四旋翼飞行器涡环状态非定常气动载荷变化特征研究  

Characterization of Non-constant Aerodynamic Load Changes in the Vortex Ring State of a Quadrotor Aircraft

作　　者：李垠翰 吴令华 苏大成 侯祥民 LI Yinhan;WU Linghua;SU Dacheng;HOU Xiangmin(National Key Laboratory of Helicopter Aeromechanics,China Helicopter Research and Development Institution,Jingdezhen 333001,China)

机构地区：[1]中国直升机设计研究所直升机动力学全国重点实验室,江西景德镇333001

出　　处：《直升机技术》2024年第4期22-28,33,共8页Helicopter Technique

摘　　要：运用分离涡(DES)与嵌套网格相结合的方式,对涡环状态下四旋翼飞行器的非定常气动载荷变化特征进行了研究。重点从四旋翼飞行器干扰耦合流场的涡量场、速度场等角度分析了多旋翼之间的气动干扰对涡环特性的影响及内在机理。结果表明:在悬停状态下及涡环状态前期,旋翼间的气动干扰使得各个旋翼的拉力产生明显的非定常波动,其波动幅值达到12%;进入涡环状态中期,由于旋翼之间区域内的涡结构发生干扰和耗散现象,在该区域内没有出现明显的环流,但在旋翼桨盘其他区域,脱落的涡结构向上卷起并被重新吸入,导致旋翼拉力减幅达到31%,且非定常波动幅度增大至16%;到了后期阶段,或称风车状态,相邻旋翼的桨尖涡相撞后拉伸并破裂,桨根涡也迅速破裂,在桨盘上方形成细碎的涡结构,导致旋翼非定常波动的周期明显增大,且拉力比悬停时增加41%。This study investigated the characteristics of unsteady aerodynamic loads on quadrotor helicopters under vortex ring conditions using a combination of separated vortex(DES)and nested grid techniques.The analysis focused on the impact of aerodynamic interference between quadrotors on vortex ring characteristics and the underlying mechanisms.The results indicated that during hover and vortex ring initiation phase,aerodynamic interference between the rotors caused significant,non-steady fluctuations in the thrust of each rotor,with a fluctuation ratio reaching 12%.In the vortex ring maturation phase,due to the interference and dissipation of vortices within the rotor-to-rotor region,no obvious vortex ring was observed in this region.However,the detached vortices rolled up and re-entered the rotor,resulting in a reduction in rotor thrust of 31%and an increase in non-steady fluctuation amplitude to 16%.In the later stage,or as the windmill state,vortices between neighboring rotors collided,stretched,and ruptured.The rotor root vortices also rapidly ruptured,forming fine-scale vortices above the rotor disc,causing a significant increase in the cycle of rotor non-steady fluctuations and a 41%increase in thrust.

关 键 词：涡环状态 四旋翼 气动特性 非定常 

分 类 号：V211.52[航空宇航科学与技术—航空宇航推进理论与工程]