共轴刚性旋翼悬停流场的PIV风洞试验研究

使用粒子图像测速(Particle image velocity,PIV)技术对2 m直径共轴刚性旋翼悬停流场进行了风洞试验研究。在所搭建的共轴刚性旋翼试验台上,对1 100 r/min和1 860 r/min两种转速,8°和10°两种总距下的共轴刚性旋翼流场进行了测量,并测量了单独上旋翼相同状态下的流场。通过对试验数据进行处理,得到了不同状态下桨尖涡的脱落轨迹以及流场速度矢量图。同时通过对比分析,研究了共轴刚性旋翼之间的气动干扰现象,并指出了上旋翼桨尖涡尾迹通过下旋翼桨盘时的"二次收缩"效应。

Experimental Study of Rigid Coaxial Rotor Flowfield in Hovering StateBased on PIV Technique

The flowfield of ?2 m rigid coaxial rotor in hovering state were measured in wind tunnel based on particle image velocity (PIV) technique. The test condition with rotational speeds of 1 100 r/min and 1 860 r/min, collective pitches of 8° and 10° were measured on the test rigid coaxial rotor stand. Meanwhile, the isolate upper rotor under the same condition were measured for comparison. The trajectory of tip vortex and the distribution of velocity vector were obtained. Furthermore, the aerodynamic interaction between the upper rotor and the lower rotor were investigated, and the "secondary contraction effect" of the vortex wake of the upper rotor was observed when it passed through the disk of the lower rotor.