THE FUNDAMENTALLY EXPERIMENTAL RESEARCH ON MEASURING COMPLICATED FLOW FIELD USING THE ULTRASONIC-LASER METHOD
复杂流场的超声—激光测量原理研究

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.