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Holographic interferometry as a tool for visualization of temperature fields in fluids
Dančová, Petra ; Vít, Tomáš ; Lédl, V. ; Trávníček, Zdeněk ; Doleček, R.
Measurement of temperature field in moving fluids is connected with many difficulties. Usage of point temperature measurement methods, such as Constant Current Anemometry (CCA), is limited to frequencies up to 3kHz. This frequency should be the limiting factor for using the CCA in fluid when fast change of temperature occurs. This shortcoming of CCA measurements should be overcome by using of optical methods such as digital holographic interferometry. It is necessary to employ a special holographic setup with double sensitivity instead of the commonly used Mach-Zehnder type of holographic interferometer in order to attain the parameters sufficient for the studied case. This setup is not light efficient like the Mach-Zehnder type but has double sensitivity. The special technique of acquiring and phase averaging of results from holographic interferometry is presented.
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Termoakustický prime mover – demonstrace a prvotní experimenty
Chen, Y.-Ch. ; Vít, Tomáš ; Lédl, V. ; Kordík, Jozef ; Maršík, František ; Wang, A. B. ; Doleček, R. ; Trávníček, Zdeněk
The present paper focuses on an experimental investigation of the thermoacoustic prime mover (sound generator), which was designed with the quarter-wave resonant tube. The working fluid was air under the barometric pressure. This study proves function of the prime mover, and demonstrates variety of experimental methods for experimental investigation of the thermoacoustics: acoustic measurements (the resonant frequency, power spectrum, and sound pressure level), temperature measurement (temperatures along the resonant tube, namely near the thermoacoustic stack), hot-wire measurement (oscillation velocities and displacements), and optical experiments by the holographic interferometry.
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Optical methods in experimental mechanics
Hrabovský, Miroslav
The paper deals with experimental methods used in experimental mechanics, especially in experimental stress analysis. High attention is given to optical methods - classical and modern optical methods and its future in mechanics. They are classical interferometry based on optical interference and superposition, stereometry, photoplasticity, moiré, holography speckle photography etc.
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