仿生水下滑翔机滑翔运动数值仿真研究

Numerical simulation on gliding motion ofbionic underwater glider

摘要:

水下滑翔机是一种利用重力与浮力之差获取动力的水下航行器,其通常具有造价低、隐身性能强等优点。随着人类对海洋环境更深入的探索,水下滑翔机被广泛应用于观测海洋环境等民事和军事任务。在此背景下,对水下滑翔机的滑翔运动进行准确的预报并分析影响滑翔运动的因素具有重要意义。本文使用基于RANS(Reynolds-Averaged Navier-Stokes)方程的计算流体力学(Computational Fluid Dynamics,CFD)方法,并结合动态重叠网格方法,对仿生水下滑翔机的滑翔运动进行了模拟,研究了航行过程中水下滑翔机的重心位移和净浮力对滑翔运动的影响,给出了滑翔速度比随重心移动和净浮力变化的变化趋势,同时对水下滑翔机所受的横滚和偏航力矩进行了分析。结果显示,当净浮力大小为3%的滑翔机重力时,仅移动重心即可使滑翔速度比达到4以上。该研究能够对水下滑翔机的设计提供一定的参考。

关键词:计算流体力学;数值模拟;水下滑翔机;仿生;滑翔运动

Abstract:

Underwater glider is an underwater vehicle that uses the difference between gravity and buoyancy to obtain power. Underwater glider usually has the advantages of low cost and high stealth performance. With the deeper exploration of the marine environment, underwater gliders are widely used in civil and military missions such as observing the marine environment. In this context, it is of great significance to accurately predict the gliding movement of underwater gliders and analyze the factors affecting gliding movements. The Computational Fluid Dynamics (CFD) method based on the RANS (Reynolds-Averaged Navier-Stokes) equation combined with the dynamic overlap method is applied to the direct simulation of a bionic underwater glider. The effects of the center of gravity displacement and net buoyancy of the underwater glider on the gliding motion during the navigation are studied. The trend of gliding speed ratio with the displacement of the center of gravity and net buoyancy is given and the roll and yaw moments experienced by the underwater glider are also analyzed. In the results, when the net buoyancy is 3% of the glider"s gravity, moving the center of gravity can achieve a gliding speed ratio of more than 4. This study can provide a certain reference for the design of underwater gliders.

Key words:computational fluid dynamics; numerical simulation; underwater gliders; bionic; gliding movement