大展弦比机翼几何非线性颤振风洞试验研究

目的研究大展弦比机翼在飞行过程中,由于大变形造成几何非线性效应带来的几何非线性颤振问题。方法针对几何非线性颤振问题,设计相应的风洞试验模型,并完成不同变形下的颤振风洞试验,对机翼不同变形下的试验结果进行比较,摸清其几何非线性颤振特性。结果在几何非线性的影响下,机翼的颤振速度随着变形的增大而下降,并且发散模态及颤振频率都发生改变,大变形下的颤振速压下降到小变形时的71.7%。结论在研究大柔性、大展弦比机翼的气动弹性特性时,必须考虑几何非线性效应的影响,否则其颤振特性结论会存在较大的误差。

Geometrical Nonlinear Flutter Research of a High-aspect-ratio Wing through Wind Tunnel Test

Objective To research geometrical nonlinear flutter problem induced by geometrical nonlinear effects because of large structure deformation of high-aspect-ratio wing during flying. Method A wind tunnel test model corresponding to the ge-ometrical nonlinear flutter problem was designed to carry out wind tunnel test under different wing deformations, compare the test results and get the geometrical nonlinear flutter characteristics. Results Under the influences of geometrical nonlinear, the flutter speed was decreased with the increase of deformation. The divergency mode and flutter frequency were also changed because of the influence of geometrical nonlinear. In large deformation, flutter speed was decreased to 71.7 percent of small deformation. Conclusion When the aeroelastic character of high-aspect-ratio flexible wing is analyzed, the influence of geometrical nonlinear must be considered; otherwise it will cause large error for the conclusions of flutter character.