摘要
通过在NF-3低速风洞专门研制的翼型模型及相应的俯仰和沉浮振动机构,选用NACA0012翼型进行大迎角下不同频率的振动实验,研究了模型振动平均状态下对其气动力特性的影响情况,并在N-S方程基础上对振动流场进行了初步分析。实验与计算研究的结果表明:在临近定常失速迎角的大迎角条件下,翼型的振动可以引起旋涡分离,导致翼型升力减小和失速迎角的提前;就所讨论的两种振动模式而言,俯仰振动的影响大于沉浮振动。所以,为了提高飞机模型,尤其是大展弦比飞机模型的风洞实验精准度,在模型设计和加工时要特别注意加强机翼弦向的扭转刚度。
NACA0012 airfoil was adopted to carry out the vibration experiment with larger incidences and different frequencies by using model airfoil and pitching vibration and plunging vibration mechanisms specially designed in a NF-3 low-speed wind tunnel. Aerodynamic characteristics of the model airfoil were investigated,and vibration flow field around airfoil at high incidences was preliminarily analyzed based on the solution of unsteady Reynolds-Averaged Navier-Stokes equation. Experimental and numerical results show that airfoil vibration can cause large scale unsteady vortex shedding at larger incidences closing to the steady stall incidence,therefore,lead to lift decreasing and the stall appearance at some lower incidence than steady mean stall incidence。Regarding these two vibration modes,the airfoil＇s pitching effects is more serious than that of plunging. So,in order to improve the wind tunnel experiment accuracy of model plane especially of the model plane with large aspect ratio,the chord torsion stiffness should be stronger in model design.
出处
《实验力学》
CSCD
北大核心
2010年第6期655-660,共6页
Journal of Experimental Mechanics
基金
国家重点实验室基金(9140C4203020705)资助
关键词
俯仰振动机构
沉浮振动机构
N-S方程
升力特性
失速迎角
pitching vibration mechanism
plunging vibration mechanism
Navier-Stokes equation
lift characteristics
stall incidence
