Effect of Test Rhombus Size on Photon Correlation Laser Velocimeter Data

摘要

This thesis provides an experimental evaluation of the effects of test rhombus size on the photon correlation Laser Velocimeters. It also provides a method and results of laser beam expansion and beam diameter measurements. The study was carried out in the turbulent regime of a plane free jet 1 cm by 10 cm. The flow field measurements were made at 25 jet widths downstream of the nozzle exit, at M = 0.3, using 0.5, 1.0, 1.1, 3.0, 5.0., 7.0 and 10.0 mm diameter laser beams. The measurements taken were mean velocities and turbulence intensities which were then compared with the theoretical predictions and earlier experimental results. The Laser Velocimeter System provided accurate results for mean velocities, but was found to be limited at higher turbulence levels (above 20%) for beam diameters up to and less than 5.0 mm. (Author)