A novel air bubble lubrication method using the winged air induction pipe (WAIP) device is used to reduce the frictional drag of the hull of the ship and hence increase the efficiency of the propulsion system. This bubble lubrication technique utilizes the negative pressure region above the upper surface of the hydrofoil as the ship moves forward to drive air to the skin of the hull. In the present study, the reduction rate of the drag by applying the WAIP device is numerically investigated with the open source toolbox OpenFOAM. The generated air layer and the bubbles are observed. The numerical results indicate that the reduction rate of the drag closely depends on the depth of the submergence of the hydrofoil, the angle of attack of the hydrofoil, and the pressure in the air inlet. It is also proportional to the air flow rate. The underlying physics of the fluid dynamics is explored.

中文翻译：

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船舶壳体上采用空气层概念的摩擦减阻的数值研究

使用带翼进气管（WAIP）装置的新型气泡润滑方法可减少船体的摩擦阻力，从而提高推进系统的效率。这种气泡润滑技术在船向前移动时利用水翼机上表面上方的负压区域将空气驱动到船体的表皮。在本研究中，使用开源工具箱OpenFOAM对使用WAIP设备的阻力减小率进行了数值研究。观察到产生的空气层和气泡。数值结果表明，阻力的减小速度密切取决于水翼的浸没深度，水翼的迎角和进气口的压力。它也与空气流量成正比。