Ship hull drag reduction using bottom air injection

Latorre, Robert

doi:10.1016/0029-8018(96)00005-4

Cited by 84 publications

(23 citation statements)

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“…Stable air cavities can substantially reduce frictional resistance by decreasing the wetted surface area. A review of early developments of air-cavity ships and boats is given by Latorre (1997). Air-cavity landing craft and small fast ferries are already built in series (Matveev, 2005).…”

Section: Introductionmentioning

confidence: 99%

Hydrodynamic modeling of semi-planing hulls with air cavities

Matveev

2015

International Journal of Naval Architecture and Ocean Engineeri

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High-speed heavy loaded monohull ships can benefit from application of drag-reducing air cavities under stepped hull bottoms. The subject of this paper is the steady hydrodynamic modeling of semi-planing air-cavity hulls. The current method is based on a linearized potential-flow theory for surface flows. The mathematical model description and parametric calculation results for a selected configuration with pressurized and open air cavities are presented.

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Section: Introductionmentioning

confidence: 99%

Hydrodynamic modeling of semi-planing hulls with air cavities

Matveev

2015

International Journal of Naval Architecture and Ocean Engineeri

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“…However, in real-world applications, when this reduction technique is employed on a full-scale vessel, it is difficult to ensure that the bubbles remain within the boundary layer due to their buoyancy, and as a result, the reduction efficiency drops greatly. Latorre [9] utilized the microbubble drag reduction technique on both small-scale models and full-scale ships; the efficiencies of drag reduction were 10-12 and 15-18% for the model ships and full-scale ships, respectively. In the full-scale ship experiments conducted by Kato and Kodama [10], the authors operated an underwater TV camera and observed that the bubbles did not spread thinly over the ship's hull, and instead formed likely chimney smoke downstream.…”

Section: Introductionmentioning

confidence: 99%

Robust design and numerical simulation on drag reduction by a mixture film for liquid turbulence in a channel

Ouyang

Shiah

2008

Numerical Methods in Fluids

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SUMMARYAn important way of increasing the speed and lowering the fuel consumption of ships is by decreasing the frictional drag. One of the most promising techniques for reducing drag is the use of air bubbles. The goal of this investigation is to establish a set of optimum robust parametric levels for drag reduction by a mixture (air-water) film in turbulent channel flow. Based on the conditions laid out by the Taguchi orthogonal array method, turbulent flows, with air bubbles injected into a channel, are simulated using commercial computational fluid dynamics software. The local shear stress on the upper wall is computed to evaluate the efficiency of drag reduction. Many factors can affect drag reduction. The factors investigated in this study are the rate of air injection, bubble size, area of air injection, flow speed, and measured position of the shear stress. These factors have been investigated through the analysis of variance, which has revealed that the rate of air injection and water flow speed dominate the efficiency of drag reduction by a mixture film. According to the results, the drag can be reduced by an average of 83.4%; and when the configuration of the parametric levels is optimum the maximum drag reduction of 88.5% is achieved.

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“…Within the field of air lubrication there are a variety of techniques that have been suggested since the 19 th century (Latorre, 1997). Air lubrication can be divided into three main types: Bubble Drag Reduction (BDR) (Kodama et al 2000;Madavan et al, 1985); Air Layer Drag Reduction (ALDR) (Elbing et al, 2008); and Partial Cavity Drag Reduction (PCDR) (Butuzov, 1967;Butuzov et al, 1999).…”

Section: Introductionmentioning

confidence: 99%