The interceptor hydrodynamic analysis for controlling the porpoising instability in high speed crafts

Mansoori, M.; Fernandes, Antonio Carlos

doi:10.1016/j.apor.2016.02.006

Cited by 42 publications

(19 citation statements)

References 4 publications

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“…In other words, a novel constructive phenomenon named Honaryar has occurred for the sake of decreasing separation in semi-planing or planing mode by which not only does the total drag decreased but also the lift force increased as well as it is having center of pressure move backward. Therefore it causes lessening the risk of porpoising instability since for diminishing the risk of porpoising in addition to reducing trim angle, the lift coefficient must be increased too [92]. By carefully observing Fig.…”

Section: Resultsmentioning

confidence: 99%

A new phenomenon in interference effect on catamaran dynamic response

Honaryar

Ghiasi

Liu

2021

International Journal of Mechanical Sciences

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Interference effect between catamaran demi-hulls has been considered as an adverse fluid-solid interaction; the narrower separation distance between the two hulls, the greater drag force acts upon the catamaran. However, this study is aimed at introducing a novel phenomenon contrasting outcome in semi-planing and planing regimes. As speed and accordingly the Froude number increase the catamaran transits across different modes, free surface profile becomes complicated and so does the interference effect as well as the prediction of catamaran dynamic response. The situation will be even more complex if demi-hull separation narrows where nonlinearity in interference effect is more pronounced. So, free-running tests in six degrees of freedom as well as obtaining fluid flow characteristics using computational fluid dynamics were conducted for a high-speed catamaran vehicle with asymmetric non-prismatic demi-hulls to tackle the problem. The results of catamaran dynamic response reveal that not only is drag reduced substantially up to 15%, but also trim angle diminishes by 30% as hulls separation distance decreases in semi-planing and planing modes. In other words, with increasing speed, and decreasing trim angle by 2.3 o , the current method achieved the goal of consequently reducing the risk of porpoising instability, without the increase of delivered power.

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Section: Resultsmentioning

confidence: 99%

A new phenomenon in interference effect on catamaran dynamic response

Honaryar

Ghiasi

Liu

2021

International Journal of Mechanical Sciences

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“…The distance metric to the asymptotic range is defined as P G = P G RE P G th (19) where P G th is the theoretical order of accuracy. The grid uncertainty is expressed by The results of uncertainty verification and validation were summarized in Table 5.…”

Section: Results and Discussion A Grid Verification And Validationmentioning

confidence: 99%

“…The VOF model is widely applied to track the interface between water and air. This method represents the volume fraction of the q ∧ th fluid in each control unit as α q , and there are generally the three conditions [19]: α q = 0 : the q ∧ th fluid doesn't exist in the unit; α q = 1 : there is only the q ∧ th fluid in the unit; 0 < α q < 1 : an interface exists in the unit. Besides, the volume fraction continuity equation should be considered in the governing equations:…”

Section: B Mathematical Model and Governing Equationsmentioning

confidence: 99%

Influence on Stern Flaps in Resistance Performance of a Caterpillar Track Amphibious Vehicle

Sun

Wang

2020

IEEE Access

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In order to reduce the resistance and increasing speed for a caterpillar track amphibious vehicle (CTAV), the stern flaps were applied and the influence was researched. Numerical simulations performed by STAR-CCM+ and model towing test reveal that stern flaps have greatly reduced the resistance, trim, and sinkage of the CTAV when the length Froude number is between 0.63 and 1.05. The length and flap angle were optimized by numerical simulation. In addition, the residual resistance plays a dominant role in resistance reduction, which contributes to more than 90% of the total resistance reduction. Installing stern flaps increase the vehicle waterline by 7% and enhance the virtual-length effect. Furthermore, the running attitude becomes steadier, thereby decreasing the trim and sinkage. Therefore the resistance performance of the CTAV can be enhanced by installing stern flaps with a proper length at an optimal flap angle. INDEX TERMS Caterpillar track amphibious vehicle, CFD, resistance performance, running attitude, STAR-CCM+.

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“…33 One way to reduce the porpoising phenomenon of high-speed crafts is the use of lift producers like interceptor(s), wedge (s) or trim tab (s) at the transom. Mansoori and Fernandes, 34 through a numerical study, verified that porpoising can be controlled by interceptors. One of the most influential parameters in the design of the interceptors is the height.…”

Section: Introductionmentioning

confidence: 86%

Experimental and numerical analyses of wedge effects on the rooster tail and porpoising phenomenon of a high-speed planing craft in calm water

Sajedi

Ghadimi

Sheikholeslami

et al. 2019

Proceedings of the Institution of Mechanical Engineers, Part C:

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This paper presents experimental and numerical investigation of stability and rooster tail of a mono-hull high-speed planing craft with a constant deadrise angle. Initially, a one-fifth scale model was tested in a towing tank, which showed porpoising phenomenon at 8 m/s (equal to the speed of sailing). Subsequently, two wedges of 5 and 10 mm heights, based on the boundary layer calculations, were mounted on the aft section of the planing hull. These wedges were shown to increase the lift at the aft section. These experiments were carried out at different speeds up to 10 m/s in calm water. The experimental results indicated that the installed wedges reduced the trim, drag, and the elapsed time for reaching the hump peak, and also eliminated the porpoising condition. All these test cases were also numerically simulated using Star CCM+ software. The free surface was modeled using the volume of fluid scheme in three-dimensional space. The examined planing craft had two degrees of freedom, and overset mesh technique was used for space discretization. The obtained numerical results were compared with experimental data and good agreement was displayed in the presented comparisons. Ultimately, the effect of the wedge on the rooster tail behind the planing craft was studied. The results of this investigation showed that by decreasing the trim at a constant speed, the height of the generated wake profile (rooster tail) behind the craft decreases, albeit its length increases.

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The interceptor hydrodynamic analysis for controlling the porpoising instability in high speed crafts

Cited by 42 publications

References 4 publications

A new phenomenon in interference effect on catamaran dynamic response

A new phenomenon in interference effect on catamaran dynamic response

Influence on Stern Flaps in Resistance Performance of a Caterpillar Track Amphibious Vehicle

Experimental and numerical analyses of wedge effects on the rooster tail and porpoising phenomenon of a high-speed planing craft in calm water

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