Heterogeneous Ignition of Metals - Model and Experiment
Spontaneous ignition temperature, ignition temperature, and transition temperature for metal-oxidizing gas system models of solid propellant rocket engine combustion processes
Mellor, A. M.↗
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An evaluation of aft-end ignition for solid propellant rocket motors
Performance evaluation of solid propellant rocket motor ignition to determine igniter design and parameters to avoid overpressurization
Fitch, R. E.↗
Ignition transients in small hypergolic rockets.
Factors influencing rocket ignition pressures and conditions leading to large ignition overpressures, estimating residual propellant in rocket combustor
Juran, W.↗
Shock wave ignition of liquid fuel drops
Combustion processes and ignition criteria in shock wave ignition of liquid fuel drop in oxidizing atmosphere
Kauffman, C. W.↗
Resonance tube ignition of hydrogen-oxygen mixtures
Resonance tube ignition system for hydrogen oxygen engines including ignition limits and pressure and temperature effects
Pavli, A. J.↗
Fluidic Ignition Detection
Ignition sensor, utilizing fluidic oscillator device and its ability to react to flow system's molecular weight and temperature changes, detects propellant ignition. Commercial applications include fields of fire protection equipment and fluidics.
Henry, C. S.↗
Remote control flare stack igniter for combustible gases
Device has been designed and developed for igniting nonrecoverable combustible gases and sustaining combustion of gases evolving from various gas vent stacks. Igniter is superior to existing systems because of simplicity of operation, low cost fabrication, installation, operational and maintainability features, and excellent reliability in all phases of required operations.
Ray, W. L.↗
A High-efficiency, Small, Solid-state Laser for Pyrotechnic Ignition
A completely self-contained, small, neodymium laser has been designed and demonstrated for use in a pyrotechnic ignition system. A nominal 16 J of laser energy (1.06 micron wavelength, 1-ms duration) was achieved in a rectangular 10.5-X 15.1-X 25.4-cm package weighting 5.14 kg. This high energy-to-weight ratio is encouraging for laser applications in which specific energy efficiency (energy per unit weight or volume) is important. The laser design concepts are described, and some results on pyrotechnic ignition are given. Some details on a laser currently under construction, which will be 1/8 the size of the above laser, are included.
Yang, L. C.↗
Spontaneous ignition in afterburner segment tests at an inlet temperature of 1240 K and a pressure of 1 atmosphere with ASTM jet-A fuel
A brief testing program was undertaken to determine if spontaneous ignition and stable combustion could be obtained in a jet engine afterburning operating with an inlet temperature of 1240 K and a pressure of 1 atmosphere with ASTM Jet-A fuel. Spontaneous ignition with 100-percent combustion efficiency and stable burning was obtained using water-cooled fuel spraybars as flameholders.
Schultz, D. F.↗
Development and demonstration of flueric sounding rocket motor ignition
An analytical and experimental program is described which established a flueric rocket motor ignition system concept incorporating a pneumatic match with a simple hand pump as the only energy source. An evaluation was made of this concept to determine the margins of the operating range and capabilities of every component of the system. This evaluation included a determination of power supply requirements, ignitor geometry and alinement, ignitor/propellant interfacing and materials and the effects of ambient temperatures and pressure. It was demonstrated that an operator using a simple hand pump for 30 seconds could ignite BKNO3 at a standoff distance of 100 m (330 ft) with the only connection to the ignitor being a piece of plastic pneumatic tubing.
Marchese, V. P.↗
Mechanism of ignition in shock wave interactions with reactive liquid droplets
A detailed qualitative analysis of the processes leading to the explosive ignition of a reactive liquid droplet that is suspended in a gas-phase oxidizer and subjected to the passage of a shock wave, is presented. The interval of time between shock wave passage and ignition is described by identifying a two-stage process which consists of a period of relative reactive dormancy that is followed by a chemical induction period leading to the thermal explosion of reactant that has been stripped from the liquid drop, vaporized, and mixed with the gas-phase oxidizer. The results of first-order calculations based on this model are presented and compared with experimental data for diethlcyclohexane drops in oxygen.
Pierce, T. H.↗
Theoretical studies of massive stars. I - Evolution of a 15-solar-mass star from the zero-age main sequence to neon ignition
The evolution of a star with mass 15 times that of the sun from the zero-age main sequence to neon ignition has been computed by the Henyey method. The hydrogen-rich envelope and all shell sources were explicitly included in the models. An algorithm has been developed for approximating the results of carbon burning, including the branching ratio for the C-12 + C-12 reaction and taking some secondary reactions into account. Penetration of the convective envelope into the core is found to be unimportant during the stages covered by the models. Energy transfer from the carbon-burning shell to the core by degenerate electron conduction becomes important after the core carbon-burning stage. Neon ignition will occur in a semidegenerate core and will lead to a mild 'flash.' Detailed numerical results are given in an appendix. Continuation of the calculations into later stages and variations with the total mass of the star will be discussed in later papers.
Endal, A. S.↗
Sustained arc ignition system
Circuitry for maintaining an arc or spark across a spark gap for a desired length of time is disclosed. A high voltage, direct current source is connected in series with a secondary winding of a high voltage, stepup transformer or coil and a spark gap such as a spark plug for example. The high voltage source may be on continuously or may be turned on and off by a control circuit such as a solid state switch which is, in turn, responsive to a timing device such as a set of ignition contact points or a magnetic pulse generator operating in synchronism with a spark ignition engine. The timing device also provides signals to a current switching circuit which interrupts, current flow through a primary winding of the high voltage coil at the prescribed time that a spark is desired at the spark gap.
Birchenough, A. G.↗
Ignition of magnesium powders in shock wave induced flows
Ignition of magnesium powders, resulting from an interaction with incident shock wave-induced flows, has been studied. A numerical analysis of particle dynamics and heating is presented and compared with experimental measurements. The induction period is strongly dependent on convective heat transfer and not on chemical reaction rate. Experimentally observed ignition delays were on the order of 100 microns and were inversely dependent on shock strength and initial pressure, directly dependent on particle size and cloud concentration, and independent of oxygen concentration down to 2.3 percent oxygen. Good agreement between experiment and theory was realized.
Fox, T. W.↗
A simple laboratory method for determining ignitability of materials
A simple laboratory method for determining ignitability of materials is described. The apparatus consists of a Mellen high-flux heater capable of producing up to 13 W/sq cm heat flux, a Medtherm water-cooled radiometer for measuring heat flux, a mounting frame to hold all components in proper position, and specimen holders of the type used for the NBS smoke test. Time to ignition at different heat flux levels is recorded. Test results are presented for a variety of materials.
Hilado, C. J.↗
Plasma igniter for internal combustion engine
An igniter for the air/fuel mixture used in the cylinders of an internal combustion engine is described. A conventional spark is used to initiate the discharge of a large amount of energy stored in a capacitor. A high current discharge of the energy in the capacitor switched on by a spark discharge produces a plasma and a magnetic field. The resultant combined electromagnetic current and magnetic field force accelerates the plasma deep into the combustion chamber thereby providing an improved ignition of the air/fuel mixture in the chamber.
Fitzgerald, D. J.↗
Kinetics of hydrogen-oxygen and methane-oxygen ignition sensitized by NO or NO2
In a study of methane ignition sensitized by NO2, the induction period chemical kinetics were examined by monitoring reactants and intermediates (CH4, NO2, OH, NO, CO, CO2, and H2O) prior to ignition. Data were obtained at pressure of 2-4 atm, temperatures of 1300-1900 K, equivalence ratios of 0.5-1.0, and NO2 up to 3.4 mole %. A tentative NO2 sensitization mechanism was deduced from the analysis of photometric observations and the comparison of computer modeling with observations.
Slack, M. W.↗
Combustion and operating characteristics of spark-ignition engines
The spark-ignition engine turbulent flame propagation process was investigated. Then, using a spark-ignition engine cycle simulation and combustion model, the impact of turbocharging and heat transfer variations or engine power, efficiency, and NO sub x emissions was examined.
Heywood, J. B.↗