Application of a one-fluid model for large scale homogeneous unsteady cavitation: The modified Schmidt model

Xie, Wenfeng; Liu, T.G.; Khoo, Boo Cheong

doi:10.1016/j.compfluid.2005.05.006

Cited by 80 publications

(39 citation statements)

References 18 publications

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“…Cavitation is treated using a one-fluid model, where the cavitation is assumed to be homogeneous mixture of vapor and liquid. A number of studies have demonstrated that the one-fluid cavitation model is able to account for cavitation effects accurately and efficiently [16,18,32]. Applications of the one-fluid model to 2D and 3D problems are exactly the same as to 1D problems.…”

Section: Introductionmentioning

confidence: 75%

“…It is also found that the effect of cavitation collapse appears to be small in contrast to the first shock because the energy can be rapidly dissipated through the semi-infinite fluid domain. On the other hand, if the fluid domain is finite, such as the case of an UNDEX inside a steel cylinder, the effect (in terms of peak pressure and load duration) of the cavitation collapse can actually be comparable to the first shock caused by the explosion [32]. The effects of the initial shock and cavitation collapse also depend on the compressibility of the material.…”

Section: Discussionmentioning

confidence: 98%

“…B,A and γ l are constants and are set equal to 3.31 × 10 8 Pa, 10 5 Pa and 7.0, respectively. The one-fluid model has been shown to be efficient to capture unsteady cavitation [16,32]. If all flow phases are treated as compressible and the cavitation mixture is assumed to be homogeneous and isentropic, the isentropic one-fluid cavitation model can be expressed as [16] …”

Section: Eulerian Solver For Compressible Flowmentioning

confidence: 99%

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Dynamic response of deformable structures subjected to shock load and cavitation reload

et al. 2006

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The dynamic response of deformable structures subjected to shock load and cavitation reload has been simulated using a multiphase model, which consists of an interface capturing method and a one-fluid cavitation model. Fluid-structure interaction (FSI) is captured via a modified ghost fluid method (Liu et al. in J Comput Phys 190:651-681, 2003), where the structure is assumed to be a hydro-elasto-plastic material if subjected to a strong shock load. Bulk cavitation near the structural surface is captured using an isentropic model (Liu et al. in J Comput Phys 201:80-108, 2004). The integrated multiphase model is validated by comparing numerical predictions with 1D analytical solutions, and with numerical solutions calculated using the cavitation acoustic finite element (CAFÉ) method (Sprague and Geers in Shocks vib 7: [105][106][107][108][109][110][111][112][113][114][115][116][117][118][119][120][121][122] 2001). To assess the ability of the multiphase model for multi-dimensions, underwater explosions (UNDEX) near structures are computed. The importance of cavitation reloading and FSI is investigated. Comparisons of the predicted pressure time histories with different explosion center are shown, and the effect on the structure is discussed.

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Section: Introductionmentioning

confidence: 75%

Section: Discussionmentioning

confidence: 98%

Section: Eulerian Solver For Compressible Flowmentioning

confidence: 99%

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Dynamic response of deformable structures subjected to shock load and cavitation reload

et al. 2006

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“…The equation is then expressed in terms of the pressure in the new time step by using Equations (7), (8) and (12). Thus, the Equation (17) is reduced to the form f ( p) = 0, a nonlinear equation in pressure…”

Section: Computational Proceduresmentioning

confidence: 99%

An alternate approach for modelling of transient vaporous cavitation

Sumam

Thampi

Sajikumar

2009

Numerical Methods in Fluids

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SUMMARYSimulation of cavitating flow has been a thrust area of research for long period due to its practical and economic importance. The major hurdle in developing a numerical model for such flows is the difficulty in representing the quick phase changes, in general, and the alternate change of flow from single phase to two phase and back, in particular. In this case, instability due to sharp variation of flow characteristics also restricts the development of numerical models. The present study demonstrates the use of a relatively simple formulation for the analysis of flow characteristics in a quasi-rigid pipeline under abrupt phase changes due to cavitation. A popular scheme-MacCormack scheme-was used for developing a numerical solution for this problem. It uses the conservative form of the governing equations, viz. conservation of mass and momentum, the transport equation and the constitutive relationship. The model can handle variable properties of the water-vapour mixture, which is highly compressible. A newly introduced pressure under-relaxation method overcomes the numerical instability due to sharp variation of flow characteristics during phase change. The model could predict the instant of occurrence of vapour pressure, duration of persistence of vapour pressure and the rise of pressure due to vapour collapse to satisfactory levels with published data and experimental results.

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“…More recently, Xie et al [76] reported that the model developed by Schmidt et al [74] did not work consistently when applied to the simulation of unsteady To conclude with the barotropic modelling approach, Catania et al [81] applied and assessed a model based on the barotropic equation, which …”

Section: Barotropic Equation Approachmentioning

confidence: 99%

A CFD Study of Cavitation in Real Size Diesel Injectors

Patouna¹

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In Diesel engines, the internal flow characteristics in the fuel injection nozzles, such as the turbulence level and distribution, the cavitation pattern and the velocity profile affect significantly the air-fuel mixture in the spray and subsequently the combustion process. Since the possibility to observe experimentally and measure the flow inside real size Diesel injectors is very limited, Computational Fluid Dynamics (CFD) calculations are generally used to obtain the relevant information.The work presented within this thesis is focused on the study of cavitation in real size automotive injectors by using a commercial CFD code. It is divided in three major phases, each corresponding to a different complementary objective.The first objective of the current work is to assess the ability of the cavitation model included in the CFD code to predict cavitating flow conditions. For this, the model is validated for an injector-like study case defined in the literature, and for which experimental data is available in different operating conditions, RESUMENPara los motores Diesel, las características del flujo interno en las toberas de los inyectores, tales como el nivel y la distribución de la turbulencia, el nivel de cavitación y el perfil de velocidad, afectan de manera significativa a la mezcla de aire-combustible en los chorros y, por lo tanto, al proceso de la combustión. Puesto que la capacidad de observar experimentalmente y de medir el flujo en el interior de los inyectores Diesel de tamaño real es muy limitada, los cálculos CFD (dinámica de fluidos computacional) se utilizan generalmente para obtener la información relevante.El trabajo presentado en esta tesis está enfocado al estudio de la cavitación en inyectores reales de automoción, mediante un código comercial CFD.Está dividido en tres fases principales, cada una con un objetivo definido y complementario.El primer objetivo en este trabajo es evaluar la capacidad de predicción del modelo de cavitación integrado en el código CFD. Para ello, se valida el modelo para un caso de estudio académico bajo distintas condiciones de funcionamiento, con y sin cavitación, comparando con datos experimentales documentados en la bibliografía. En los estudios preliminares llevados a cabo, se prueban diferentes configuraciones numéricas referentes al modelo de cavitación y se estudia su influencia en la solución para determinar la configuración más adecuada. En general, se concluye que el modelo es capaz de predecir el inicio de la cavitación y su desarrollo. Los valores obtenidos de gasto másico y de flujo estrangulado muestran una coincidencia 12 satisfactoria con los resultados experimentales. Este estudio preliminar sirve de base para la comprensión física y numérica del problema.Posteriormente, y utilizando la configuración numérica más adecuada obtenida del estudio previo, se procede a realizar cálculos en condiciones no estacionarias para unos inyectores reales mono-orificio y multi-orificio, cada uno con dos tipos de tobera, cilíndrica y cónica. El objetiv...

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Application of a one-fluid model for large scale homogeneous unsteady cavitation: The modified Schmidt model

Cited by 80 publications

References 18 publications

Dynamic response of deformable structures subjected to shock load and cavitation reload

Dynamic response of deformable structures subjected to shock load and cavitation reload

An alternate approach for modelling of transient vaporous cavitation

A CFD Study of Cavitation in Real Size Diesel Injectors

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