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Realisation of the full potential of the laser doppler anemometer in the analysis of complex flows

Published online by Cambridge University Press:  04 July 2016

R. V. Barrett  and
C. Swales
R. V. Barrett
Affiliation:
Department of Aerospace EngineeringUniversity of BristolBristol, UK
C. Swales
Affiliation:
Department of Aerospace EngineeringUniversity of BristolBristol, UK
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Abstract

An improved method of alignment for the laser doppler anemometer has been developed which greatly enhances its capabilities for the examination of the often very small scale complexities of three-dimensional flows. Unlike the alignment methods normally employed, which are subjective, this method is quantitative, using a pin-hole device to measure laser light intensity. This ‘pin-hole meter’ also enables the geometry of the laser beam configuration to be defined in situ and with greater facility and precision than previous methods. Examples are given which illustrate the enhanced capability of the system, the greatest improvement coming from the ability to operate in the difficult to achieve and sustain, off-axis mode of signal collection. With this mode, the improved procedures enable very small measurement volumes, typically 50 micron diameter, while maintaining high data rates, in measurements taken from distances compatible with accessing the flow from outside the windtunnel.

Type
Research Article
Information
The Aeronautical Journal , Volume 102 , Issue 1016 , July 1998 , pp. 313 - 320
Copyright
Copyright © Royal Aeronautical Society 1998 

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