Numerical investigation of attached cavitation shedding dynamics around the Clark-Y hydrofoil with the FBDCM and an integral method

Long, Xinping; Cheng, Huaiyu; Wang, Xincheng; Arndt, Roger E. A.

doi:10.1016/j.oceaneng.2017.03.054

Cited by 65 publications

(13 citation statements)

References 66 publications

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“…where F c and F e are two empirical coefficients for the condensation and vaporization processes, and α nuc and R B respectively represent the volume fraction and the radius of the nucleation sites. These empirical constants in the ANSYS CFX (18.0 Version, ANSYS, Canonsburg, PA, USA) software [40] are set to F c = 0.01, F e = 50, α nuc = 5 × 10 −4 , and R B = 1 × 10 −6 m. The Zwart cavitation model has been widely used to simulate cavitating flows, and more descriptions about this popular numerical method can be found in [41][42][43][44]. Brief introductions of the simulation cases are listed in Table 1.…”

Section: Numerical Methods and Validationmentioning

confidence: 99%

Large Eddy Simulation of Turbulent Attached Cavitating Flows around Different Twisted Hydrofoils

Chen²,

Yang

et al. 2018

Energies

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In this paper, the turbulent attached cavitating flows around two different twisted hydrofoils, named as NACA0009 and Clark-y, are studied numerically, with emphasis on cavity shedding dynamic behavior and the turbulence flow structures. The computational method of large eddy simulation (LES) coupled with a homogeneous cavitation model is applied and assessed by previous experimental data. It was found that the predicted results were in good agreement with that of the experiment. The unsteady cavity morphology of the two hydrofoils undergoes a similar quasi-periodic process, but has different shedding dynamic behavior. The scale of the U-type shedding structures forming on the suction surface of NACA0009 is larger than that of Clark-y. This phenomenon is also present in the iso-surface distributions of Q-criterion. Otherwise, the time-averaged cavity morphology is dramatically different for the two hydrofoils, and it is found that the attached location of the cavity is closely related to the hydrofoil geometry. The time fluctuation of the lift force coefficients is affected significantly by the cavity shedding dynamics. Compared with NACA0009, the lift force of Clark-y shows more fluctuation, due to its complicated shedding behavior. Further analysis of the turbulent structure indicates that the more violent shedding behaviors can induce higher levels of turbulence velocity fluctuations.

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Section: Numerical Methods and Validationmentioning

confidence: 99%

Large Eddy Simulation of Turbulent Attached Cavitating Flows around Different Twisted Hydrofoils

Chen²,

Yang

et al. 2018

Energies

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“…For the momentum and turbulent quantities 2 nd order discretization was applied in each instance. Turbulence closure model sensitivity as those produced over hydrofoils, there is strong interaction between the eddy vortices formed and the generated vapor phase, creating strong pressure fluctuations [50][51][52] . These complex turbulent features present significant modelling challenges; In studying a cavitating venturi, Reboud et al 46 made the argument that the standard k- model tends to produce high turbulent viscosity ( t ) predictions in the separation region, which acts to dampen unsteady effects, leading to the prediction of a stable, fixed separation bubble.…”

Section: Numerics and Convergence Strategymentioning

confidence: 99%

Flow characteristics of vortex based cavitation devices

Simpson

Ranade

2019

AIChE Journal

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Vortex based hydrodynamic cavitation devices offer various advantages over conventional linear flow devices, such as early inception, low erosion risk and higher cavitational yield. Despite several promising applications, the key underlying flow characteristics are not yet adequately understood. This paper presents results of a computational investigation into cavitation in vortex devices. Multiphase computational fluid dynamics (CFD) results are presented and compared with experimental data on pressure drop over a range of flow rates. The results highlight the unique hydrodynamic characteristics of this type of device in relation to conventional linear flow reactors; cavitation inception occurs in the liquid bulk away from sold surfaces, and rapid pressure recovery rates are achieved. The models were used to simulate detailed time-pressure histories for individual vapour cavities, including turbulent fluctuations. The developed approach, models and results will provide a sound and useful basis for comprehensive multi-scale modelling of vortex-based devices for hydrodynamic cavitation.

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“…The Reynold-averaged Navier Stokes (RANS) equations are very popular in turbulent flow calculations because of their robustness and low computing power requirements. As RANS models were initially developed for incompressible single-phase fluids, many efforts have been made into the modification of the RANS model to expand their capabilities into unsteady cavitation simulations (Hong et al, 2015;Huang et al, 2013a;Long et al, 2017). To account for the drastic density variations in cavitating flows, Coutier-Delgosha et al (2003) reduced the turbulent eddy viscosity using the density-corrected model (DCM), and Johansen et al (2004) modified the turbulent eddy viscosity with a filter-based model (FBM).…”

Section: Introductionmentioning

confidence: 99%

Numerical investigation of passive cavitation control using a slot on a three-dimensional hydrofoil

Liu

Yan

Wood

2019

HFF

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Purpose The purpose of this paper is to study the mechanism and suppression of instabilities induced by cavitating flow around a three-dimensional hydrofoil with a particular focus on cavitation control with a slot. Design/methodology/approach The transient cavitating flow around a Clark-Y hydrofoil was investigated using a transport-equation-based cavitation model and the stress-blended eddy simulation model was used to capture the flow turbulence. A homogeneous Rayleigh–Plesset cavitation model was used to model the transient cavitation process and the results were validated with test data. A slot was applied to the hydrofoil to suppress cavitation instabilities, and various slot widths and exit locations were applied to the blade and the cavitation behavior, as well as drag/lift forces, were simulated and compared to investigate the effects of slot geometries on cavitation suppression. Findings The large eddy simulation based turbulence model was able to capture the interactions between the cavitation and turbulence. Moreover, the simulation revealed that the re-entrant jet was responsible for the periodic shedding of cavities. The results indicated that a slot was able to mitigate or even suppress cavitation-induced instabilities. A jet flow was generated at the slot exit and disturbed the re-entrant jet. If the slot geometry was properly designed, the jet could block the re-entrant jet and suppress the unsteady cavitation behavior. Originality/value This study provides unique insights into the complicated transient cavitation flows around a three-dimensional hydrofoil and introduces an effective passive cavitation control technique useful to researchers and engineers in the areas of fluid dynamics and turbomachinery.

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Numerical investigation of attached cavitation shedding dynamics around the Clark-Y hydrofoil with the FBDCM and an integral method

Cited by 65 publications

References 66 publications

Large Eddy Simulation of Turbulent Attached Cavitating Flows around Different Twisted Hydrofoils

Large Eddy Simulation of Turbulent Attached Cavitating Flows around Different Twisted Hydrofoils

Flow characteristics of vortex based cavitation devices

Numerical investigation of passive cavitation control using a slot on a three-dimensional hydrofoil

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