Optical Advances in Laser Transit Anemometry

A Laser Transit Anemometer (LTA) system for measurement of velocity, flow angle and turbulence in the rotating blade rows of turbomachinery and for other applications has been developed by the authors (SDL). Advanced optical, electronic, and computer components make the system sensitive to submicron scatterers, provide automated data collection and permit probing close to blade and wall surfaces, in some cases without seeding the flow. This paper describes new and practical developments of the optical system and presents test results from axial compressor measurements. Based upon these test results, improvements were incorporated into the system and these improvements are discussed briefly.