Thesis (Ph.D.) -- McMaster University, 1997. / Includes bibliographical references (p. 234-241). Also available via World Wide Web.

Thesis (Ph. D.)--Missouri University of Science and Technology, 2008. / Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed August 21, 2008) Includes bibliographical references.

Thesis (doctoral)--Lund University, 1998. / Added t.p. with thesis statement inserted. Includes bibliographical references.

Thesis (doctoral)--Lund University, 1998. / Added t.p. with thesis statement inserted. Includes bibliographical references.

Thesis (Ph. D.)--Institute of Paper Science and Technology, Georgia Institute of Technology, 2003.

No description available.

A laser Doppler Anemometer (LDA) is used to make Reynolds stress measurements in a fully developed, turbulent pipe flow. Traverses are made to measure shear stress, normal stresses, and the correlation coefficient. To assess the accuracy of this system, these measurements are compared with results from other published investigations. The differences between the published reports are discussed to emphasize how much turbulence measurements can vary, even in a well-studied flow. Descriptions are included about LDA theory and turbulence measurement techniques. The techniques discussed include the selection of proper sampling rate, the reduction of statistical bias, the choice of amplification, and optimization practices. / Master of Science

A rapidly scanning directionally sensitive three-velocity-component laser Doppler velocimeter (RSLDV) has been designed. It permits scans through three-dimensional flows to obtain space-time velocity information and almost "instantaneous" velocity profiles vital to understanding such flows. A flexible optical system allows for easy variation of the fringe spacing as well as the location and size of the measurement volume. Several optical techniques to maintain coincidence between the horizontal, U and W, and vertical, V, probe volumes were investigated. A lens, used like a prism, and two plane mirrors for the out of plane scanning laser beam maintains good coincidence between the probe volumes, while maintaining some flexibility. Moving fringe patterns in the horizontal and vertical planes are produced by two solid state Bragg cells. The Doppler frequency is independent of the position of the receiving optics, and only one photomultiplier tube (PMT) is needed to receive the signals for all three velocity components. A data acquisition, control and processing system has also been designed for use with the RSLDV. The PMT signal and location of the measurement volume are recorded simultaneously by two transient recorders. The system provides storage for up to 1.25 gigabytes (6 secs.) of LDV data, with permanent storage onto optical disk. A 20 MFLOP array processor provides for fast computation of velocity information. The Pisarenko harmonic decomposition (PHD) and fast Fourier transform (FFT) algorithms, with various interpolation techniques, were investigated for processing low signal-to-noise ratio signals for use with the RSLDV. The PHD algorithm was found to be unsuitable for use with processing RSLDV signals, however, the algorithm does provide superior frequency estimation for some frequency ratios at SNR levels above 30 dB, which are typical quality signals required for frequency counters. The FFT with zero-padding and log parabolic fit provides frequency estimates with RMS error below 1 % for signals with SNR above -5 dB. To obtain frequency estimates for signals with SNR below -5 dB, the FFT with zero-padding and parabolic lit must be used, signals with SNR down to -18 dB can be processed with this technique. / Master of Science / incomplete_metadata

A three-color, three-component Laser Doppler Anemometer (LOA) capable of making simultaneous measurements of three components of velocity is described, and the use of this LOA to measure three non-orthogonal velocity components in the rotor blade passage of a single-stage axial-flow compressor is reported. Measurements were made at four radial locations from 50% span out to the blade tip, and at seven different axial locations from -0.55 axial chord 1.40 axial chord. Measurements were made at only one throttle setting. The measured velocities are used to determine the flow in the orthogonal axial - tangential - radial, x - t - r, coordinate system of the compressor. Although the mean velocities and entire Reynolds stress tensor are obtained with this system, only the mean velocities are reported. Results are presented in the form of a series of vector plots showing: 1.) the primary flow as projected on the x - t plane and 2.) the secondary flow in the t - r plane. The LOA measurements are shown to agree with pitot probe measurements in the stationary frame and basic secondary flow theory. A detailed error analysis is presented, taking into account both measurement uncertainties and statistical biasing. An analysis is also made of particle lag in the rotating flow of the compressor blade passage. A discussion of the difficulties encountered in making three dimensional velocity measurements in turbomachinery blade passages is presented. Suggestions are made for improving the present system for this task. / Master of Science

A novel, point measurement, proof-of-concept laser velocimeter has been developed and tested. The diode array velocimeter (DAV) uses a single laser beam for its probe. The DAV measures velocity within a seeded, transparent medium by timing the passage of a seed particle’s image across an array of PIN photodiodes. This prototype device can measure one component of mean velocity as well as one component of time-averaged turbulence intensity. The concept for the DAV is rather simple. It also has an advantage over existing laser velocimeters in that it is relatively inexpensive. Measurements made with the prototype DAV are compared to those made by a single hot-wire anemometer in a turbulent wall bounded flow with a freestream velocity of 10 m/s. The prototype DAV was found to be accurate to within 10% of U_e in mean velocity, and within 1.5% of U_e in turbulence intensity. The prototype DAV can measure mean velocities as great as 60 m/s. It has the potential for making measurements in highly turbulent reversing flows. / Master of Science