Analytical modelling for a three-dimensional hydrofoil with winglets operating beneath a free surface

a b s t r a c tThe present article presents a nonlinear analysis for determining the three-dimensional unsteady potentialflow characteristics about a wing subject to wing-in-ground effect (WIG) operating above progressive water waves. By means of the time-domain Green's function for the three-dimensional dipole moving above the free surface satisfying the dynamic and kinematic boundary conditions on the mean free surface, the influence of the free surface on the vortex ring is considered. Then, the nonlinear unsteady lifting surface theory is developed to study the lifting problem for a three-dimensional wing operating above progressive water waves. Furthermore, the roll-up shed from the wing in the presence of a free surface and water waves is taken into account. With the computed results, the non-dimensional force coefficients (including the lift coefficient, induced drag coefficient and lift-to-drag ratio) are presented with the variation of different geometry and water wave parameters. The data reported in the literature are presented to validate the present approach.Crown

show abstract

“…15. Comparison of the results by the present method with experimental data [ 26 ] and the lifting line theory [ 7 ].…”

Section: Green's Function For the Vortex Ring Without Incoming Wavementioning

confidence: 91%

“…In the previous study, the perturbed velocity components induced by the vortex filament are utilized to handle the steady freesurface boundary conditions [ 26 ]. However, the unsteady free-surface boundary condition contains the derivative of the velocity potential with respect to time.…”

Section: Green's Function For the Vortex Ring Without Incoming Wavementioning

confidence: 99%

Nonlinear lifting theory for unsteady WIG in proximity to incident water waves. Part 2: Three-dimension

Liang

Zong

Zou

2013

Applied Ocean Research

View full text Add to dashboard Cite

show abstract

“…The predictions from the proposed method are shown to be in favourable agreement with experimental measurements [22,23]. For other numerical simulation methods on the lifting body problem, one may refer to [24,25,26,27]. For the ship wave problem based on the free-surface Green function, a series of investigations on numerical implementation of the Neumann-Michell theory have been obtained by Noblesse and his co-workers.…”

Section: Introductionmentioning

confidence: 95%

“…To facilitate the understanding of the wave expansion, we employ (26) to derive the single source wave χ s expressible as…”

Section: Numerical Simulation For Free-surface Wavesmentioning

confidence: 99%

Straightforward discretisation of Green function and free-surface potential flow around a three-dimensional lifting body

2016

View full text Add to dashboard Cite

A straightforward evaluation approach of free-surface Green function is developed to solve the potential flow around a three-dimensional lifting body. The free-surface waves generated by the movement of the lifting body is presented in an expansion of plane regular waves traveling in θ directions with wave number magnitudes k > 0. A boundary element method is combined with the evaluation approach and Hess-Smith panel integral formulae to predict hydrodynamic performance of a three-dimensional lifting body. Numerical results produced by the proposed method are compared favourably with experimental measurements.

show abstract

“…A numerical computation study on the effect of the position of the placement of hydrofoil on ship resistance in towing tanks found that positioning the main foil closer to the LCG generates smaller resistances [6]. The shape and angle of attack of hydrofoil also affect the lift-drag coefficient and the form factor [7], However, the high demand for ships that can carry heavier loads and can operate at high speeds encourages the development of hydrofoil vessels that have larger load capacities at high speeds and have better seakeeping performance [8],…”

Section: Introductionmentioning

confidence: 99%

Effect of the Addition of Hydrofoil on Lift Force and Resistance in 60 M High-Speed Vessel

Ismail

Manik

Indiaryanto

2020

Kapal

View full text Add to dashboard Cite

The development of sea transportation technology is needed to meet the demand for ships that can carry heavier loads and operate at high speeds. Modifications in the form of additional hydrofoil variations were conducted to produce higher lift and reduce the resistance generated by the ship so that the ship can go more efficiently at high speed. This study aims to obtain the effect of adding hydrofoil to ships with variations in the type and shape of foil and find out which types and shapes can reduce resistance on the ship. This research was conducted with several model analysis tests using Computational Fluid Dynamic (CFD) based software, namely Tdyn, at several different speeds. The results of this study show that of the six variation models analyzed, rectangular fully submerged foil models can reduce the total resistance value of the ship by 17.822% from the original ship on Froude Number (Fr) 0.670. The type and shape of the foil is very influential on the lift and resistance produced by the ship.

show abstract

Analytical modelling for a three-dimensional hydrofoil with winglets operating beneath a free surface

Cited by 16 publications

References 35 publications

Nonlinear lifting theory for unsteady WIG in proximity to incident water waves. Part 2: Three-dimension

Nonlinear lifting theory for unsteady WIG in proximity to incident water waves. Part 2: Three-dimension

Straightforward discretisation of Green function and free-surface potential flow around a three-dimensional lifting body

Effect of the Addition of Hydrofoil on Lift Force and Resistance in 60 M High-Speed Vessel

Contact Info

Product

Resources

About