Experimental and numerical studies on the cavitation over flat hydrofoils with and without obstacle

Zhang, Lingxin; Ming, Chi; Deng, Jian; Shao, Xueming

doi:10.1007/s42241-019-0057-6

Cited by 12 publications

(5 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In addition, the microbubbles are considered rigid particles because the dimensionless number describing the shape of a microbubble shows < 1 in this paper. The obstacle line method [38,39] is used here to generate a turbulent boundary layer, as is often done in experiments [40]. Generally, a small-diameter obstacle line is placed along the leading edge The simulation parameters are determined as shown in Table 1, U ∞ is the inflow velocity, and U b is the velocity at which bubbles are injected into the flow field.…”

Section: Computational Domain and Boundary Conditionsmentioning

confidence: 99%

See 1 more Smart Citation

Large Eddy Simulation of Microbubble Drag Reduction in Fully Developed Turbulent Boundary Layers

Wang

Sun

et al. 2020

JMSE

View full text Add to dashboard Cite

Microbubble drag reduction has good application prospects. It operates by injecting a large number of bubbles with tiny diameters into a turbulent boundary layer. However, its mechanism is not yet fully understood. In this paper, the mechanisms of microbubble drag reduction in a fully developed turbulent boundary layer over a flat-plate is investigated using a two-way coupled Euler-Lagrange approach based on large eddy simulation. The results show good agreement with theoretical values in the velocity distribution and the distribution of fluctuation intensities. As the results show, the presence of bubbles reduces the frequency of bursts associated with the sweep events from 637.8 Hz to 611.2 Hz, indicating that the sweep events, namely the impacting of high-speed fluids on the wall surface, are suppressed and the streamwise velocity near the wall is decreased, hence reducing the velocity gradient at the wall and consequently lessening the skin friction. The suppression on burst frequency also, with the fluid fluctuation reduced in degree, decreases the intensity of vortices near the wall, leading to reduced production of turbulent kinetic energy.

show abstract

Section: Computational Domain and Boundary Conditionsmentioning

confidence: 99%

“…The obstacle line method [38,39] is used here to generate a turbulent boundary layer, as is often done in experiments [40]. Generally, a small-diameter obstacle line is placed along the leading edge of the flat-plate, and the fluid quickly transitions to turbulence after it flows through the obstacle line.…”

Section: Computational Domain and Boundary Conditionsmentioning

confidence: 99%

Large Eddy Simulation of Microbubble Drag Reduction in Fully Developed Turbulent Boundary Layers

Wang

Sun

et al. 2020

JMSE

View full text Add to dashboard Cite

show abstract

“…Jin [6] proposed one method that one single lateral wing was fixed at NACA0015 hydrofoil tail to suppress the separation of boundary layer flow; aim to control cavitation flow around NACA0015 hydrofoil was achieved. Zhang et al [7] placed the obstacle on the flat hydrofoil surface to control cavitation bubble shedding. They found that under the action of the obstacle, cavitation bubble length had significant reduction; on the other hand, bubble shedding pattern changed from the large scale to the small scale.…”

Section: Introductionmentioning

confidence: 99%

Numerical Investigation of Effects of Rectangular Structure on Cavitation Evolution Around NACA0015 Hydrofoil

Wang¹,

Zhao²,

Wang³

et al. 2022

Proceedings of the International Conference of Fluid Power and Mechatronic Control Engineering (ICFPMCE 2022)

View full text Add to dashboard Cite

A combination of an improved SST k-ω turbulence model with Zwart-Gerber-Belamri cavitation model was employed to perform the numerical simulation of cavitation flow around general NACA0015 hydrofoil and the hydrofoil with rectangular structure on the surface. Effects of the rectangular structure on cavitation evolution were determined. Cavitation bubble evolution process and distribution of streamlines were investigated. Results clearly indicated that average lift-drag ratio of the hydrofoil with rectangular structure on the surface increased by 15.98%. Cavitation bubbles decreased and the distribution scopes of vortices reduced significantly. Cavitation evolution was effectively suppressed.

show abstract

“…Li et al [22] analyzed the three dimensional large scale cavity structures around two hydrofoils and the typical unsteady dynamics characteristics with the modified shear stress transport model. Zhang [23] et al studied the effect of obstacles on the surface of hydrofoil on cavitation. The experimental and numerical results showed that small-scale cavitation shedding is the dominant factor of cavitation flow.…”

Section: Introductionmentioning

confidence: 99%

Comparative Study of Different Turbulence Models for Cavitational Flows around NACA0012 Hydrofoil

Zhao

Wan

Gao

2021

JMSE

View full text Add to dashboard Cite

The present work focuses on the comparison of the numerical simulation of sheet/cloud cavitation with the Reynolds Average Navier-Stokes and Large Eddy Simulation(RANS and LES) methods around NACA0012 hydrofoil in water flow. Three kinds of turbulence models—SST k-ω, modified SST k-ω, and Smagorinsky’s model—were used in this paper. The unstable sheet cavity and periodic shedding of the sheet/cloud cavitation were predicted, and the simulation results, namelycavitation shape, shedding frequency, and the lift and the drag coefficients of those three turbulence models, were analyzed and compared with each other. The numerical results above were basically in accordance with experimental ones. It was found that the modified SST k-ω and Smagorinsky turbulence models performed better in the aspects of cavitation shape, shedding frequency, and capturing the unsteady cavitation vortex cluster in the developing and shedding period of the cavitation at the cavitation number σ = 0.8. At a small angle of attack, the modified SST k-ω model was more accurate and practical than the other two models. However, at a large angle of attack, the Smagorinsky model of the LES method was able to give specific information in the cavitation flow field, which RANS method could not give. Further study showed that the vortex structure of the wing is the main cause of cavitation shedding.

show abstract

Experimental and numerical studies on the cavitation over flat hydrofoils with and without obstacle

Cited by 12 publications

References 18 publications

Large Eddy Simulation of Microbubble Drag Reduction in Fully Developed Turbulent Boundary Layers

Large Eddy Simulation of Microbubble Drag Reduction in Fully Developed Turbulent Boundary Layers

Numerical Investigation of Effects of Rectangular Structure on Cavitation Evolution Around NACA0015 Hydrofoil

Comparative Study of Different Turbulence Models for Cavitational Flows around NACA0012 Hydrofoil

Contact Info

Product

Resources

About