiment and the analysis carried out is not available in the literature for wave packets in the incompressible boundary layer. The nonlinear modal analysis performed established the existence of tuned fundamental and subharmonic resonance of H-type and K-type in the packet. Influence of compressibility in the wave packet evolution was here investigated in boundary layers at Mach 0.7 and Mach 0.9. There are no works reported in the literature on wave packets in compressible subsonic boundary layer. In the linear regime, the oblique modes were the most unstable for Mach > 0.7, as expected by the results of the literature. In the nonlinear regime, strong streaks were observed, associated with low frequency modes that eventually decay downstream. An isolated wave packet at Mach 0.9 showed nonlinear amplification only in the subharmonic band, which may be associated to H-type or detuned resonance. However this packet has a relatively stable character. On the other hand, at Mach 0.9 spanwise interaction of wave packet pairs were more unstable than the isolated case, because stable modes for the isolated packet evolution becomes unstable in the wave packet interaction. This scenario evidenced the presence of oblique transition. Finally, the nonlinear evolution of the same white noise disturbance at Mach 0.2 and Mach 0.9 were observed to be completely different. In the incompressible boundary layer localized lambda vortex structures were observed, that could be associated to the local presence of H-type and/or K-type resonance. In the compressible regime, longitudinal vortex structures distributed across the entire domain seemed to be linked to oblique transition. In the white noise evolution, compressibility seems to have a stronger effect than in the wave packet evolution. In the conditions considered, the wave packet interaction appear to be a better representation of white noise compressible transition scenario.<br>No presente trabalho, um código DNS (Direct Numerical Simulation) foi desenvolvido para abordar problemas de transição para turbulência em camada limite subsônica compressível em uma placa plana. Foram realizados testes de validação de código , nos regimes linear e não linear do processo de transição, nos regimes incompressível e compressível. O foco do presente trabalho é estudar transição natural modelada por meio de pacotes de onda em camada limite compressível subsônica, e realizar uma análise preliminar da transição induzida por ruído branco. Três assuntos principais foram considerados: uma simulação DNS e uma análise comparativa com o experimento (MEDEIROS; GASTER, 1999b) sobre a evolução de um pacote de ondas em camada limite incompressível, a influência da compressibilidade na evolução de pacotes de ondas no regime subsônico, e por último, um estudo preliminar da transição induzida por ruído branco em Mach 0.2 e Mach 0.9. As comparações realizadas entre a solução numérica e os dados experimentais mostram uma boa concordância, nos regimes linear e não linear, tanto no espaço físico quanto no espaço de Fourier. A simulação numérica deste experimento e a análise realizada neste trabalho, não são encontradas na literatura para o regime incompressível. A análise modal não linear aplicada aos resultados, permitiu identificar a presença das ressonâncias tipo H e tipo K no pacote de ondas. A influência da compressibilidade na evolução dos pacotes de onda foi estudada em Mach 0.7 e Mach 0.9. Na literatura não há trabalhos sobre pacotes de ondas no regime sub- sônico. No regime linear da transição, os modos oblíquos resultam ser os mais instáveis para Mach > 0.7, como era de esperar, de acordo com os resultados da literatura. No regime não linear, foram observadas estrias de moderada amplitude, associadas com modos de baixa frequência que acabam decaindo. O pacote de ondas em Mach 0.9 apresentou amplificação não linear somente na banda subharmônica, que pode ser associada com transição tipo H ou ressonância dessintonizada. No entanto, o comportamento geral neste regime é estabilizante. Por sua vez, a interação entre pacotes de ondas em Mach 0.9 mostrou um comportamento desestabilizante, pois a interação acaba gerando amplificação não linear em modos que decaem no pacote isolado. Os modos amplificados sugerem a presença do mecanismo de transição oblíqua. Finalmente, a evolução da mesma perturbação constituída por ruído branco em Mach 0.2 e Mach 0.9, resultaram ser completamente diferentes. Na camada limite incompressível foram observados vórtices tipo lambda, que poderiam ser gerados pela presença localizada das ressonâncias tipo H e/ou tipo K. No regime compressível foram observados vórtices distribuidos em todo o domínio, o que sugere a presença da transição oblíqua. Na transição gerada por ruído branco a compressibilidade teve uma influência maior que no pacote de ondas. Nas condições estudadas, a interação entre pacotes de ondas parece ser uma melhor representação do ruído branco no regime compressível.
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Pontaza, Juan Pablo. "Least-squares variational principles and the finite element method: theory, formulations, and models for solid and fluid mechanics." Diss., Texas A&M University, 2003. http://hdl.handle.net/1969.1/288.

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We consider the application of least-squares variational principles and the finite element method to the numerical solution of boundary value problems arising in the fields of solidand fluidmechanics.For manyof these problems least-squares principles offer many theoretical and computational advantages in the implementation of the corresponding finite element model that are not present in the traditional weak form Galerkin finite element model.Most notably, the use of least-squares principles leads to a variational unconstrained minimization problem where stability conditions such as inf-sup conditions (typically arising in mixed methods using weak form Galerkin finite element formulations) never arise. In addition, the least-squares based finite elementmodelalways yields a discrete system ofequations witha symmetric positive definite coeffcientmatrix.These attributes, amongst manyothers highlightedand detailed in this work, allow the developmentofrobust andeffcient finite elementmodels for problems of practical importance. The research documented herein encompasses least-squares based formulations for incompressible and compressible viscous fluid flow, the bending of thin and thick plates, and for the analysis of shear-deformable shell structures.
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Books on the topic "Compressible and incompressible fluids"

1

Talwar, Mahesh. Multiphase, compressible, and incompressible flow. Gulf Pub. Co., Book Division, 1985.

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United States. National Aeronautics and Space Administration., ed. Compressible and incompressible fluid seals: Influence on rotordynamic response and stability. National Aeronautics and Space Administration, 1992.

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United States. National Aeronautics and Space Administration., ed. Compressible and incompressible fluid seals: Influence on rotordynamic response and stability. National Aeronautics and Space Administration, 1992.

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Institute for Computer Applications in Science and Engineering., ed. Preconditioned methods for solving the incompressible and low speed compressible equations. Institute for Computer Applications in Science and Engineering, NASA Langley Research Center, 1986.

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United States. National Aeronautics and Space Administration., ed. Studies of pressure-velocity coupling schemes for analysis of incompressible and compressible flows. National Aeronautics and Space Administration, 1987.

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N, Vatsa V., Radespiel R, and Institute for Computer Applications in Science and Engineering., eds. Preconditioning methods for low-speed flows. Institute for Computer Applications in Science and Engineering, NASA Langley Research Center, 1996.

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-H, Shih T., and United States. National Aeronautics and Space Administration., eds. An NPARC turbulence module with wall functions: Under cooperative agreement NCC3-370. National Aeronautics and Space Administration, 1997.

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United States. National Aeronautics and Space Administration., ed. PDF methods for combustion in high-speed turbulent flows: Second annual technical report. National Aeronautics and Space Administration, 1995.

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Pope, Stephen B. PDF methods for combustion in high-speed turbulent flows: Second annual technical report. National Aeronautics and Space Administration, 1995.

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Jen-Ping, Chen, and United States. National Aeronautics and Space Administration., eds. Computation of rotor-stator interaction using Navier-Stokes equations: Final report. CFD Lab, NSF Engineering Research Center for Computational Field Simulation, Mississippi State University, 1995.

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Book chapters on the topic "Compressible and incompressible fluids"

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Deville, Michel O. "Incompressible Newtonian Fluid Mechanics." In An Introduction to the Mechanics of Incompressible Fluids. Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-04683-4_1.

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AbstractThis chapter, presents the basic concepts of fluid mechanics such as velocity, acceleration, material derivative and the governing equations obtained from the conservation laws of mass, momentum, angular momentum and energy. The introduction of the constitutive relation for viscous incompressible Newtonian fluid leads to the Navier–Stokes equations. Boundary and initial conditions are discussed. Special attention is devoted to the meaning and differences between incompressible and compressible fluids. The Boussinesq equations are described. The chapter ends with considerations on the control volume method, a very efficient tool to solve fluid problems.
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Deville, Michel O. "Dimensional Analysis." In An Introduction to the Mechanics of Incompressible Fluids. Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-04683-4_2.

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AbstractDimensional analysis based on the principle of dimensional invariance allows the introduction of dimensionless numbers, like the famous Reynolds number, via the application of the Vaschy–Buckingham theorem. Dynamic similarity and self-similarity are described. The analysis of the dimensionless compressible Navier–Stokes equations shows how the incompressible equations are recovered when the Mach number goes to zero. The nature of pressure in the compressible and incompressible cases is broadly discussed.
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Weber, Hans Joachim. "Applied physics of compressible and incompressible fluids." In Critical Care Nephrology. Springer Netherlands, 1998. http://dx.doi.org/10.1007/978-94-011-5482-6_7.

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Masmoudi, Nader. "Asymptotic Problems and Compressible-Incompressible Limit." In Advances in Mathematical Fluid Mechanics. Springer Berlin Heidelberg, 2000. http://dx.doi.org/10.1007/978-3-642-57308-8_4.

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Santos, Lisa. "Variational Limit of Compressible to Incompressible Fluid." In Energy Methods in Continuum Mechanics. Springer Netherlands, 1996. http://dx.doi.org/10.1007/978-94-009-0337-1_11.

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Denner, Fabian, and Berend van Wachem. "A Unified Algorithm for Interfacial Flows with Incompressible and Compressible Fluids." In Advances in Fluid Mechanics. Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-1438-6_5.

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Wesseling, Pieter. "Unified methods for computing incompressible and compressible flow." In Principles of Computational Fluid Dynamics. Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-642-05146-3_14.

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Batu, Vedat. "Bernoulli and the Work-Energy Equations for Incompressible and Compressible Ideal Fluids." In Fluid Mechanics and Hydraulics. CRC Press, 2024. http://dx.doi.org/10.1201/9781003457442-13.

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Hafez, M. "On the Incompressible Limit of Compressible Fluid Flow." In Computational Fluid Dynamics for the 21st Century. Springer Berlin Heidelberg, 2001. http://dx.doi.org/10.1007/978-3-540-44959-1_16.

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Trakhinin, Yuri. "Existence and Stability of Compressible and Incompressible Current-Vortex Sheets." In Analysis and Simulation of Fluid Dynamics. Birkhäuser Basel, 2006. http://dx.doi.org/10.1007/978-3-7643-7742-7_13.

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Conference papers on the topic "Compressible and incompressible fluids"

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Basara, Branislav. "Basic Boundary Conditions for Incompressible and Compressible Flows Using Unstructured Meshes." In ASME/JSME 2003 4th Joint Fluids Summer Engineering Conference. ASMEDC, 2003. http://dx.doi.org/10.1115/fedsm2003-45534.

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The paper compiles the basic and frequently used boundary conditions in CFD calculations. Regardless of the type of boundary conditions, Dirichlet or Neumman, there are very important differences in the implementation procedure depending on the solved equations as well as on variables which are updated on the boundaries. Boundary conditions in the frame of the control volume method presented here, are adopted for the unstructured grids consisting of arbitrary polyhedral cells. There are no limitations on the employment of boundary conditions regarding mesh type. Some special treatments to improve results and the convergence rate are proposed. The emphasis is on the wall and the pressure boundaries.
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Cravero, C., A. Satta, and M. Marini. "Modelling of Incompressible Three-Dimensional Flow in Rotating Turbomachinery Passages." In ASME 2002 Joint U.S.-European Fluids Engineering Division Conference. ASMEDC, 2002. http://dx.doi.org/10.1115/fedsm2002-31177.

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A CFD method, previously developed by the authors for compressible flows, has been modified through a preconditioning technique to account for purely incompressible flows. Such a code is used to compute three-dimensional flows in a mixed flow pump impeller at design and off-design conditions. The results of the inviscid flow approach are critically discussed by comparison to available experimental data.
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Kajishima, Takeo, and Takashi Ohta. "LES and DNS of Turbulent Flows in Weakly Compressible Condition." In ASME/JSME 2007 5th Joint Fluids Engineering Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/fedsm2007-37300.

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Flow field of low Mach number (e.g. M &amp;lt;0.3) is usually simulated by the incompressible flow scheme due to the severe limitation of time-increment in the compressible flow scheme. In this work, we propose a modification to the usual incompressible scheme, based on the elliptic equation for pressure, to improve the accuracy for turbulent flows considering weak compressibility. Two examples will be shown to validate our method. (1) LES (Large-Eddy Simulation) was conducted for turbulent flow around NACA0012 airfoil. Particular attention was focused on the influence of compressibility, despite the low Mach number range. In addition, new subgrid scale model of one-equation type using dynamic procedure was compared with traditional Smagorinsky model. Our method successfully reproduced the separation bubble near the leading edge, resulted in the improvement in the intensity of pressure fluctuation. (2) DNS (Direct Numerical Simulation) of turbulent flow in a plane channel is carried out, taking wall temperature difference into account. As a result of the density fluctuation in near-wall eddies, asymmetric profiles are observed in turbulence statistics. By the 4-quadrant analysis of turbulent shear stress, it is found that the ejection events in the vicinity of the walls are particularly affected by the density variation.
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Rossow, Cord. "Toward Efficient Computation of Compressible and Incompressible Flows." In 36th AIAA Fluid Dynamics Conference and Exhibit. American Institute of Aeronautics and Astronautics, 2006. http://dx.doi.org/10.2514/6.2006-3522.

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Bodnár, T., and Ph Fraunié. "Numerical Evaluation of Mass-Diffusive Compressible Fluids Flows Models." In Topical Problems of Fluid Mechanics 2024. Institute of Thermomechanics of the Czech Academy of Sciences; CTU in Prague Faculty of Mech. Engineering Dept. Tech. Mathematics, 2024. http://dx.doi.org/10.14311/tpfm.2024.004.

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This contribution presents first numerical tests of some recently published alternative models for solution of viscous compressible and nearly incompressible models. All models are solved by high resolution compact finite difference scheme with strong stability preserving RungeKutta time stepping. The two simple but challenging computational test cases are presented, based on the double-periodic shear layer and the Kelvin-Helmholtz instability. The obtained time-dependent flow fields are showing pronounced shear and vorticity layers being resolved by the standard as well as by the new mass-diffusive modified models. The preliminary results show that the new models are viable alternative to the well established classical models.
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Timchenko, Victoria, John Reizes, and Eddie Leonardi. "Compressibility Effects in Micro Synthetic Jets." In ASME 2004 2nd International Conference on Microchannels and Minichannels. ASMEDC, 2004. http://dx.doi.org/10.1115/icmm2004-2345.

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Effects of including compressibility in the numerical modeling of flows produced by and in synthetic jet actuators — consisting of an oscillating diaphragm in a cavity with a small circular orifice in the face opposite the diaphragm — has been studied for axisymmetric configurations. Numerical results obtained on the assumption of incompressible and compressible flows with orifice diameters of the 20 and 40 μm and with an orifice length of 50 μm are compared. There are significant differences between compressible and incompressible flows for the 20 μm orifice, in that the jet velocity is greatly reduced when compressible flow is assumed, whereas the differences are much smaller in the 40 μm case. For both orifices the pressure rise upstream of the orifice is smaller when the fluid is compressible. It follows that results obtained on the assumption of incompressible flow cannot be extrapolated for micro-synthetic jet actuators handling compressible fluids.
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Rossow, C. C. "A flux splitting scheme for compressible and incompressible flows." In 14th Computational Fluid Dynamics Conference. American Institute of Aeronautics and Astronautics, 1999. http://dx.doi.org/10.2514/6.1999-3346.

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Balázsová, M., M. Feistauer, P. Sváček, and J. Horáček. "INCOMPRESSIBLE AND COMPRESSIBLE VISCOUS FLOW WITH LOW MACH NUMBERS." In Topical Problems of Fluid Mechanics 2017. Institute of Thermomechanics, AS CR, v.v.i., 2017. http://dx.doi.org/10.14311/tpfm.2017.002.

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McManus, K., and J. Magill. "Separation control in incompressible and compressible flows using pulsed jets." In Fluid Dynamics Conference. American Institute of Aeronautics and Astronautics, 1996. http://dx.doi.org/10.2514/6.1996-1948.

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Medic, G., M. Stanciu, B. Mohammadi, and S. Moreau. "Optimal airflow and blade design in compressible and incompressible flows." In 29th AIAA, Fluid Dynamics Conference. American Institute of Aeronautics and Astronautics, 1998. http://dx.doi.org/10.2514/6.1998-2898.

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Reports on the topic "Compressible and incompressible fluids"

1

Colella, Phillip. Oscillations and Concentrations in Compressible and Incompressible Fluids. Defense Technical Information Center, 1992. http://dx.doi.org/10.21236/ada254706.

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2

McHugh, P. R. An investigation of Newton-Krylov algorithms for solving incompressible and low Mach number compressible fluid flow and heat transfer problems using finite volume discretization. Office of Scientific and Technical Information (OSTI), 1995. http://dx.doi.org/10.2172/130602.

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3

Sturtevant, B. Rayleigh-Taylor instability in compressible fluids. Office of Scientific and Technical Information (OSTI), 1990. http://dx.doi.org/10.2172/6438368.

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4

Sturtevant, B. Rayleigh-Taylor instability in compressible fluids. Office of Scientific and Technical Information (OSTI), 1989. http://dx.doi.org/10.2172/5416500.

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5

McDonough, J. M., Y. Yang, and X. Zhong. Additive Turbulent Decomposition of the Incompressible and Compressible Navier-Stokes Equations. Defense Technical Information Center, 1993. http://dx.doi.org/10.21236/ada277321.

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6

Castillo, Victor Manuel. Cubic Spline Collocation Method for the Simulation of Turbulent Thermal Convection in Compressible Fluids. Office of Scientific and Technical Information (OSTI), 1999. http://dx.doi.org/10.2172/15014452.

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7

Sturtevant, B. Rayleigh-Taylor instability in compressible fluids: Final report for the period 1 October 1985-30 September 1986. Office of Scientific and Technical Information (OSTI), 1986. http://dx.doi.org/10.2172/6179982.

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8

Zhou, Yijie, Hyun-Kyung Lim, Valmor F. de Almeida, et al. Development of a Front Tracking Method for Two-Phase Micromixing of Incompressible Viscous Fluids with Interfacial Tension in Solvent Extraction. Office of Scientific and Technical Information (OSTI), 2012. http://dx.doi.org/10.2172/1081899.

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York, A. R. II. Development of modifications to the material point method for the simulation of thin membranes, compressible fluids, and their interactions. Office of Scientific and Technical Information (OSTI), 1997. http://dx.doi.org/10.2172/537397.

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