Modeling of steady motion and vertical-plane dynamics of a tunnel hull

Chaney, Christopher S.; Matveev, Konstantin I.

doi:10.2478/ijnaoe-2013-0182

Cited by 6 publications

(2 citation statements)

References 7 publications

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“…However, these motions subsequently increase as Fr=1.11 until 1.39. This result analysis was reasonable since the monotricat ship geometrically provided hydrostatics support at low speed; while predominantly offered high dynamics lift at high speed [25]. Comparing to the monotricat ship without steppedhull, the heave and pitch motions of the monotricat ship with stepped-hull has lower heave and pitch motions from Fr=1.11 up to 1.39 (see Table 4).…”

Section: Effect Of Froude Number (Fr)mentioning

confidence: 52%

Heave and pitch motions performance of a monotricat ship in head-seas

Fitriadhy¹,

Adam²

2017

Int. J. Automot. Mech. Eng.

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A reliable investigation which allows an accurate prediction on seakeeping performance of a monotricat ship in head-seas is obviously required. To achieve this objective, a Computational Fluid Dynamic simulation approach is proposed by looking into attainable outcomes with precision, whilst a hydrodynamic description that is underlying the rationale behind the results is explained. Two conditions of the monotricat ship model, termed as with and without stepped-hull, were employed in the computational simulation. Several wave properties, such as various wavelengths and wave heights on heaving and pitching performances associated with different Froude number (Fr) were taken into account. The results showed that the increase of Fr was proportional with the increase the heaving and pitching motions. These led to the downgrade seakeeping performances presented in the form of high Response Amplitude Operators (RAO). In shorter wavelengths (λ<1), RAO of the heave and pitch motions were insignificant. However, the subsequent increase of wavelength (λ>1) was proportional with the increased RAO of the heave and pitch motions. The further increase in wavelength (>1.75) resulted in less RAO both of the heave and pitch motions. The increase in wave height had affected a proportionate increase in the heave and pitch motions that may possibly lead to degrade her seakeeping quality. It can be concluded that the effects of Fr and wavelength on the heave and pitch motions of the monotricat ship had more complex phenomenon as compared to the wave-height ones. These CFD results are useful as preliminary prediction for navigation safety during sailing.

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Section: Effect Of Froude Number (Fr)mentioning

confidence: 52%

Heave and pitch motions performance of a monotricat ship in head-seas

Fitriadhy¹,

Adam²

2017

Int. J. Automot. Mech. Eng.

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“…Ghassabzadeh et al numerically simulated the hydrodynamic performance of a multihull tunnel vehicle based on FLUENT software, and the results indicated that the accuracy was acceptable [9,10]. Chaney introduced a numerical model based on fully unsteady aerodynamic extreme-ground-effect theory and the hydrodynamic added-mass strip theory for tunnel hull vertical plane dynamics in wind gust and wave simulations [11]. Moghadam et al discussed and compared the performance between a tunnel hull and its parent monohull based on the k-ε model.…”

Section: Introductionmentioning

confidence: 99%

Experimental Study on Motion Behavior and Longitudinal Stability Assessment of a Trimaran Planing Hull Model in Calm Water

Zeng

Sun

et al. 2021

JMSE

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In this study, a high-speed planing trimaran hull form is designed, and the effects of different displacements and gravity longitudinal layouts on the performance of the trimaran planing hull in calm water are experimentally investigated in the towing tank of the China Special Vehicle Research Institute. Based on previous work, an innovative inner tunnel appendage hydroflap is mounted in the inner aft tunnel, located 1/8 L from the transom in the longitudinal direction with attack angles of 0° and 4°, respectively. Furthermore, a regular stern flap is mounted on the transom close to the chine. The towing test results show that, as the gravity center moves forward, the high-speed region resistance of the planing trimaran increases and the longitudinal stability is also strengthened. Further, the total resistance of the planing trimaran with a heavier displacement is larger while the average mass resistance declines; i.e., the resistance efficiency is improved. The results also indicate that the inner tunnel hydroflap and stern flap enhance the aft hull hydrodynamic lift and tunnel aerodynamic lift. As a result, mounting aft hull lift enhancement appendages can affect the bottom and inner tunnel pressure distribution and then cause a slight resistance decrease in the low-speed region. The value relationship of resistance between groups of appendages for the attached hull and bare hull is reversed at a speed of about Froude number 3.0. Although the aft hull lift enhancement appendages result in a higher resistance cost in the high-speed region, the longitudinal stability is effectively promoted and the occurrence speed of porpoising results in a delay of 1 to 2 m/s.

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