Download or read book Spontaneous Raman Scattering Diagnostics for High pressure Gaseous Flames written by Jun Kojima and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Laser Raman Gas Diagnostics written by Marshall Lapp and published by Springer Science & Business Media. This book was released on 2013-03-14 with total page 387 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Laser Raman Workshop on the r"eas urement of Gas Properti es i sone of aseries of occasional meetings organized in an informal workshop format through the stimulation of Project SQUID, Office of Naval Research. This workshop is the second to be organized on gas-phase applications of Raman scattering. Both Raman workshops were supported by Project SQUID, ONR, and the Air Force Aero Propulsion Laboratory, Wright-Patterson Air Force Base. The first Raman Workshop was held at the AVCO Everett Research Laboratory, Everett, Massachusetts, with their co-sponsorship in January 1972 under the chairmanship of D. A. Leonard. The present meeting was co-sponsored by the General Electric Research and Development Center, and held at their facility in Schenectady, New York. We are grateful to Project SQUID, AFAPL, and GE for their generous financial support of this Workshop, and to Project SQUID for underwriting the publication costs of the Proceedings. As is always the case for successful meetings, many people contributed substantially to the organization and execution of this workshop. Professor Robert Goulard supported, aided, and encouraged us in the most helpful ways, and we are indebted to him. We received further valuable support and assistance from Dr. Ralph Roberts, Director, and Mr. James R. Patton, Jr., of the Power Branch, Office of Naval Research; from Dr. William H. Heiser, Chief Scientist of the Aero Propulsion Laboratory; and from Dr. James M.

Download or read book Development of a High Pressure Gaseous Burner for Calibrating Optical Diagnostic Techniques written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-20 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this work-in-progress report, we show the development of a unique high-pressure burner facility (up to 60 atm) that provides steady, reproducible premixed flames with high precision, while having the capability to use multiple fuel/oxidizer combinations. The highpressure facility has four optical access ports for applying different laser diagnostic techniques and will provide a standard reference flame for the development of a spectroscopic database in high-pressure/temperature conditions. Spontaneous Raman scattering (SRS) was the first diagnostic applied, and was used to successfully probe premixed hydrogen-air flames generated in the facility using a novel multi-jet micro-premixed array burner element. The SRS spectral data include contributions from H2, N2, O2, and H2O and were collected over a wide range of equivalence ratios ranging from 0.16 to 4.9 at an initial pressure of 10-atm via a spatially resolved point SRS measurement with a high-performance optical system. Temperatures in fuel-lean to stoichiometric conditions were determined from the ratio of the Stokes to anti-Stokes scattering of the Q-branch of N2, and those in fuel-rich conditions via the rotational temperature of H2. The SRS derived temperatures using both techniques were consistent and indicated that the flame temperature was approximately 500 K below that predicted by adiabatic equilibrium, indicating a large amount of heat-loss at the measurement zone. The integrated vibrational SRS signals show that SRS provides quantitative number density data in high-pressure H2-air flames. Kojima, Jun and Nguyen, Quang-Viet Glenn Research Center NASA/TM-2003-212738, E-14263

Download or read book Thermometry in High Pressure Gases Using Spontaneous Raman Scattering written by Timothy William Haller and published by . This book was released on 2021 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt: Spontaneous Raman scattering from nitrogen is studied in high pressure gases. Collision frequency increases with increasing gas density, causing spectral lines to broaden due to pressure broadening and mix when the lines are strongly overlapped. Because spontaneous Raman thermometry is accomplished by fitting a simulated spectrum to an experimental spectrum, spectral models that neglect these collision-induced effects will lead to erroneous temperature inference. This work investigates the influence of high density on ro-vibrational spontaneous Raman scattering, which must be understood to obtain accurate thermometry in high pressure gases. The temperature profile through a flame front was measured at 1 atm, 3 atm, and 5 atm using spontaneous Raman scattering from nitrogen. The pressure broadening was measured for the anisotropic tensor component of spontaneous Raman scattering from room temperature nitrogen over the pressure range of 10 atm to 70 atm for three gas compositions: pure nitrogen, air, and nitrogen in argon. The unmixed line model was found to give good fits to the O and S branches for all pressures, which indicates that line mixing effects are not significant in the O and S branches over this pressure range. Using indirect experimental evidence, line mixing effects in the anisotropic component of the Q branch were inferred to be below the threshold set by the experimental spectral resolution at pressures up to 70 atm at room temperature. Assuming that the anisotropic Q branch lines mix like the isotropic lines was found to result in a small systematic error in the inferred temperature at flame temperatures, with the error increasing slowly with pressure. The bias can be removed by modeling the anisotropic spectrum separately from the isotropic spectrum. Line mixing effects should be included in the modeling of the isotropic component of the Raman spectrum, but can probably be neglected in the anisotropic component of the ro-vibrational spontaneous Raman spectrum of nitrogen

Download or read book Development of a High Pressure Gaseous Burner for Calibrating Optical Diagnostic Techniques written by Jun Kojima and published by BiblioGov. This book was released on 2013-07 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this work-in-progress report, we show the development of a unique high-pressure burner facility (up to 60 atm) that provides steady, reproducible premixed flames with high precision, while having the capability to use multiple fuel/oxidizer combinations. The highpressure facility has four optical access ports for applying different laser diagnostic techniques and will provide a standard reference flame for the development of a spectroscopic database in high-pressure/temperature conditions. Spontaneous Raman scattering (SRS) was the first diagnostic applied, and was used to successfully probe premixed hydrogen-air flames generated in the facility using a novel multi-jet micro-premixed array burner element. The SRS spectral data include contributions from H2, N2, O2, and H2O and were collected over a wide range of equivalence ratios ranging from 0.16 to 4.9 at an initial pressure of 10-atm via a spatially resolved point SRS measurement with a high-performance optical system. Temperatures in fuel-lean to stoichiometric conditions were determined from the ratio of the Stokes to anti-Stokes scattering of the Q-branch of N2, and those in fuel-rich conditions via the rotational temperature of H2. The SRS derived temperatures using both techniques were consistent and indicated that the flame temperature was approximately 500 K below that predicted by adiabatic equilibrium, indicating a large amount of heat-loss at the measurement zone. The integrated vibrational SRS signals show that SRS provides quantitative number density data in high-pressure H2-air flames.

Download or read book Measurement and Simulation of Spontaneous Raman Scattering Spectra in High Pressure Fuel Rich H2 Air Flames written by Nasa Technical Reports Server (Ntrs) and published by BiblioGov. This book was released on 2013-08 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: Rotational vibrational spontaneous Raman spectra (SRS) of H2, N2, and H2O have been measured in H2-air flames at pressures up to 30 atm as a first stem towards establishing a comprehensive Raman spectral database for temperatures and species in high-pressure combustion. A newly developed high-pressure burner facility provides steady, reproducible flames with a high degree of flow precision. We have obtained an initial set of measurements that indicate the spectra are of sufficient quality in terms of spectral resolution, wavelength coverage, and signal-to-noise ratio for use in future reference standards. The fully resolved Stokes and anti-Stokes shifted SRS spectra were collected in the visible wavelength range (400-700 nm) using pulse-stretched 532 nm excitation and a non-intensified CCD spectrograph with a high-speed shutter. Reasonable temperatures were determined via the intensity distribution of rotational H2 lines at stoichiometry and fuel-rich conditions. Theoretical Raman spectra of H2 were computed using a semi-classical harmonic-oscillator model with recent pressure broadening data and were compared with experimental results. The data and simulation indicated that high-J rotational lines of H2 might interfere with the N2 vibrational Q-branch lines, and this could lead to errors in N2-Raman thermometry based on the line-fitting method. From a comparison of N2 Q-branch spectra in lean H2 low-pressure (1.2 atm) and high-pressure (30 atm) flames, we found no significant line-narrowing or -broadening effects at the current spectrometer resolution of 0.04 nm.

Download or read book Quantitative Analysis of Spectral Interference of Spontaneous Raman Scattering in High Pressure Fuel Rich H2 Air Combustion written by Nasa Technical Reports Server (Ntrs) and published by BiblioGov. This book was released on 2013-08 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a theoretical study of the spectral interferences in the spontaneous Raman scattering spectra of major combustion products in 30-atm fuel-rich hydrogen-air flames. An effective methodology is introduced to choose an appropriate line-shape model for simulating Raman spectra in high-pressure combustion environments. The Voigt profile with the additive approximation assumption was found to provide a reasonable model of the spectral line shape for the present analysis. The rotational/vibrational Raman spectra of H2, N2, and H2O were calculated using an anharmonic-oscillator model using the latest collisional broadening coefficients. The calculated spectra were validated with data obtained in a 10-atm fuel-rich H2-air flame and showed excellent agreement. Our quantitative spectral analysis for equivalence ratios ranging from 1.5 to 5.0 revealed substantial amounts of spectral cross-talk between the rotational H2 lines and the N2 O-/Q-branch; and between the vibrational H2O(0,3) line and the vibrational H2O spectrum. We also address the temperature dependence of the spectral cross-talk and extend our analysis to include a cross-talk compensation technique that removes the nterference arising from the H2 Raman spectra onto the N2, or H2O spectra.

Download or read book Advanced Diagnostics in Combustion Science written by Zhen-Yu Tian and published by Springer Nature. This book was released on 2023-07-12 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt: This textbook, supported by the Textbook Publishing Center of University of Chinese Academy of Sciences, provides a fundamental introduction to advanced diagnostics techniques for graduate students majoring in combustion science, chemistry, and chemical engineering-related subjects. The textbook provides an overview with respect to the spectroscopic methods in advanced diagnostics techniques such as gas chromatography/mass spectrometry, thermochemical analysis, Raman scattering, and nuclear magnetic resonance. It then describes the comprehensive basic theory, equipment structure, and testing methods of diagnostic techniques and summarizes the analysis methods commonly used in combustion chemical reaction processes. This can provide graduate students with important guidance and comprehensive understanding of diagnostics techniques before performing physics and chemistry experiments. In addition, it provides an introduction into using common mathematical and graphics packages for students to acquire and practice the tools to comply with international standards. The textbook is concise and illustrative and includes hot issues and current progress of diagnostics. In addition, exercises and questions are included at the end of each chapter for students to practice and gain hands-on experience. Given its scope, the textbook is of great benefit to graduate students in combustion chemistry and engineering and other related areas such as environmental science, optical engineering, and thermal science and is also beneficial for researchers with interdisciplinary backgrounds.

Download or read book Combustion Diagnostics Using Laser Spontaneous Raman Scattering written by Perry Pappas Yaney and published by . This book was released on 1979 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt: An existing computer-controlled Raman Spectroscopy system, using a pulsed nitrogen laser and a double spectrometer, was upgraded and used to measure the temperatures in the combustion plume of an afterburning J85-5 turbojet engine. The computer-fitted temperatures had standard deviations between one and three percent. The agreement with simultaneous and sequential gas-sampling probe measurements and with sequential thermocouple measurements was within five percent. Upon completion of these studies, the system was extensively modified for use with a 10-inch diameter combustion tunnel. Forty-eight sets of Raman data were taken over a wide range of operating conditions of the tunnel. The temperatures ranged from 1000 to over 2000 K using methane fuel. The turbulent diffusion flame was characterized by an unsteady appearance and was orange-yellow in color. Poisson standard deviations for 21 of the measurements averaged four percent. Measurements and spectra of the laser-induced and non-laser-induced backgrounds were also obtained and analyzed. (Author).

Download or read book Research Technology 2002 written by and published by DIANE Publishing. This book was released on with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Characterization of High Temperature Vapors and Gases written by John W. Hastie and published by . This book was released on 1979 with total page 836 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Laser Raman Gas Diagnostics written by Marshall Lapp and published by . This book was released on 2014-01-15 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Raman Spectroscopy of Gases and Liquids written by A. Weber and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 327 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Raman effect is a most useful tool for the study of molecular vibrations and molecular structure. Information about the structure and symmetry of molecules, as well as about their vibrational energies can be obtained to a reasonable degree of satisfaction from their infrared and Raman vibrational spectra. The body of knowl edqe of the vibrational infrared and Raman spectra of molecules is immense and is now so well organized and understood that it is found to be represented in any stan dard upper level undergraduate curriculum in chemistry. The rotational energies of a molecule and quantitative details about its structure can only be obtained through the techniques of microwave, and high-resolution infrared and Raman spectroscopy of low pressure gases and vapors. The results of such investigations are of interest . not only to the academic scientists, but also to scientists and engineers who are active in applied fields of chemistry and physics, as well as the atmospheric sciences. This book deals with basic investigations of the Raman scattering of light by gases, with some attention also being given to liquid substances. After a brief in troductory chapter that delineates the historical development of Raman spectroscopy of gases, high-resolution rotation-vibrational and pure rotational Raman spectros copy is described in Chapters 2 and 3. The all-important intensity parameter, the Raman scattering cross section, is treated in Chapter 4, while the broadening of Raman lines due to the effects of intermolecular forces is taken up in Chapter 5.

Download or read book Research Technology 2004 written by and published by DIANE Publishing. This book was released on with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Laser Diagnostics for Combustion Temperature and Species written by Alan C. Eckbreth and published by CRC Press. This book was released on 1996-10-10 with total page 636 pages. Available in PDF, EPUB and Kindle. Book excerpt: Focusing on spectroscopically-based, spatially-precise, laser techniques for temperature and chemical composition measurements in reacting and non-reacting flows, this book makes these powerful and important new tools in combustion research

Download or read book Rotational and Vibrational Raman Spectroscopy for Thermochemistry Measurements in Supersonic Flames written by Alexander C Bayeh and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: High speed chemically reacting flows are important in a variety of aerospace applications, namely ramjets, scramjets, afterburners, and rocket exhausts. To study flame extinction under similar high Mach number conditions, we need access to thermochemistry measurements in supersonic environments. In the current work a two-stage miniaturized combustor has been designed that can produce open supersonic methane-air flames amenable to laser diagnostics. The first stage is a vitiation burner, and was inspired by well-known principles of jet combustors. We explored the salient parameters of operation experimentally, and verified flame holding computationally using a well-stirred reactor model. The second stage of the burner generates an external supersonic flame, operating in premixed and partially premixed modes. The very high Mach numbers present in the supersonic flames should provide a useful test bed for the examination of flame suppression and extinction using laser diagnostics. We also present the development of new line imaging diagnostics for thermochemistry measurements in high speed flows. A novel combination of vibrational and rotational Raman scattering is used to measure major species densities (O2, N2, CH4, H2O,CO2, CO, & H2) and temperature. Temperature is determined by the rotational Raman technique by comparing measured rotational spectra to simulated spectra based on the measured chemical composition. Pressure is calculated from density and temperature measurements through the ideal gas law. The independent assessment of density and temperature allows for measurements in environments where the pressure is not known a priori. In the present study we applied the diagnostics to laboratory scale supersonic air and vitiation jets, and examine the feasibility of such measurements in reacting supersonic flames. Results of full thermochemistry were obtained for the air and vitiation jets that reveal the expected structure of an under-expanded jet. Centerline traces of density, temperature, and pressure of the air jet agree well with computations, while measurements of chemical composition for the vitiation flow also agree well with predicted equilibrium values. Finally, we apply the new diagnostics to the exhaust of the developed burner, and show the first ever results for density, temperature, and pressure, as well as chemical composition in a supersonic flame. The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/151043

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt: