摘要
近年来,涵道螺旋桨作为一种性能优异的推进器被广泛应用于各种垂直起降无人机中,但国内关于其地面效应的研究还较少。针对此,文中使用了基于雷诺平均Navier-Stokes方程和多重参考坐标系的求解方法,通过数值仿真分别计算了不同离地高度下,3种不同桨叶数的涵道螺旋桨各部件所受力和力矩的变化情况。并结合计算流体动力学计算结果分析了气动特性变化机理,结果表明在近地高度达到一定值时,涵道螺旋桨的气动特性发生显著变化,螺旋桨部分升力增大但涵道部分升力减小,系统整体所受反扭矩增加。最终量化成升力系数、功率系数和品质因子的变化,发现随着离地高度的降低,功率系数明显增大,涵道螺旋桨的升力系数和品质因子的变化与螺旋桨桨叶数有关。由此得到了地面效应对涵道螺旋桨气动特性影响的初步结论。
In recent years,ducted fans,as a kind of propeller with excellent performance,have been widely used in various vertical take-off and landing(VTOL)unmanned aerial vehicles(UAVs).However,there is less research on its ground effect in China.Therefore,in this paper,a solution method based on Reynolds mean Navier-Stokes(RANS)equations and multiple reference coordinate system(MRF)was used.Through numerical simulation,the force and torque changes of each part of the ducted fans with three different blade numbers at different elevations were calculated.The changing mechanism of aerodynamic characteristics was analyzed by calculation results of computational fluid dynamics.The results show that when the altitude near the ground reaches a certain value,the aerodynamic characteristics of the ducted fans change significantly.The lift force of the propeller increases,but that of the duct decreases,and the reverse torque of the whole system increases,which were finally quantified as the variation of lift coefficient,power coefficient,and quality factor.The power coefficient increases significantly with the decrease in the elevation,and the variation of lift coefficient and quality factor of the ducted fans is related to the number of propeller blades.A preliminary conclusion on the influence of ground effect on the aerodynamic characteristics of ducted fans is thus obtained.
作者
周煜
陈伟政
ZHOU Yu;CHEN Weizheng(China Ship Scientific research center,Wuxi 214082,China;Taihu Laboratory,Wuxi 214082,China)
出处
《水下无人系统学报》
2023年第6期942-948,共7页
Journal of Unmanned Undersea Systems
关键词
垂直起降无人机
涵道螺旋桨
地面效应
气动特性
vertical take-off and landing unmanned aerial vehicle
ducted fan
ground effect
aerodynamic characteristics
