Brian S. Thurow

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A real-time flow visualization system that produces 17 images over a time span of 150 ms is used to visualize the mixing layers of Mach 1.3 (M c50.59) and Mach 2.0 (M c50.87) ideally expanded high Reynolds number axisymmetric jets. These image sequences reveal details about the influence of compressibility on the dynamics of turbulence structures. In(More)
A novel 3-D, 3-C PIV technique is described, based on volume illumination and a plenoptic camera to measure a velocity field. This technique is based on light-field photography, which uses a dense microlens array mounted near a camera sensor to sample the spatial and angular distribution of light entering the camera. Tomographic algorithms (MART) are then(More)
This paper describes current calibration methods for plenoptic cameras and introduces a new method of calibration that seeks to estimate the position and orientation of the microlens array based on the camera geometry and on a calibration image. A geometrical model was formulated to relate the position of a microlens to the location on the image sensor(More)
The recent development of a volumetric PIV system utilizing the unique light-field capturing capabilities of a plenoptic camera is described. The fundamental concept of a plenoptic camera, including a distinction between plenoptic 1.0 and plenoptic 2.0 is given, along with an illustration of the ability to computationally refocus an image after it has been(More)
The application of a novel technique for 3-D visualization of a zero-pressure gradient turbulent boundary layer is discussed. Measurements of a 1.65δ x 1.65δ x 1.65δ volume were taken at a flow speed of 96 ft/s, Reθ ~ 5900, and δ = 1.21 inches in a 2 ft x 2 ft open circuit wind tunnel. Many different mechanisms for flow seeding were explored in order to(More)
A 3-D microphone array was developed and used to locate the origins of individual sound waves that were created within a high-speed and high Reynolds number turbulent jet. In previous work by the authors, a linear array of microphones and simultaneous temporally resolved flow visualizations were used to determine the origin of individual sound waves and(More)
The design and performance of a third-generation megahertz-rate pulse burst laser system is described. The third-generation system incorporates two distinct design changes that distinguish it from earlier-generation systems. The first is that pulse slicing is now achieved by using an economical acousto-optic modulator (AOM), and the second is the use of a(More)
A second-generation pulse-burst laser system for high-speed flow diagnostics is described in detail. The laser can produce a burst of high-energy pulses (of the order of hundreds of millijoules per pulse) with individual pulse durations of less than 10 ns and pulse separations as short as 1 micros. A key improvement is the addition of a phase-conjugate(More)
Light-field cameras in conjunction with computational refocusing can be used to produce volumetric estimates of an imaged scene. However, these estimates are often dominated by image blur in the depth direction from objects not in each synthesized focal plane. Tomographic algorithms have been shown to be effective in creating volumetric estimates from(More)
A high speed 3-D flow visualization system is synchronized with a 2-D particle image velocimetry (PIV) system to simultaneously capture instantaneous 3-D images with a 2-D PIV slice through the center of the measurement volume. Trials were performed on a zero pressure gradient (ZPG) turbulent boundary layer (Reθ ~ 4900) on the wall of a 2 ft x 2 ft open(More)