A Level Set Immersed Boundary Method for Water Entry and Exit

Zhang, Yali

doi:10.4208/cicp.060709.060110a

Cited by 68 publications

(28 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Zhang et al [18] modelled both the entry and exit of a circular cylinder with constant velocity using their level-set immersed boundary method and a full NS solver. They too found good visual agreement with experiments for the free surface and comparable values for the slamming coefficients.…”

Section: Literaturementioning

confidence: 99%

RANS-VOF modelling of the Wavestar point absorber

et al. 2017

View full text Add to dashboard Cite

Numerical modelling has become commonplace in the development of offshore structures, however for dynamic systems such as Wave Energy Convertors (WECs) conventional numerical tools may not be able to capture the full range of behaviours required for engineering analysis. This is particularly problematic in extreme seas where the nonlinearities and coupled nature of these systems become important. In this work a fully nonlinear, coupled tool for simulation of WECs is produced and compare with physical measurements. Regular wave interactions with both a fixed and freely-pitching, 1:10 scale model of the Wavestar are reproduced numerically. The numerical model is shown to be capable of predicting the pressure on the float's surface and the fully coupled motion of the device. However, the results indicate that the higher-order free surface behaviour in the vicinity of the device is not being captured correctly. Finally, the numerical model is shown to cope with an extreme regular wave including large amplitude motion, full submersion and high levels of free surface distortion. The results presented suggest that the quality of the numerical reproduction does not decrease with wave steepness; however the execution time of simulations increases significantly with increased float oscillation.

show abstract

Section: Literaturementioning

confidence: 99%

RANS-VOF modelling of the Wavestar point absorber

et al. 2017

View full text Add to dashboard Cite

show abstract

“…Yan and Ma [39] introduced a QALE-FEM approach, based on a fully nonlinear potential theory, to deal with the interaction between waves and 2-D floating bodies. Zhang et al [41] developed a new level set immersed boundary method to simulate the interaction of free surface flow and the structure. They investigated cases like flow past a cylinder, water exit and entry of a cylinder and water entry of a falling wedge.…”

Section: Introductionmentioning

confidence: 99%

Simulation of 2D symmetry and asymmetry wedge water entry by smoothed particle hydrodynamics method

Farsi

Ghadimi

2014

J Braz. Soc. Mech. Sci. Eng.

View full text Add to dashboard Cite

This article presents a study of fluid-solid interaction in a free surface flow by smoothed particles hydrodynamics method. Different cases of symmetry and asymmetry wedge water entries are presented. All cases are performed at constant speed, considering the effect of gravity. First-order density filter, turbulence modeling and a pressure filter have been utilized. Through these compiling options, low-pass pressure filter has been able to eliminate the undesirable fluctuation of pressure, and good results have been achieved. Pressure distribution and free surface profiles have been produced in all cases. In the cases of symmetry wedge water entries, the obtained results were compared against the results of BEM, similarity and asymptotic solutions, but in the cases of asymmetry wedge water entry, the obtained results were compared against those of analytical work. Through these comparisons, it was found that although the general trend of the computed pressure distributions follows the results of the previous studies, there still exist some differences among them. Main difference between the obtained results and other studies is related to the position of the pressure peak. It was concluded that this may indeed be attributed to the nature of the applied methods and due to the methodology of cutting the edges in schemes like BEM to overcome the abrupt flow at the edge. Vertical force in particular symmetry and asymmetry cases was also computed and presented. It was found that the global behavior of the vertical force in both the symmetry and asymmetry wedge water entry is the same and that there are some differences among them in terms of decreasing rate as well as the maximum value of the force.

show abstract

“…Indeed, the entry of a hydrophobic object into water is known to form an air cavity behind it, whereas a non-coating (polished surface) object seems not to form it. A lot of studies on the water entry of a circular cylinder has been restricted to the twodimensional problem (see e.g., Cointe and Armand 1987;Oliver 2007;Wagner 1932 for analysis;Greenhow 1988;Lin and Shieh 1997;Zhu et al 2007 for experiment; Zhang et al 2010 for numerics). In the previous paper , we demonstrated experimentally that the rupture regime of the cavity behind the perfectly coated hydrophobic cylinder appeals for the spanwise three-dimensionality on the cavity film against the previous studies within 2D treatment.…”

Section: Introductionmentioning

confidence: 99%

Water entry of stripe-coated hydrophobic circular cylinders

Ueda

Iguchi

2011

J Vis

View full text Add to dashboard Cite

This paper visually demonstrates water entry of horizontal hydrophobic circular cylinders, 12 mm in diameter and 300 mm long, by three types of coating of a water-repellent material; (a) perfectly coated, (b) right half surface coated, and (c) stripe coated. After the entry of the cylinder into water, the hydrophobic surface of the cylinder forms an air cavity behind it, whereas the hydrophilic surface is perfectly wetted. As a result, the resulting cavities are found to independently grow and break off from the cylinder even for the Type (c).

show abstract

A Level Set Immersed Boundary Method for Water Entry and Exit

Cited by 68 publications

References 30 publications

RANS-VOF modelling of the Wavestar point absorber

RANS-VOF modelling of the Wavestar point absorber

Simulation of 2D symmetry and asymmetry wedge water entry by smoothed particle hydrodynamics method

Water entry of stripe-coated hydrophobic circular cylinders

Contact Info

Product

Resources

About