Download or read book Exploration of Shock droplet Ignition and Combustion written by John Patten and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Liquid fuels are desirable in aerospace applications due to their higher energy density when compared to gaseous fuels. With the advent of detonation-based engines, it is necessary to characterize and analyze how liquid fuel interacts with detonation waves as well as shocks to ignite. While liquid fuel sprays have been proven to successfully aid and sustain detonations, the physical mechanism by which the individual liquid droplets accomplish this is yet to be understood. Such knowledge allows for more predictable detonation properties, which in turn can let detonation-based engines be sustained more easily. This research seeks to quantify and characterize interactions of liquid fuels with detonations and shocks, analyzing the breakup mechanism as well as the ignition of select fuels. Such effects will be characterized for several different mixture compositions as well as shock and detonation speeds. Primary analysis techniques include shadowgraph, Schlieren, and chemiluminescence imaging. Data on pressure will also be taken with pressure transducers to confirm shock and detonation properties. This research will further the progress of liquid fuel detonation-based engines by enabling more predictable and sustainable detonations.
Download or read book Ignition of Powdered Fuels Behind Shock Waves written by A. A. Borisov and published by . This book was released on 1968 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ignition and combustion behind a reflected shock wave of particles stirred up from a layer of finely divided fuel by a passing shock wave have been studied experimentally. It is noted that the results of this study may be of interest for the study of the kinetics of heterogeneous combustion reactions. The fuel used was charcoal, brush carbon, or black powder. The data indicate that the fuels ignite behind shock waves at M = 2.25 and above with different ignition delays. The minimum ignition temperature was about 900K for the carbons and 800K for black powder. Pressure oscillographs showed that pressure behind the reflected shock front at the end of the tube remains constant for about 1.5 msec, then increases for 6-8 msec.
Download or read book Shock Tube Study of the Ignition and Combustion of Aluminum written by J. F. Driscoll and published by . This book was released on 1983 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt: The goal of this project is to obtain data that will help identify the reaction mechanism and the ignition limits of aluminum at elevated temperatures and pressures. Formidable problems arise when attempting such measurements in rocket motors since conditions are unsteady and not easy to control. Therefore, it was decided to mount a pure aluminum sample to the end wall of a shock tube and to ignite the sample using a reflected shock wave. The pressures and temperatures that can be achieved (40 atm, 5000 K) are typical of rocket motor conditions and are much higher than those obtained in previous studies using incident shock waves in conventional shock tubes. The aluminum sample reacts with a test gas in which the proportions of nitrogen, hydrogen, oxygen and chlorine are the same as found in ammonium perchlorate.
Download or read book Dynamics of Shock Waves Explosions and Detonations written by J. Raymond Bowen and published by . This book was released on 1984 with total page 632 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Auto ignition Behavior of Hydrocarbons Behind Reflected Shock Waves written by Derk Jan Vermeer and published by . This book was released on 1970 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Shock Wave Science and Technology Reference Library Vol 4 written by F. Zhang and published by Springer Science & Business Media. This book was released on 2009-06-12 with total page 407 pages. Available in PDF, EPUB and Kindle. Book excerpt: The fourth of several volumes on solids in this series, the six extensive chapters here are more specifically concerned with detonation and shock compression waves in reactive heterogeneous media, including mixtures of solid, liquid and gas phases.
Download or read book Modeling the Influence of Shock Waves on the Combustion of Aluminum Droplets written by Ryan Houim and published by . This book was released on 2011 with total page 296 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Characterization of an Aerosol Shock Tube Facility for Heterogeneous Combustion Studies written by Lori Marie Sandberg and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Combustion is responsible for providing energy for many applications, especially in propulsion and rocket propellants. Shock tubes provide a controlled, repeatable means of studying combustion characteristics; although, most of these studies require the fuel in a mixture to exist in pure gas-phase. This makes it challenging to test low-vapor-pressure fuels that tend to remain in condensed form. Low-vapor-pressure fuels are commonly used in many combustion applications, making combustion studies of these fuels important. A method to study low-vapor-pressure fuels using a shock tube approach is to inject the fuel into the shock tube as tiny, uniformly-sized aerosol droplets. The sub-micron-sized aerosol droplets remain uniformly suspended in the shock tube prior to running the experiment. An incident shock wave vaporizes the liquid fuel droplets, then the reflected shock wave initiates ignition of the mixture. This study presents the characterization of an aerosol fuel injection method to the shock tube to study the combustion of low-vapor-pressure fuels. An aerosol generator was used to produce repeatable, uniformly-sized fuel droplets, and flow controllers were used to control and measure oxygen and argon dilution gas injected into the shock tube. A technique was developed to ensure consistent and repeatable aerosol fuel production rates over which calibration curves were found. This study presents the ignition delay times for C7H16 ([phi] = 1.0) at a pressure of 2.0 atm for temperatures from 1220 - 1427 K, C7H8 ([phi] = 1.0) at 1.9 atm over a temperature range of 1406 - 1791 K, and C12H26 ([phi] = 0.3) at 3.0 atm for the temperature range of 1293 - 1455 K. The ignition delay times for heptane and toluene were compared to the literature values at the same conditions and were found to be in good agreement. Laser extinction (visible laser at 632nm) was used to verify the presence of aerosol fuel droplets inside the shock tube for dodecane, but showed the heptane aerosol vaporized upon injection into the shock tube. Initial laser absorption (3.39 [mu]m) measurements were also taken. This aerosol technique was found to successfully evaluate combustion effects of low-vapor-pressure fuels; however, was limited by the range of possible fuel concentrations. Further work needs to be performed on the verification of aerosol spatial uniformity and obtaining higher fuel concentrations. The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/149475
Download or read book Shock Wave Focusing Phenomena in Combustible Mixtures written by Hans Grönig and published by . This book was released on 2000 with total page 101 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Shock Tube Techniques for Fuel Droplet Combustion Studies written by F. Jaarsma and published by . This book was released on 1967 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advanced Turbulent Combustion Physics and Applications written by N. Swaminathan and published by Cambridge University Press. This book was released on 2022-01-06 with total page 485 pages. Available in PDF, EPUB and Kindle. Book excerpt: Explore a thorough overview of the current knowledge, developments and outstanding challenges in turbulent combustion and application.
Download or read book Ignition of Fuel Droplets in Hot Stagnant Gases written by Gordon Alfred Long and published by . This book was released on 1967 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ignition of SiH H 0 N behind Reflected Shock Waves written by Allen G. McLain and published by . This book was released on 1983 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Development and Application of Aerosol Shock Tube Methods for the Study of Low vapor pressure Fuels written by Daniel Robert Haylett and published by Stanford University. This book was released on 2011 with total page 169 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis describes a new facility and method of experimentation, which can be used to study the combustion chemistry of low-volatility fuels in the gas phase. Two main goals are described: first, the development of the aerosol shock tube and procedures; and second, a demonstration of its capabilities. There is a lack of high-quality, accurate chemical kinetics data for the oxidation of large hydrocarbons, which are important for modeling diesel, rocket, or jet engines among other combustion systems. While conventional shock tubes are very effective reactor vessels for low-molecular-weight gaseous fuels (n-alkanes up to five carbon atoms), larger fuel molecules exist as low-volatility liquids/solids, and the vapor-pressures of these fuels are not large enough for high or even moderate fuel loadings. Heating the shock tube has extended the use of shock tubes to carbon numbers of 10 to 12, but beyond that, the high temperatures prior to the shock initiation can decompose the fuel, and (for fuel mixtures like diesel) can cause fractional distillation. The question is then: how can we study low-vapor-pressure fuels in a shock tube? The solution presented here, which avoids the problems associated with heating, is called the aerosol shock tube. In the aerosol shock tube, the fuel is injected as an aerosol of micron-size droplets. Then a series of shock waves first evaporate the fuel and subsequently raise the resultant purely gas-phase mixture to combustion-relevant temperatures. With proper selection of the shock strength and timing, this process effectively decouples the mass and heat transfer processes associated with evaporation from the chemical mechanism of combustion. This enables the study of extremely low-volatility fuels, never before studied in a purely gas-phase form in a shock tube. The first application of this new facility was to measure the ignition delay time for many previously inaccessible fuels in the gas-phase. In this thesis, we have measured ignition delay times for the pure surrogate fuel components n-decane, n-dodecane, n-hexadecane, and methyl decanoate as well as for multi-component fuels such as JP-7 and multiple different blends of diesel fuel. Taken over a range of conditions, these measurements provide sensitive validation targets for their respective chemical mechanisms. These data showed agreement with past heated shock tube experiments for fuels in which premature fuel decomposition is not an issue (n-decane and low concentration n-dodecane). However, when comparing heated and aerosol shock tube ignition delay times for fuels that require significant heating, like n-hexadecane, the existing heated shock tube data demonstrated evidence of premature decomposition. The second application to the study of chemical kinetics was to measure the concentration of important species during the decomposition and oxidation of select low-vapor-pressure fuels. These species time-histories provide much more information for kinetic mechanism refinement. Experiments were performed to measure the important OH radical and the stable intermediate C2H4 for both n-hexadecane and diesel. The number of important low-vapor-pressure fuels that require high-quality validation targets is large, and our new method for providing this data has proven very effective. This work enables the development of the next generation of accurate chemical mechanisms and will be essential to their success.
Download or read book Development of an Aerosol Loading Technique for Ignition Time Measurements in Shock Tubes written by and published by . This book was released on 2007 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt: We have developed a new aerosol loading technique to be used in shock tube measurements of combustion kinetics, in particular ignition times, of low-vapor pressure fuels. This technique provides a uniform spatial distribution of aerosol in the shock tube, which ensures well-behaved shock-induced flows and a narrow micron-sized aerosol size distribution that rapidly evaporates, thereby providing the capability to produce high-concentration vapor mixtures derived from a wide variety of fluids including low-vapor-pressure practical fuels and fuel surrogates. At present we utilize the incident shock wave to vaporize the fuel droplets, and the reflected shock wave to induce chemical reaction. We report here the first aerosol shock tube ignition delay time measurements of n-dodecane/O2/argon mixtures. These measurements are found to be consistent with those made in our heated shock tube facility.
Download or read book Droplet Ignition as an Indicator of Combustion Knock written by E. M. Goodger and published by . This book was released on 1980 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ignition written by John Drury Clark and published by Rutgers University Press. This book was released on 2018-05-23 with total page 217 pages. Available in PDF, EPUB and Kindle. Book excerpt: This newly reissued debut book in the Rutgers University Press Classics Imprint is the story of the search for a rocket propellant which could be trusted to take man into space. This search was a hazardous enterprise carried out by rival labs who worked against the known laws of nature, with no guarantee of success or safety. Acclaimed scientist and sci-fi author John Drury Clark writes with irreverent and eyewitness immediacy about the development of the explosive fuels strong enough to negate the relentless restraints of gravity. The resulting volume is as much a memoir as a work of history, sharing a behind-the-scenes view of an enterprise which eventually took men to the moon, missiles to the planets, and satellites to outer space. A classic work in the history of science, and described as “a good book on rocket stuff…that’s a really fun one” by SpaceX founder Elon Musk, readers will want to get their hands on this influential classic, available for the first time in decades.
