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Book Development Analysis and Application of Laser induced Fluorescence and Rayleigh Scattering Measurement Systems in a Hypersonic Wind Tunnel

Download or read book Development Analysis and Application of Laser induced Fluorescence and Rayleigh Scattering Measurement Systems in a Hypersonic Wind Tunnel written by Charles Tyler and published by . This book was released on 1996 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Application of Advanced Laser Diagnostics to Hypersonic Wind Tunnels and Combustion Systems

Download or read book Application of Advanced Laser Diagnostics to Hypersonic Wind Tunnels and Combustion Systems written by and published by . This book was released on 2009 with total page 45 pages. Available in PDF, EPUB and Kindle. Book excerpt: This LDRD was a Sandia Fellowship that supported Andrea Hsu's PhD research at Texas A & M University and her work as a visitor at Sandia's Combustion Research Facility. The research project at Texas A & M University is concerned with the experimental characterization of hypersonic (Mach>5) flowfields using experimental diagnostics. This effort is part of a Multidisciplinary University Research Initiative (MURI) and is a collaboration between the Chemistry and Aerospace Engineering departments. Hypersonic flight conditions often lead to a non-thermochemical equilibrium (NTE) state of air, where the timescale of reaching a single (equilibrium) Boltzmann temperature is much longer than the timescale of the flow. Certain molecular modes, such as vibrational modes, may be much more excited than the translational or rotational modes of the molecule, leading to thermal-nonequilibrium. A nontrivial amount of energy is therefore contained within the vibrational mode, and this energy cascades into the flow as thermal energy, affecting flow properties through vibrational-vibrational (V-V) and vibrational-translational (V-T) energy exchanges between the flow species. The research is a fundamental experimental study of these NTE systems and involves the application of advanced laser and optical diagnostics towards hypersonic flowfields. The research is broken down into two main categories: the application and adaptation of existing laser and optical techniques towards characterization of NTE, and the development of new molecular tagging velocimetry techniques which have been demonstrated in an underexpanded jet flowfield, but may be extended towards a variety of flowfields. In addition, Andrea's work at Sandia National Labs involved the application of advanced laser diagnostics to flames and turbulent non-reacting jets. These studies included quench-free planar laser-induced fluorescence measurements of nitric oxide (NO) and mixture fraction measurements via Rayleigh scattering.

Book Laser Spectroscopic Measurement Techniques for Hypersonic Turbulent Wind Tunnel Flows

Download or read book Laser Spectroscopic Measurement Techniques for Hypersonic Turbulent Wind Tunnel Flows written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2018-12-29 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: A review is given of the nature, present status, and capabilities of two laser spectroscopic methods for the simultaneous measurement of temperature, density, and their fluctuations owing to turbulence in high speed wind tunnel flows. One method is based on the two frequency excitation of nitric oxide seeded into a nitrogen flow, using tunable dye lasers. The second, more recent method relies on the excitation of oxygen in air flows using a tunable, ArF excimer laser. Signal are obtained from both the laser induced fluorescence and from Raman scattering of the same laser pulse. Measurements are demonstrated in the turbulent boundary layer of a Mach-2 channel flow. Mckenzie, Robert L. and Fletcher, Douglas G. Ames Research Center NASA-TM-103928, A-92076, NAS 1.15:103928 RTOP 505-59-40...

Book Laser Raman Flow field Diagnostics of Two Large Hypersonic Test Facilities

Download or read book Laser Raman Flow field Diagnostics of Two Large Hypersonic Test Facilities written by W. D. Williams and published by . This book was released on 1979 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: Laser-Raman scattering has been utilized to discover nonequilibrium N2 vibrational levels in a continuous, resistance-heated wind tunnel (Tunnel C) and in an arc-heated wind tunnel (Tunnel F). Vibrational temperatures of up to two times the bulk reservoir temperature have been measured in the Tunnel F free stream. A double-diaphragm device for delay of the Tunnel F nozzle expansion was found to significantly reduce the vibrational temperature level. In tunnel C, the vibrational temperatures were found to be dependent upon the water vapor concentration in the flow. It is hypothesized that water vapor-induced de-excitation of the vibrationally excited nitrogen molecules results in a significant rise in local static temperature and corresponding reduction in Mach number. (Author).

Book Development of Filtered Rayleigh Scattering Velocimetry for Wind Tunnel Application

Download or read book Development of Filtered Rayleigh Scattering Velocimetry for Wind Tunnel Application written by C. Carter and published by . This book was released on 1998 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: THIS REPORT DEVELOPED UNDER SBIR CONTRACT The goal of this SBIR program was to develop a FRS (filtered Rayleigh scattering) velocimetry instrument for the study of unsteady flow fields. During Phase I we constructed a single-velocity-component device for use with a single-mode Q-switched Nd:YAG laser. This ERS device included a custom wavemeter for recording accurately the laser wavelength on each pulse, two 16-bit, back-illuminated CCD cameras, and custom Windows-95 software for integrating the wavemeter and cameras. Initially, we tested and debugged the FRS system using a supersonic (Mach 1. 36) axisymmetric jet. These tests demonstrated that accurate mean (within 5%) and instantaneous (within 4%) velocities can be obtained with this technique. Subsequent to these tests, we implemented the FRS velocimetry instrument in the SARL (Subsonic Aerodynamic Research Laboratory) wind tunnel to test the feasibility of applying this advanced instrumentation in a realistic large-scale tunnel facility. We investigated the flow over a delta-wing model with and without tail fins; here, the freestream velocity compared well to the value derived from pitot probes, while FRS measurements over the delta wing provided new insight into complex, unsteady flows. Potential applications include the timely and cost-efficient testing of novel aerodynamic concepts and designs in large-scale wind tunnels.

Book A Method for Measuring Temperatures and Densities in Hypersonic Wind Tunnel Air Flows Using Laser induced O2 Fluorescence

Download or read book A Method for Measuring Temperatures and Densities in Hypersonic Wind Tunnel Air Flows Using Laser induced O2 Fluorescence written by Gabriel Laufer and published by . This book was released on 1990 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Advanced Laser Diagnostics of Compressible Flows

Download or read book Advanced Laser Diagnostics of Compressible Flows written by and published by . This book was released on 2003 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advanced laser diagnostics have been developed to study the fundamentals of supersonic flows for scramjet applications. Filtered Rayleigh scattering and planar laser-induced fluorescence (PLIF) techniques were developed and applied for measuring temperature and species in reacting and nonreacting flows. Fundamental studies of a cavity flame-holder in reacting and nonreacting supersonic flows were conducted. Several cavity-configuration and fueling schemes were employed, and combustion performance was documented. Raman scattering was utilized to measure the time-averaged equivalence ratio of cavity fueling. OH-PLIF was used to mark the reaction zone of the combustion and aid the optimization of fueling. An isolator of rectangular cross section with adjustable divergence angles has been evaluated for different inlet Mach numbers. Shock structures and fluctuations of shock position were also identified at various Mach numbers, divergence angles, and pressure ratios. The potential application of a plasma torch as an alternative ignition source for the scramjet combustor was also investigated through experimental and CFD studies. Maintenance and upgrade of the test facility and support of testing were performed.

Book American Doctoral Dissertations

Download or read book American Doctoral Dissertations written by and published by . This book was released on 1996 with total page 872 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Laser Light Scattering Diagnostic for Measurement of Flow Velocity in Vicinity of Propagating Shock Waves

Download or read book Laser Light Scattering Diagnostic for Measurement of Flow Velocity in Vicinity of Propagating Shock Waves written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-19 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: A laser light scattering diagnostic for measurement of dynamic flow velocity at a point is described. The instrument is being developed for use in the study of propagating shock waves and detonation waves in pulse detonation engines under development at the NASA Glenn Research Center (GRC). The approach uses a Fabry-Perot interferometer to measure the Doppler shift of laser light scattered from small (submicron) particles in the flow. The high-speed detection system required to resolve the transient response as a shock wave crosses the probe volume uses fast response photodetectors, and a PC based data acquisition system. Preliminary results of measurements made in the GRC Mach 4, 10 by 25 cm supersonic wind tunnel are presented. Spontaneous condensation of water vapor in the flow is used as seed. The tunnel is supplied with continuous air flow at up to 45 psia and the flow is exhausted into the GRC laboratory-wide altitude exhaust system at pressures down to 0.3 psia. Seasholtz, Richard G. and Buggele, Alvin E. Glenn Research Center NASA/TM-2002-211503, NAS 1.15:211503, E-13269

Book Measurements of Density Temperature and Their Fluctuations in Turbulent Supersonic Flow Using UV Laser Spectroscopy

Download or read book Measurements of Density Temperature and Their Fluctuations in Turbulent Supersonic Flow Using UV Laser Spectroscopy written by and published by . This book was released on 1992 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nonintrusive measurements of density, temperature, and their turbulent fluctuation levels have been obtained in the boundary layer of an unseeded, Mach 2 wind tunnel flow. The spectroscopic techniques that was used to make the measurements is based on the combination of laser-induced oxygen fluorescence and Raman scattering by oxygen and nitrogen from the same laser pulse. Results from this demonstration experiment are compared with previous measurements obtained in the same facility using conventional probes and an earlier spectroscopic technique. Densities and temperatures measured with the current technique agree with the previous surveys to within 3% and 2%, respectively. The fluctuation amplitudes for both variable agree with the measurements obtained using the earlier spectroscopic technique and show evidence of an unsteady, weak shock wave that perturbs the boundary layer. (Author).

Book On the measurement of flow field properties near the optical window of a hypersonic interceptor by means of laser induced fluorescence spectroscopy

Download or read book On the measurement of flow field properties near the optical window of a hypersonic interceptor by means of laser induced fluorescence spectroscopy written by Kandasamy Vaidyalingam and published by . This book was released on 1995 with total page 41 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Dissertation Abstracts International

Download or read book Dissertation Abstracts International written by and published by . This book was released on 1997 with total page 676 pages. Available in PDF, EPUB and Kindle. Book excerpt: