Instantaneous force and structural deformation experiments were performed on a flexible, structurally characterized, low-aspect-ratio representative flapping wing. A six-component force balance was used to measure aerodynamic-force time history over a flap cycle. A VICON motion capture setup tracked the wing deformations while flapping. Measured aerodynamic forces and wing deformations were compared against coupled computational fluid dynamics/computational structural dynamics (CFD/CSD) aeroelastic analysis results. The CFD solver is an unsteady Reynolds-averaged Navier–Stokes solver. The CSD solver is a general-purpose multibody dynamics solver capable of modeling geometrically nonlinear beam and shell elements. The CFD/CSD results were able to capture the overall trend in aerodynamic forces and wing deformations. Although predicted and measured variations in lift were similar, the drag-force magnitudes tended to be underpredicted by the coupled aeroelastic solver. The coupled CFD/CSD solver was used to evaluate the influence of wing flexibility on wing performance. Results showed that, in particular instances, decreasing wing stiffness increased the time-averaged aerodynamic lift and lift-to-power ratio. Decreased wing stiffness led to reduced leading-edge vortex circulation strength. This suggests that the increased wing performance is mainly due to a redirection of the resultant force vector allowed by the increased wing compliance.

瞬时力和结构变形实验是在一个灵活的、结构特征的、低展弦比的代表性扑翼机翼上进行的。六分量力平衡用于测量襟翼周期内的空气动力时间历程。VICON 动作捕捉设置跟踪拍打时的机翼变形。将测量的空气动力和机翼变形与耦合计算流体动力学/计算结构动力学 (CFD/CSD) 气动弹性分析结果进行比较。CFD 求解器是非定常雷诺平均 Navier-Stokes 求解器。CSD 求解器是一种通用的多体动力学求解器，能够对几何非线性梁和壳单元进行建模。CFD/CSD 结果能够捕捉空气动力和机翼变形的整体趋势。尽管升力的预测和测量变化相似，但耦合的气动弹性求解器往往低估了阻力大小。耦合 CFD/CSD 求解器用于评估机翼灵活性对机翼性能的影响。结果表明，在特定情况下，降低机翼刚度会增加时间平均空气动力升力和升力比。机翼刚度降低导致前缘涡环流强度降低。这表明机翼性能的提高主要是由于机翼柔顺性增加所允许的合力矢量的重定向。结果表明，在特定情况下，降低机翼刚度会增加时间平均空气动力升力和升力比。机翼刚度降低导致前缘涡环流强度降低。这表明机翼性能的提高主要是由于机翼柔顺性增加所允许的合力矢量的重定向。结果表明，在特定情况下，降低机翼刚度会增加时间平均空气动力升力和升力比。机翼刚度降低导致前缘涡流强度降低。这表明机翼性能的提高主要是由于机翼柔顺性增加所允许的合力矢量的重定向。