某中空长航时无人机机载浮标分离安全性研究

研究机载浮标投放过程中气动干扰特性及浮标运动规律,对机载浮标安全投放方案的设计具有重要意义。采用计算流体力学方法对机载浮标投放过程进行数值模拟。通过动态嵌套网格技术模拟浮标运动,结合刚体六自由度运动方程求解三维非定常 N-S ( Navier-Stokes )方程,模拟基于察/打一体无人机平台的浮标自由投放过程,获得详细的包括浮标运动姿态、运动轨迹和受力情况等在内的数据信息;通过算例,验证本文数值模拟程序的准确性。结果表明:浮标投放过程中,轻质浮标口盖自由分离会对螺旋桨后推式无人机的安全性造成重大影响;考虑浮标口盖固连在浮标降落伞上的状态下,初速度为 0m / s 时投放浮标整体(包含浮标、降落伞、口盖)离螺旋桨最近距离为 0.151m ,安全余量不够;初速度为 1.8m / s 时投放浮标整体离螺旋桨最近距离为 0.671m ,满足投放安全性要求。

Safety Research on Release of Airborne Buoy based on a Medium and long-endurance(MALE) UAV

In order to study the aerodynamic interference and movement rules of external store, computational fluid dynamics (CFD) methods were used to simulate the release process of airborne buoy in R/S UAV. A Moving-embedded grid approach is used coupled with an unsteady N-S equations, and a 6-DOF kinetic equations is fully integrated into the CFD solution procedure to capture the time-dependent interference between the stationary and moving boundaries. All major parameters, such as displacement, angular orientations and force, and their change trends were obtained. The results show that free separation of buoy cover could have a significant impact on the safety of UAV during the release process of airborne buoy. Consider the state of the buoy cover attached to the buoy parachute, the closest range of buoy from the propeller is 0.151m when the initial speed is 0.0 m/s, the safety margin is not enough; however, the closest range of buoy from the propeller is 0.671m when the initial speed is 1.8 m/s, the safety margin is enough.