摘要
通过求解非定常Navier-Stokes方程,模拟了风洞实验中模型振动条件下的流场,以翼型振动对流场和气动力的影响为突破口,研究了模型振动对流场、尤其是大迎角流场的影响,并考虑了模型弹性轴不同位置对结果的影响。研究结果表明:在临近传统定常失速迎角的大迎角条件下,翼型的振动可以引起翼型大尺度的分离,导致翼型失速的提前发生,其提前量取决于振动的幅度、频率。风洞模型设计中的弹性轴所处的翼型弦向位置也对结果有一定影响。其研究结果对大展弦比机翼的风洞实验结果分析、模型设计有指导意义。
Based on the solution of unsteady Reynolds-Averaged Navier-Stokes equations, the flow field and aerodynamic characteristics of an airfoil at high incidences are investigated considering the vibration of wind-tunnel models, especially for the wind-tunnel airplane with wings having high aspect ratio. The three vibration modes considered for the airfoil are plunging, pitching and forward-back motions. The phase delay between different vibration modes is also studied. It is shown that the vibration of the airfoil can cause large scale unsteady separated vortex shedding before the stall incidence, thus leading to the occurrence of stall at some lower incidence than the steady meaning stall incidence. Different phase delay has different effect on the flow-field. If the pitching vibration has small phase delay following the plunging vibration, the effect is large. If the amplitudes of vibrations are large enough, the stall incidence may occur more than 2 degrees than the airfoil keeping still.
出处
《工程力学》
EI
CSCD
北大核心
2009年第4期240-245,共6页
Engineering Mechanics
基金
国家自然科学基金项目(10572120,10372085)
