Download or read book Characteristics of Hydrogen Combustion in a Direct Injected Constant Volume Combustion Chamber Using Rainbow Schlieren Deflectometry written by Tanisha Latrina Booker and published by . This book was released on 2011 with total page 229 pages. Available in PDF, EPUB and Kindle. Book excerpt: The nation's need for alternative fuels for Internal Combustion Engines (ICEs) has been a major concern for automotive researchers. The need for a sustainable energy system has lead researchers to consider alternative fuels such as hydrogen and thus, several studies have been conducted on this fuel since the 1930s. In particular, understanding the combustion performance of hydrogen at varying equivalence ratios, ignition timings, and volumetric percentages with other fuels is necessary to optimize engine operations. This study investigates the combustion performance of hydrogen injected into a constant volume combustion chamber (CVCC). The properties studied include flame structure, combustion duration, flame front speed, chamber pressure, and net heat transfer rate. The fuel was injected directly into the chamber containing quiescent air at atmospheric pressure. An ignition system consisting of a coil and a spark plug was used to ignite fuel/air mixtures. This study implemented an optical technique, Rainbow Schlieren Deflectometry, to visualize fuel jet penetration, turbulent fuel-air mixing, flame structure, and flame propagation. Schlieren images were analyzed by a cross-correlation technique to compute flame front speed. A dynamic pressure sensor was used to acquire instantaneous chamber pressures which were used to estimate transient chamber net heat transfer rates. First, experiments were conducted by varying the fuel supply pressure to the chamber and the overall equivalence ratio. An investigation of the fuel jet penetration showed that it takes the fuel jet 2.25 ms to reach the igniter. This result was helpful in establishing ignition times for later experiments. Results showed that fuel supply pressure does not affect fuel jet penetration. The fuel jet, however, creates turbulence in the chamber that affects combustion processes. The equivalence ratios tested were [phi] = 1.0, 0.804, and 0.318. Results showed that equivalence ratio has a significant impact on flame front speed which decreased as the equivalence ratio decreased. Next, experiments were conducted to study the effects of ignition time on combustion processes. A programmable logic controller was added to the experimental setup to control ignition time and aid in sequencing events. The ignition times tested were t = 3, 5, and 10 ms in the early ignition group, t = 20, 30, and 40 ms in the mid-ignition group, and t = 60, 80, 240, and 540 ms in the late ignition group, where t = 0 refers to the start of fuel injection. Ignition time affects the flame structure and flame propagation. Results showed that at ignition times prior to the close of the fuel injector, the initial flame front speed is high because of fuel-jet generated turbulence. After the fuel injector closes, increasing the ignition time increases the combustion duration because of dissipating fuel-jet generated turbulence. Ignition time also has significant effects on chamber pressure variations and net heat transfer rates. Next, the effect of ignition time for varying equivalence ratios was studied. Experiments were conducted at three equivalence ratios, [phi] = 0.6, 0.8, and 1.0 and four ignition times, t = 3 ms, 10 ms, tend, and tend + 50 ms. An ultra-high speed camera was incorporated into the experimental setup to acquire schlieren images at a frame rate of 50,000 Hz and exposure time of 19.8μs. Results show that equivalence ratio has minor effects on chamber pressure variations and net heat transfer rate at early ignition times and on flame structure and flame propagation at any ignition times. Ignition time has a significant effect on all combustion processes. Finally, experiments were conducted to determine the effect of hydrogen percentages by volume on methane combustion at varying ignition times. A second high pressure injector was incorporated into the experimental setup to inject the methane into the combustion chamber. Experiments were conducted at the following methane/hydrogen percentages: 23% CH4 - 77% H2, 33% CH4 - 67% H2, 43% CH4 - 57% H2, 53% CH4 - 47% H2, and 63% CH4 - 37% H2. The two ignition times were t = tend and t = tend + 50 ms. Results show that combustion duration decreases as hydrogen percentage increases for identical ignition times, and as ignition time decreases at identical hydrogen percentages. Flame front speed increases as hydrogen percentage increases. Peak chamber pressure and peak net heat transfer rate decreases for the late ignition time at fixed hydrogen percentages.
Download or read book Survey of Hydrogen Combustion Properties written by Isadore L. Drell and published by . This book was released on 1957 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt: This literature survey digest of hydrogen-air combustion fundamentals presents data on flame temperature, burning velocity, quenching distance, flammability limits, ignition energy, flame stability, detonation, spontaneous ignition, and explosion limits. The data are assessed, recommended values are given, and relations among various combustion properties are discussed. New material presented includes: theoretical treatment of variation in spontaneous ignition lag with temperature, pressure, and composition, based on reaction kinetics of hydrogen-air composition range for 0.01 to 100 atmospheres and initial temperatures of 0 degrees to 1400 degrees k.
Download or read book Study of Hydrogen Gas jet Deffusion Flames Using High Speed Rainbow Schlieren Deflectometry System written by Tommy Sing Hu Wong and published by . This book was released on 2004 with total page 378 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Emission Spectra from High pressure Hydrogen oxygen Combustion written by Marshall C. Burrows and published by . This book was released on 1962 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Computational Study of the Chemical Kinetics of Hydrogen Combustion written by T. L. Burks and published by . This book was released on 1981 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt: A set of elementary reactions and their corresponding rate coefficients has been assembled to describe the homogeneous H2-O2 reaction system over the temperature range 300-3000 K. The reaction mechanism was drawn together assuming that H2-O2 reactive mixtures could be adequately described in terms of self-consistent, thermal distributions of electronically neutral, ground-state reactants, intermediates and products. The resulting time-dependent ordinary differential equations describing the system were integrated assuming various initial pressures, temperatures and initial concentrations of reactants and diluents. The computed results have been compared with experimentally observed induction times, second explosion limits, the rate of reaction above the second explosion limit and the temporal behavior of reaction species. The good agreement between the computational and experimental results attests to the accuracy of the assembled mechanism in its description of the homogeneous reaction system and supports the validity of the set of associated rate coefficients for the elementary reactions of the mechanism over a broad range of reaction conditions. (Author).
Download or read book Scaling of Buoyancy Effects in Hydrogen Gas jet Diffusion Flames Using Rainbow Schlieren Deflectometry written by Steven M. Cherry and published by . This book was released on 1997 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Large Scale Separate Effects Tests on Hydrogen Combustion during Direct Containment Heating Events written by Meyer, Leonhard and published by KIT Scientific Publishing. This book was released on 2014-04-22 with total page 78 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Analytic Solutions to the Ignition Kinetics of the Hydrogen oxygen Reaction written by Richard S. Brokaw and published by . This book was released on 1964 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental and Numerical Study of Dynamics of Premixed Hydrogen Air Flames Propagating in Ducts written by Huahua Xiao and published by Springer. This book was released on 2015-11-03 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis offers important new insights into and a deeper understanding of premixed flame instabilities and hydrogen safety. Further, it explains the underlying mechanisms that control the combustion processes in tubes. The author’s previous scientific accomplishments, which include a series of high-quality publications in the best journals in our field, Combustion and Flame and International Journal of Heat and Mass Transfer, are very impressive and have already made a significant contribution to combustion science.
Download or read book Gaseous Combustion at Constant Volume written by William Shelor Young and published by . This book was released on 1939 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Characteristics of Combustion Pressure Vibration in Hydrogen Fuel Injection Hot Surface Ignition Engines written by M. Takiguchi and published by . This book was released on 1987 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Specific Heat Ratios and Isentropic Exponents For Constant Volume Combustion of Stoichiometric Mixtures of Hydrogen Oxygen Diluted With Helium Or Hydrogen written by Canada. Defence Research Board and published by . This book was released on 1965 with total page 35 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Specific Heat Ratios and Isentropic Exponents For Constant Volume Combustion of Stoichiometric Mixtures of Hydrogen Oxygen Diluted With Helium Or Hydrogen written by André Benoît and published by . This book was released on 1967 with total page 21 pages. Available in PDF, EPUB and Kindle. Book excerpt: The document is complementary to AD-455 747, 'Thermodynamic and Composition Data for Constant-Volume Combustion of Stoichiometric Mixtures of Hydrogen-Oxygen Diluted with Helium or Hydrogen', by A. Benoit. It includes the calculation of the equilibrium specific heats, the equilibrium specific heat ratios, the isentropic exponents, and the corresponding values of the speeds of sound. For convenience, the final-to-initial temperature ratio and the final-to-initial pressure ratio are also included in the tables. The results are presented for helium and hydrogen dilution respectively. (Author).
Download or read book Quantitative Rainbow Schlieren Deflectometry As a Temperature Diagnostic for Spherical Flames written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-21 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: Numerical analysis and experimental results are presented to define a method for quantitatively measuring the temperature distribution of a spherical diffusion flame using Rainbow Schlieren Deflectometry in microgravity. First, a numerical analysis is completed to show the method can suitably determine temperature in the presence of spatially varying species composition. Also, a numerical forward-backward inversion calculation is presented to illustrate the types of calculations and deflections to be encountered. Lastly, a normal gravity demonstration of temperature measurement in an axisymmetric laminar, diffusion flame using Rainbow Schlieren deflectometry is presented. The method employed in this paper illustrates the necessary steps for the preliminary design of a Schlieren system. The largest deflections for the normal gravity flame considered in this paper are 7.4 x 10(-4) radians which can be accurately measured with 2 meter focal length collimating and decollimating optics. The experimental uncertainty of deflection is less than 5 x 10(-5) radians. Feikema, Douglas A. Glenn Research Center NASA/TM-2004-212955, AIAA Paper 2004-0958, E-14351-1
Download or read book A Study of Turbulent Nonpremixed Hydrogen Combustion with Different Levels of Modelling and Computation written by Prasad V. R. K. S. Pokkunuri and published by . This book was released on 2007 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Gaseous Combustion at Constant Volume Burning Velocities of Hydrogen air and Ethylen air Mixtures as Functions of Temperature and Pressure a Dissertation William Shelor Young written by William Shelor Young and published by . This book was released on 1939 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Gaseous Combustion at Constant Volume Burning Velocities of Hydrogen air and Ethylene air Mixtures as Functions of Temperature and Pressure a Dissertation Presented for the Degree of Doctor of Philosophy William Shelor Young written by William Shelor Young and published by . This book was released on 1939 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
