A Numerical Investigation of the Water Impact of an Arbitrary Bow Section

Ghadimi, Parviz; Chekab, Mohammad A. Feizi; Dashtimanesh, Abbas

doi:10.1080/09715010.2013.796690

Cited by 26 publications

(16 citation statements)

References 14 publications

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“…In brief, the above equations describe the superposition of the effects of particles j on the particle i with respect to the smoothing function W which imposes a weighting on the effects of particles j regarding their distances to the particle i. Derivation of these equations using the integral form of the equations and by applying smoothing functions has been previously described by Liu and Liu (2003) and the present authors [15][16][17][18] and hence, is not repeated here. It should be mentioned that cubic spline smoothing function is used as follows:…”

Section: Governing Equations and The Sph Methodsmentioning

confidence: 94%

Investigation of three-dimensionality effects of aspect ratio on water impact of 3D objects using smoothed particle hydrodynamics method

Chekab

Ghadimi

Farsi

2015

J Braz. Soc. Mech. Sci. Eng.

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Section: Governing Equations and The Sph Methodsmentioning

confidence: 94%

Investigation of three-dimensionality effects of aspect ratio on water impact of 3D objects using smoothed particle hydrodynamics method

Chekab

Ghadimi

Farsi

2015

J Braz. Soc. Mech. Sci. Eng.

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“…It is considered that the model passes through a transverse plane and the three dimensional problem can be reduced to a water entry of a solid body with wedge section, as shown in Figure 19. Dynamic pressure distribution over the wall of the wedge can be computed using analytical scheme, numerical methods [52][53][54][55][56][57][58][59][60][61][62][63][64][65][66][67] or experimental measurements [68][69][70][71][72][73][74]. Here, the Wagner solution [75] is used as in when the water has not drenched the chine.…”

Section: Longitudinal Force Distributionmentioning

confidence: 99%

Experimental Study of the Wedge Effects on the Performance of a Hard-chine Planing Craft in Calm Water

2018

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In this paper, effects of a wedge on the performance of planing craft in calm water are experimentally investigated. Experiments are carried out on three different cases distinguished by the wedge type. The model, built of fiberglass, is a prismatic planing hull with deadrise angle of 24 degrees. Towing tests are conducted at different Froude numbers ranging from 0.21 to 2.1. The total trim angle, resistance, rise up at the CG as well as stern and bow, keel wetted length, chine wetted length, stagnation angle, and the length of stagnation line are measured. They are used to study the effect of installing a wedge on the performance as well as the effect of height on the hydrodynamic characteristics. Based on the observations made, it is concluded that, when the wedge is applied to the hull, the risk of model exhibiting instability diminishes, while total trim angle largely decreases, keel wetted length is enlarged, wetted surface becomes thinner, CG rise up is lowered, and the resistance is reduced. Moreover, experimental measurements and theoretical 2D+T theory are combined to bring deeper insight about physics of the flow and pressure distribution when a wedge is installed on the bottom of a planing hull.

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“…Recently, there has been good progress in numerical modeling of the flow related to water entry problems. Application of analytical method by Ghadimi et al [25], URANS method by Ghadimi et al [26][27][28], as well as SPH simulations by Farsi and Ghadimi [29][30][31] and Feizi Chekab et al [32] in simulations of water entry of different objects have suggested that numerical solution of the viscous flow may be an appropriate choice for analyzing flow around wedges. The main objective of the current paper is to offer further contribution to the understanding of cavitation phenomenon in surface piercing propellers through the usage of computational fluid dynamics and by investigating flow around a wedge.…”

Section: Introductionmentioning

confidence: 99%

Probing Into the Effects of Cavitation on Hydrodynamic Characteristics of Surface Piercing Propellers Through Numerical Modeling of Oblique Water Entry of a Thin Wedge

Javanmardi

Ghadimi

Tavakoli

2017

brod

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SummaryThe current paper investigates flow around a blade section of a surface piercing hydrofoil. To this end, a thin wedge section is numerically modelled through an oblique water entry. The flow is numerically studied using a multiphase approach. The proposed numerical approach is validated in two steps. First, pressure and free surface around a wedge entering water are simulated and compared against previously published analytical results. Subsequently, cavitation phenomenon around a submerged supercavitating hydrofoil is modelled and analyzed. It is observed that cavity length, pressure, and lift force are accurately predicted. Subsequently, the main problem has been studied for two different cavitation numbers for a range of advanced ratios equivalent to fully, transition and partially ventilated conditions in order to investigate the effect of ambient pressure on hydrodynamics of the water entry of the foil. The numerical findings reveal that, when the cavitation number decreases, the start of transition mode is postponed and this mode is expanded for the larger range of velocity ratios. This implies that fully ventilated velocity ratio modes are expanded, too. However, in the transition mode, the cavitation number plays an essential role and may lead to a decrease in the pressure difference across the surface piercing hydrofoil which yields a decrease in the resultant force.

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A Numerical Investigation of the Water Impact of an Arbitrary Bow Section

Cited by 26 publications

References 14 publications

Investigation of three-dimensionality effects of aspect ratio on water impact of 3D objects using smoothed particle hydrodynamics method

Investigation of three-dimensionality effects of aspect ratio on water impact of 3D objects using smoothed particle hydrodynamics method

Experimental Study of the Wedge Effects on the Performance of a Hard-chine Planing Craft in Calm Water

Probing Into the Effects of Cavitation on Hydrodynamic Characteristics of Surface Piercing Propellers Through Numerical Modeling of Oblique Water Entry of a Thin Wedge

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