Numerical Simulation of Cavitation around a Two-Dimensional Hydrofoil using VOF Method and LES Turbulence Model

Roohi, Ehsan; Zahiri, Amirpooyan; Pasandidehfard, Mahmoud

doi:10.3850/978-981-07-2826-7_141

Cited by 13 publications

(14 citation statements)

References 23 publications

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“…Figure 2 compares the distribution of pressure coefficients over the hydrofoil surface with that of Roohi et al [40], and Figure 3 compares the normal directional distributions of x-velocity from hydrofoil surface with that of Huang et al [41]. As can be seen in those figures, there are good correlations between the three different approaches, as well as between the current results and the referred data.…”

Section: Verification Testssupporting

confidence: 62%

Numerical Investigation into Effects of Viscous Flux Vectors on Hydrofoil Cavitation Flow and Its Radiated Flow Noise

2018

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Abstract:In this study, cavitation flow around a hydrofoil and its radiated hydro-acoustic fields were numerically investigated, with an emphasis on the effects of viscous flux vectors. The full three-dimensional unsteady compressible Reynolds-averaged Navier-Stokes equations were numerically solved. The mass transfer model was adopted to model phase changes between liquid water and vapor. To resolve the numerical instability problem arising from the rapid changes in local density and speed of sound of the mixture, the preconditioning and dual-time stepping methods were employed. The filter-based turbulent model was applied to resolve the unstable cavitation flow field more accurately. In splitting the viscous terms, three approaches for dealing with viscous flux vectors were considered: the so-called viscous lagging, full viscous, and thin-layer models. Radiated hydro-acoustic waves were predicted by applying the Ffowcs Williams and Hawkings equations. The effects of the viscous flux vectors on the predicted flow fields and its radiated noise were then examined by comparing the hydro-dynamic forces, velocity distribution, volume fraction, far-field sound directivities, and sound spectrum of the three approaches. The results revealed that the thin-layer model can provide predictions as accurate as the full viscous model, but required less computational time.

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Section: Verification Testssupporting

confidence: 62%

Numerical Investigation into Effects of Viscous Flux Vectors on Hydrofoil Cavitation Flow and Its Radiated Flow Noise

2018

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“…Therefore, a systematic research on this topic is necessary. Recently, Large Eddy Simulation (LES) has been studied for unsteady cavitation simulations by a few researchers [35][36][37]. Some promising results have been obtained for some geometrically simplified cases.…”

Section: State Of the Artmentioning

confidence: 98%

Investigation of Cavitation Models for Steady and Unsteady Cavitating Flow Simulation

Tran¹,

Nennemann²,

Vu³

et al. 2015

International Journal of Fluid Machinery and Systems

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The objective of this paper is to evaluate the applicability of mass transfer cavitation models and determine appropriate numerical parameters for cavitating flow simulations. CFD simulations were performed for a NACA66 hydrofoil at cavitation numbers of 1.49 and 1.00, corresponding to steady sheet and unsteady sheet/cloud cavitating regimes using the Kubota and Merkle cavitation models. The Merkle model was implemented into CFX by User Fortran code. The Merkle cavitation model is found to give some improvements for cavitating flow simulation results for these cases. Turbulence modeling is also found to have an important contribution to the prediction quality of the simulations. The relationship between the turbulence viscosity modification, in order to take into account the local compressibility at the vapor/liquid interfaces, and the predicted numerical results is clarified. The limitations of current cavitating flow simulation techniques are discussed throughout the paper.

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“…LES, DES) seems to be promising. [5] [6] On the other hand LES or DES numerical computations have far greater demands on the quality and near wall refinement of the computational mesh.…”

Section: Cavitation Cloud Separationmentioning

confidence: 99%

Numerical simulation and experimental visualization of the separated cavitating boundary layer over NACA2412

Kozák

Rudolf

Sedlář³

et al. 2015

EPJ Web of Conferences

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Abstract. Cavitation is physical phenomenon of crucial impact on the operation range and service lifetime of the hydraulic machines (pumps, turbines, valves etc.). Experimental measurement of cavitation is expensive and time consuming process, while some important characteristic of the flow are difficult to measure due to the nature of the phenomenon. Current possibilities of computational fluid dynamics provide a way for deeper understanding of cavitation which is important for many applications in the hydraulic machines industry such as expanding operation range or extending lifetime of the hydraulic machines. Simplified model consists of NACA 2412 hydrofoil with 8 degrees angle of attack fixed in between the walls of cavitation tunnel. Present investigation focuses on comparison of vapor volume fractions obtained by 3D CFD simulations and high speed visualization of the real cavitation phenomena. Several operating regimes corresponding to different cavitation numbers are studied with aim to assess the dynamics of the separated cavitating sheets/clouds

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Numerical Simulation of Cavitation around a Two-Dimensional Hydrofoil using VOF Method and LES Turbulence Model

Cited by 13 publications

References 23 publications

Numerical Investigation into Effects of Viscous Flux Vectors on Hydrofoil Cavitation Flow and Its Radiated Flow Noise

Numerical Investigation into Effects of Viscous Flux Vectors on Hydrofoil Cavitation Flow and Its Radiated Flow Noise

Investigation of Cavitation Models for Steady and Unsteady Cavitating Flow Simulation

Numerical simulation and experimental visualization of the separated cavitating boundary layer over NACA2412

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