Laser Doppler velocimetry using polarization-preserving optical fibers for simultaneous measurement of multidimensional velocity components

Laser Doppler velocimeter (LDV) systems using polarization-preserving optical fibers are developed by the polarization and the color methods for simultaneous measurement of multidimensional velocity components. By the use of fibers the construction of the optical systems are made easy, the systems are made more flexible, and remote measurement is realized. A signal processor for the LDVs is developed using only a single frequency counter, a high-speed electronic scanner, and a computer. Using Karman vortex flow and turbulent premixed flame, it is demonstrated that these systems are powerful tools for fluid mechanic measurements.