水下滑翔器浮力驱动效率分析

Analysis of the Propulsion Efficiency of Buoyancy-driven Underwater Gliders

水下滑翔器作为一种新型水下机器人系统,由于采用了浮力驱动技术具有续航能力大、效率高、噪声低等优点,对于海洋环境监测与资源探测具有重要的应用前景。基于此,对做匀速滑翔运动的水下滑翔器驱动能量进行分析,给出水下滑翔器驱动效率的概念,并推导水下滑翔器在考虑额外能耗与不考虑额外能耗这两种情况下浮力驱动效率的计算方法,进一步分析影响驱动效率的相关因素和提高驱动效率的途径。通过分析可知,机翼的升阻比与滑翔额外能耗是影响浮力驱动效率的两个主要因素,其中机翼的升阻比是影响驱动效率的最重要因素。为揭示驱动效率和机翼结构参数和机翼形式之间的关系,采用经验公式分析机翼展弦比、后掠角对机翼升阻比的影响,采用流体力学计算软件Fluent6.2对相同面积的不同形式机翼的升阻比进行数值计算。研究结果为水下滑翔器设计提供了依据。

As a new type of autonomous underwater vehicle, the underwater glider has many advantages such as long endurance, high propulsion efficiency, and low self-noise due to the application of buoyancy-driven technology. It has promising applications in the oceanographic survey and ocean exploration. The propulsion energy when the underwater glider dives and ascends with a constant velocity is analyzed. The propulsion efficiency is then defined on the basis of this analysis and the calculation methods are derived with and without consideration of the extra energy losses. Investigation is also conducted to figure out factors that influence the efficiency and methods for improving the efficiency. The lift-to-drag ratio of wings and the extra energy losses are found to be the main factors influencing the propulsion efficiency and the lift-to-drag ratio of wings is the most important factor. In order to reveal the relationships between the propulsion efficiency and the structure parameters and the forms of the glider wings, the effect of the aspect ratio and the sweep angle of wings on the lift-to-drag ratio are investigated by using an empirical equation, and the lift-to-drag ratio of wings with same area but different forms are also calculated by using computational fluid dynamics software Fluent 6.2. The results provide an insight into the underwater glider design.