Rotordynamic Forces Developed by Labyrinth Seals

Abstract : The basic laser anemometer system purchased was not the five beam system described in the proposal. The system purchased was recommended by TSI Inc. after the funding was obtained. This system is substantially better than the one originally proposed since it uses three colors for each of the three velocity components instead of two colors and frequency shift. Figure 1 is a schematic of the acquired system. The three color system allows the measurement range of the vertical and on-axis velocity components to be doubled. In addition, the acquired system uses 30 deg off axis back scatter to collect the doppler signal. This results in a better signal to noise ratio in the photomultiplier output and also yields better spatial filtering by the optic system. The intersection of the three different color measurement volumes was reduced in size using this new system. This was especially important for the measurements inside the labyrinth seals. Attached is a listing of the various parts purchased for both the laser anemometer system and for the computer system dedicated to the laser system.