复杂流场的超声-激光测量原理研究

本文从复杂流场—旋涡场参量的超声—激光测试方法的需要出发,论述了超声波产生的声相位光栅对激光产生的偏转效应.并研制了适用于产生空气超声相位光栅的大功率高频超声换能器、位移灵敏接收器、数字相位差测定仪等设备,采用了超声发射的匹配技术等,从而获得了明显的空气超声-激光偏转效应,并且测定了两光束的偏转时间差.本文的结果为利用超声-激光的空气声光偏转效应测量空气旋涡流场参量提供了实验依据.

THE FUNDAMENTALLY EXPERIMENTAL RESEARCH ON MEASURING COMPLICATED FLOW FIELD USING THE ULTRASONIC-LASER METHOD

The properties of deflection of laser beam caused by the acoustic phase grating in fluid is described.The experiment of acousto-optical deflection in water has been done.A high power,high frequency air ultrasonic transducer used to generate air ultrasonic phase grating is fabricated.The ultrasonic laser acousto-optical deflection in air has been observed clearly by using a displacementsensitive detector.A particularly prepared acoustic coupler is set up at a proper place in front of the acoustic radiating surface of the transducer to increase the interference of acoustic field and to decrease the divergence angle of acoustic radiation.The deflected time difference between two laser beams has been measured using a phase-sensitive meter.It can be applied to measure the parameters of the air vortex flow field in wind tunnel test.The basic is set up for the nondestructive measurment of air flow field with ultrasonic-laser method.