自主水下机器人强制自航下潜的类物理模拟

Physics-Based Simulation of AUV Forced Diving by Self-Propulsion

为提高自主水下机器人(AUV)下潜的安全性和稳定性,需对AUV自航下潜操纵运动进行精确预报.为此提出建立载体全物理模型,模拟螺旋桨运动,编写用户自定义函数(UDF),求解雷诺平均N-S方程,实时预报载体强制自航下潜运动受力和流动特性的类物理数值模拟方法.该方法采用多块混合网格和动区域法,能提高动网格数值模拟的精度和计算效率.数值方法通过AUV自航试验的速度对比进行了验证.将该方法应用于AUV强制自航下潜模拟,结果表明:初始启动时,载体加速度较大,将导致AUV有较大纵向和垂向阻尼;在载体纵倾变化过程中,载体垂向力幅值较大且振荡,螺旋桨尾迹有扭转趋势,螺旋桨推力变化;在载体定向直航下潜中,螺旋桨推力和载体阻力较为稳定.

It is necessary to predict accurately the maneuverability of autonomous underwater vehicle(AUV)diving by self-propulsion to improve its safety and stability.A method was presented to predict the vehicle’s forces and flow details in real time during forced diving motion.A full appended model was built,the propeller’s rotating motion was simulated,and coupled with user defined function(UDF),the Reynolds-averaged Navier-Stokes(RANS)equations were solved.This method can improve the accuracy and computation efficiency of the dynamic mesh method by using multi-block mesh with the moving zone method.The numerical method was validated by comparison of the computational and experimental results of AUV’s velocity in AUV self-propulsion test.The numerical results of AUV forced diving by self-propulsion showed that,at the initial time,the AUV had a large acceleration which resulted in a large resistance.When the pitch changed,the vertical force oscillated.The wake of the propeller twisted and the thrust of the propeller varied.In steady diving,the thrust and resistance became steady.