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Seeing in with X-rays: 4D Strain and Thermometry Measurements for Thermal-Mechanical Testing

Winters, C.; Jones, E.M.C.; Halls, Benjamin R.; Murray, Shannon E.; Miers, John C.; Westphal, Eric R.; Hansen, Linda E.; Lowry, Daniel R.; Fayad, S.S.; Obenauf, Dayna G.; Vogel, Dayton J.; Quintana, Enrico C.; Davis, Seth M.; Ramirez, Abraham J.; Jauregui, Luis; Roper, Christopher M.

Understanding temperature-dependent material decomposition and structural deformation induced by combined thermal-mechanical environments is critical for safety qualification of hardware under accident scenarios. Seeing in with X-rays elucidated the physics necessary to develop X-ray strain and thermometry diagnostics for use in optically opaque environments. Two parallel thermometry schemes were explored: X-ray fluorescence and X-ray diffraction of inorganic doped ceramics– colloquially known as thermographic phosphors. Two parallel surface strain techniques–Path-Integrated Digital Image Correlation and Frequency Multiplexed Digital Image Correlation–were demonstrated. Finally, preliminary demonstration of time-resolved digital volume correlation was performed by taking advantage of limited view reconstruction techniques. Additionally, research into blended ceramic-metal coatings was critical to generating intrinsic thermographic patterns for the future combination of X-ray strain and thermometry measurements.

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Bubble Behavior in a Vertically Vibrating Enclosed, Liquid-Filled Cylinder

AIAA Journal

Obenauf, Dayna G.; Halls, Benjamin R.; Torczynski, John R.

When subjected to certain harmonic oscillations, the gas bubble in a partially liquid-filled, closed, vertical cylinder will break up. Under certain conditions, some of the gas will migrate to the bottom due to Bjerknes forces. At sufficiently large amplitudes, the bubble will break up into gas bubbles at the top and bottom ends of the cylinder. High-speed imaging captured the dynamics of bubble breakup and gas migration. Several parameters were investigated: oscillation frequency, oscillation acceleration, gas volume fraction, and liquid viscosity.

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6 Results
6 Results