弹性变形对双座电动飞机模型气动特性的影响

与常规飞机相比,电动飞机在气动布局方面采用了更大的展弦比,在气动力作用下弹性变形更加明显.针对双座电动飞机风洞试验模型,采用计算流体力学/计算固体力学(computational fluid dynamics/computational structural dynamics,CFD/CSD)流固耦合方法分别计算了机翼有无弹性变形的气动力特性,并与面元法和风洞试验结果进行比较.结果表明,受弹性变形影响后升力系数增加,阻力系数减小,相同升力系数下的升阻比几乎没有变化,弹性变形对俯仰力矩系数影响显著,变形后的纵向静安定裕度显著提高.采用面元法计算气动弹性变形的方法计算高效,升力系数误差在10％以内,能满足工程实际应用;CFD/CSD流固耦合计算与风洞试验结果更接近,升力线斜率较风洞试验低7％;变形后的纵向静安定性随迎角有增大趋势,与风洞试验结果一致;弹性变形对机翼扭矩影响较大.

Effect of elastic deformation on aerodynamic characteristics of two-seater electric aircraft model

Compared with conventional aircraft, a larger aspect ratio is adopted by electric aircraft in aerodynamic layout, and the elastic deformation is more obvious under aerodynamic effect. For the wind tunnel test model of two-seat electric aircraft, CFD/CSD fluid-structure coupling method is used to calculate the aerodynamic characteristics of the wing with or without elastic deformation, and the results are compared with panel method and wind tunnel test. The results show that the lift coefficient increases and the drag coefficient decreases under the influence of elastic deformation, the lift-drag ratio under the same lift coefficient hardly changes, the impact of elastic deformation on the pitching moment coefficient is significant, and the longitudinal static stability margin after deformation is significantly improved. The calculating aeroelastic deformation by panel method is efficient, and the error of lift coefficient is within 10%, which can satisfy the practical application of engineering. The CFD/CSD fluid-structure coupling calculation is closer to the wind tunnel test result, and the lift slope is 7% lower than the wind tunnel test. The longitudinal static stability increases with the angle of attack after deformation, which is consistent with the wind tunnel test results. The wing torque is greatly affected by elastic deformation.