High speed optical tomography system for quantitative measurement and visualization of dynamic features in a round jet

Infrared absorption for measurement of hydrocarbon concentration in fuel/air mixtures (MAST-B-LIQUID)

“…5. These are higher than those from McMakin et al [41], Dillmann et al [26], as their studies involved a lot more projections due to the use of CCD cameras as detectors, which was not possible in our case because no CCD camera is available operating at 3.39 lm wavelength. Nevertheless, our spatially averaged error agrees well with the absolute error defined by Ko and Kihm [42], which was about 33% for 45 parallel lines and 5 view angles.…”

The diagnostic study of optical tomography for high-temperature flow fields in the open system

“…Up to now, this technique has been mainly used in the structural visualization for low temperature [1,2], low and high speed complex flow fields [3][4][5], the density measurement [6], as well as the temperature measurement for the flow fields whose temperature is not too high [7]. Until now, it is rarely reported that this technology could be used in the structural visualization, or the temperature and the electron number density measurement for the high-temperature complex flow fields [8].…”

Comparison of reconstruction-algorithm performance for optical-phase tomography of a heated air flow

“…Additional flow images appear in earlier papers. 3,10,11 In the following sections we discuss the optical-phasegradient measurements of the Hartmann sensor and how they are made into tomographic projections, the tomographic reconstruction algorithms and performance metrics used for comparison, and the results for tomographic reconstruction for models similar to our flow-imaging application. We find that the quality of the reconstruction is a function of the complexity of the structure present in the image, the basis functions used in the reconstruction, and the reconstruction algorithm.…”

“…Details regarding the selection of the number of views, reconstruction resolution, speed, and system design are provided in earlier papers. 3,6,9 A brief description of the tomography system pertinent to the present study is provided in the next section.…”

“…2 The Hartmann wavefront sensor system used in our previous experimental studies of a heated air jet provides a measurement of the gradient of the optical phase rather than the phase itself. 3 The gradient data must be integrated to obtain the phase projection inputs to the tomographic reconstruction algorithm, an additional computation that adds to the time it takes to create reconstructions and may spatially redistribute errors in the reconstruction.…”