Techniques for Optical Interferanemography.
Abstract
The suitability of available anemometry and interferometry systems for forming an optical interfranemography system has been evaluated. It was determined that a three-dimensional laser Doppler interferometer (LDA) should be able to provide the spatial and velocity resolution required. All standard interferometric systems measure the integrated index variation along the line of sight. Consequently, they do not provide spatial resolution and are only adequate in systems that are symmetric along the line of sight. If spatial resolution is required, a tomographic system can be used but the optical access required exceeds that commonly available in wind tunnels. To overcome these shortcomings a new interferometric technique was searched for. It was found that the Lau interferometer could be modified so that measurements were made in a restricted volume. The interferometer that was assembled and tested operated in a shearing mode. The system used a white light source, yielding a bright image, and the system is able to withstand severe vibrations without degrading the signal. The Lau interferometer has been examined in detail and the theory of operation is presented. Keywords: Optical interferanemography Laser Doppler anemometry; Lau interferometry; and flow diagnostics.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1985
- Accession Number
- ADA165950
Entities
People
- A. J. Lightman
- S. Cartwright
Organizations
- University of Dayton