Laser velocimeter measurement of developing and periodic flows
Abstract
The transmitting-receiving lens system of a two-component backscatter laser-velocimeter optical package currently in operation is discussed. It is basically a Galilean-type telescope which provides for spatial translation of the focal volume along the optical axis, but it also has certain optical constraints which are discussed. This scanning feature of the unit has been used with spectrum analyzer processing for the measurement of (1) trailing vortices in a wind tunnel and (2) a developing (decaying) vortex that was generated by towing a wing model through a water towing tank. The optical system has also been interfaced with period counting electronics and has been applied to the periodic flow generated by a model helicopter rotor. Results are presented and the techniques of data acquisition and the 'strobing' of the processor are discussed.
- Publication:
-
2nd International Workshop on Laser Velocimetry, Volume 2
- Pub Date:
- 1974
- Bibcode:
- 1974lave....2..143O
- Keywords:
-
- Fluid Dynamics;
- Laser Applications;
- Lens Design;
- Velocity Measurement;
- Vortices;
- Wind Tunnel Tests;
- Flow Distribution;
- Helicopter Propeller Drive;
- Optical Equipment;
- Oscillating Flow;
- Periodic Variations;
- Spectrum Analysis;
- Trailing Edges;
- Transmitter Receivers;
- Water Flow;
- Wind Tunnels;
- Instrumentation and Photography