Download or read book Strategies for Planar Laser induced Fluorescence Thermometry in Shock Tube Flows written by Ji Hyung Yoo and published by Stanford University. This book was released on 2011 with total page 151 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis was motivated by the need to better understand the temperature distribution in shock tube flows, especially in the near-wall flow regions. Two main ideas in planar laser-induced fluorescence (PLIF) diagnostics are explored in this thesis. The first topic is the development of a single-shot PLIF diagnostic technique for quantitative temperature distribution measurement in shock tube flow fields. PLIF is a non-intrusive, laser-based diagnostic technique capable of instantaneously imaging key flow features, such as temperature, pressure, density, and species concentration, by measuring fluorescence signal intensity from laser-excited tracer species. This study performed a comprehensive comparison of florescence tracers and excitation wavelengths to determine the optimal combination for PLIF imaging in shock tube flow applications. Excitation of toluene at 248nm wavelength was determined to be the optimal strategy due to the resulting high temperature sensitivity and fluorescence signal level, compared to other ketone and aromatic tracers at other excitation wavelengths. Sub-atmospheric toluene fluorescence yield data was measured to augment the existing photophysical data necessary for this diagnostic technique. In addition, a new imaging test section was built to allow PLIF imaging in all regions of the shock tube test section, including immediately adjacent to the side and end walls. The signal-to-noise (SNR) and spatial resolution of the PLIF images were optimized using statistical analysis. Temperature field measurements were made with the PLIF diagnostic technique across normal incident and reflected shocks in the shock tube core flow. The resulting images show uniform spatial distribution, and good agreement with conditions calculated from the normal shock jump equations. Temperature measurement uncertainty is about 3.6% at 800K. The diagnostic was also applied to image flow over a wedge. The resulting images capture all the flow features predicted by numerical simulations. The second topic is the development of a quantitative near-wall diagnostic using tracer-based PLIF imaging. Side wall thermal boundary layers and end wall thermal layers are imaged to study the temperature distribution present under constant pressure conditions. The diagnostic technique validated in the shock tube core flow region was further optimized to improve near-wall image quality. The optimization process considered various wall materials, laser sheet orientations, camera collection angles, and optical components to find the configuration that provides the best images. The resulting images have increased resolution (15[Mu]m) and are able to resolve very thin non-uniform near-wall temperature layers (down to 60[Mu]m from the surface). The temperature field and thickness measurements of near-wall shock tube flows under various shock conditions and test gases showed good agreement with boundary layer theory. To conclude this thesis, new applications and future improvements to the developed PLIF diagnostic technique are discussed. These suggested refinements can provide an even more robust and versatile PLIF imaging technique capable of measuring a wider range of flow conditions near walls.
Download or read book Strategies for Planar Laser induced Fluorescence Thermometry in Shock Tube Flows written by Ji Hyung Yoo and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis was motivated by the need to better understand the temperature distribution in shock tube flows, especially in the near-wall flow regions. Two main ideas in planar laser-induced fluorescence (PLIF) diagnostics are explored in this thesis. The first topic is the development of a single-shot PLIF diagnostic technique for quantitative temperature distribution measurement in shock tube flow fields. PLIF is a non-intrusive, laser-based diagnostic technique capable of instantaneously imaging key flow features, such as temperature, pressure, density, and species concentration, by measuring fluorescence signal intensity from laser-excited tracer species. This study performed a comprehensive comparison of florescence tracers and excitation wavelengths to determine the optimal combination for PLIF imaging in shock tube flow applications. Excitation of toluene at 248nm wavelength was determined to be the optimal strategy due to the resulting high temperature sensitivity and fluorescence signal level, compared to other ketone and aromatic tracers at other excitation wavelengths. Sub-atmospheric toluene fluorescence yield data was measured to augment the existing photophysical data necessary for this diagnostic technique. In addition, a new imaging test section was built to allow PLIF imaging in all regions of the shock tube test section, including immediately adjacent to the side and end walls. The signal-to-noise (SNR) and spatial resolution of the PLIF images were optimized using statistical analysis. Temperature field measurements were made with the PLIF diagnostic technique across normal incident and reflected shocks in the shock tube core flow. The resulting images show uniform spatial distribution, and good agreement with conditions calculated from the normal shock jump equations. Temperature measurement uncertainty is about 3.6% at 800K. The diagnostic was also applied to image flow over a wedge. The resulting images capture all the flow features predicted by numerical simulations. The second topic is the development of a quantitative near-wall diagnostic using tracer-based PLIF imaging. Side wall thermal boundary layers and end wall thermal layers are imaged to study the temperature distribution present under constant pressure conditions. The diagnostic technique validated in the shock tube core flow region was further optimized to improve near-wall image quality. The optimization process considered various wall materials, laser sheet orientations, camera collection angles, and optical components to find the configuration that provides the best images. The resulting images have increased resolution (15[Mu]m) and are able to resolve very thin non-uniform near-wall temperature layers (down to 60[Mu]m from the surface). The temperature field and thickness measurements of near-wall shock tube flows under various shock conditions and test gases showed good agreement with boundary layer theory. To conclude this thesis, new applications and future improvements to the developed PLIF diagnostic technique are discussed. These suggested refinements can provide an even more robust and versatile PLIF imaging technique capable of measuring a wider range of flow conditions near walls.
Download or read book Shocktube Planar Laser Induced Fluorescence Measurements in Support of the AEDC Impulse Facility written by and published by . This book was released on 1994 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper describes the status of a program underway at AEDC to develop the Planar Laser Induced Fluorescence (PLIF) method of measurement of temperature and number density for use in the AEDC Impulse Shock Tunnel Facility. The technique is being developed in a laboratory shocktube environment which economically provides repeatable, well-characterized flow fields. A laboratory of this type is critical for the demonstration, validation, and calibration of facility diagnostics systems. PLIF nitric oxide images in shocktube flows for selected incident Mach numbers between Ms = 2.0 and 2.5 and temperatures between 1,000 and 1,500 K for spherical, 30-deg half-angle cone, and 10-deg half-angle blunt cone model geometries are presented. PLIF nitric oxide images of the flow field around a 10-deg half-angle blunt cone recorded during initial runs of the Impulse Facility are shown. Emission spectroscopy measurements in the nose cone bowshock region of the model in the AEDC Impulse Facility flow field are reported.
Download or read book Planar Laser induced Fluorescence Imaging of Velocity and Temperature in Shock Tunnel Free Jet Flow written by J. L. Palmer and published by . This book was released on 1992 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Annual Research Briefs written by Center for Turbulence Research (U.S.) and published by . This book was released on 2011 with total page 434 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Emission Spectroscopy and Planar Laser induced Fluorescence of Nitric Oxide for Shock Tube and Tunnel Studies written by Amberyn Thomas and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Laser induced Fluorescence Thermometry of Reacting Flows written by Dana Ray Coldren and published by . This book was released on 1990 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book International Aerospace Abstracts written by and published by . This book was released on 1999 with total page 1016 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Temperature Measurements in Gases Using Planar Laser induced Fluorescence Imaging of NO and O2 written by Michael Poliang Lee and published by . This book was released on 1991 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt: Three techniques based on Planar Laser-Induced Fluorescence (PLIF) have been developed for the measurement of 2-D temperature fields in gaseous flows. The methods are applicable to a wide range of aerodynamic and combustion flows.
Download or read book 21st AIAA Advanced Measurement and Ground Testing Technology Conference 00 2528 00 2700 written by and published by . This book was released on 2000 with total page 446 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Acetone Planar Laser induced Fluorescence and Phosphorescence for Mixing Studies of Multiphase Flows at High Pressure and Temperature written by Thao T. Tran and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book AIAA Journal written by American Institute of Aeronautics and Astronautics and published by . This book was released on 2003 with total page 938 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Single pulse Gas Thermometry at Low Temperatures Using Two photon Laser induced Fluorescence in NO N2 Mixtures written by and published by . This book was released on 1983 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Processing Techniques for Flow Images Obtained by Planar Laser induced Fluorescence written by Adrian Jon Ferrier and published by . This book was released on 1991 with total page 462 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Visualisation and Instantaneous Planar Laser induced Fluorescence Imaging Techniques Developed and Applied to Turbulent Flows written by Jodie Simone Fox and published by . This book was released on 2003 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental Assessment and Enhancement of Planar Laser Induced Fluorescence Measurements of Nitric Oxide in an Inverse Diffusion Flame written by and published by . This book was released on 1997 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1991 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt:
