附加质量对大展弦比无人机动力学的影响

Effects of apparent mass on dynamics of UAV with high aspect ratio

大展弦比无人机在空中飞行时,其机翼将改变周围气流的动能进而产生附加质量。为了研究所产生的附加质量对大展弦比无人机动力学特性的影响,采用Barrows矩阵建立大展弦比无人机的附加质量矩阵,采用多体动力学方法将大展弦比无人机划分为左右机翼、机体、螺旋桨的多刚体系统,基于Gibbs-Appell方程推导并建立了大展弦比无人机的动力学模型。通过仿真结果发现:当无人机作沉浮运动时,多体动力学建模与单刚体建模结果一致,证明了多体动力学建模思路的正确性;引入大展弦比无人机的附加质量矩阵后,其对无人机的沉浮运动无较大影响,但在无人机作盘旋运动时,与未引入附加质量矩阵相比仍存在10%的差异。

When a UAV with high aspect ratio flies in the air, its wings change the kinetic energy of the surrounding airflow to produce the apparent mass. To study the effects of the apparent mass on the dynamics of the UAV, firstly, the Barrows matrix was adopted to establish the apparent mass matrix of the UAV with high aspect ratio. Secondly, based on the method of multibody dynamics, the UAV was divided into a multi-body system including the left wing, the right wing, the body and the propeller. Finally, the dynamic model of the UAV with high aspect ratio was deduced and established based on the Gibbs-Appell equation. The simulation results show that: when the UAV conducts up and down motion, the multi-body dynamic modeling results are consistent with the results of single-rigid-body dynamic modeling, thus proving the accuracy of the idea of the multi-body modeling;the introduction of the apparent mass matrix has no significant effects on the up and down motion of the UAV, but when the UAV steady turn, there is a 10% difference compared with that without apparent mass matrix.