Design of a three dimensional Doppler anemometer for T2 transonic wind tunnel

The design of a three-dimensional laser Doppler anemometer for the T2 wind tunnel which can measure simultaneously and without disturbance the three instantaneous components of the velocity in a complex transonic flow is described. The design is an innovative one, including fiber optics and real-time signal processing, using a digitized Fourier transform. These technologies have been tested and qualified. The complete system allows systematic optical measurements for most experiments performed in the T2.<>