| An Investigation into the Hypergolicity of Dicyanamide-based Ionic Liquid Fuels with Common Oxidizers (Preprint) |
Dec-2008 |
11 pages |
| Authors:
E Dambach; S Heister; I Ismail; S Schneider; T Hawkins; PURDUE UNIV LAFAYETTE IN
|
 | Previous studies have demonstrated that substituted imidazolium dicyanamides are hypergolic with nitric acid. An investigation was conducted to study the hypergolicity of selected dicyanamides, commercially available 1-butyl-3-methyl-imidazolium dicyanamide and Air Force Research Laboratory developed AF-IL-617, with common oxidizers. Diluents, particularly water and methanol, were introduced to the fuel in an effort to understand the effect on the ignition delay. The water dilution limit at which ignition would still occur was ... |
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| Shock Tube Measurements of Ignition Processes and Spray-Shock Wave Interactions |
06 APR 2008 |
26 pages |
| Authors:
Ronald K. Hanson; David F. Davidson; STANFORD UNIV CA DEPT OF MECHANICAL ENGINEERING
|
| We report results of high-temperature shock tube research aimed at improving knowledge of the combustion behavior of diesel, jet and related fuels. Research was conducted in four Stanford shock tube facilities and focused on the following topics: (1) development of the aerosol shock tube; (2) ignition delay time measurements of gaseous jet fuels (JP-8 and Jet-A) and surrogate components at high pressures and low temperatures; (3) laser absorption measurements of ... |
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| Reactive Shear Layer Mixing and Growth Rate Effects on Afterburning Properties for Axisymetric Rocket Engine Plumes |
SEP 2006 |
179 pages |
| Authors:
Carl R. Hartsfield; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| A semi-empirical model was developed for predicting the afterburning ignition location of film cooled rocket engines. The model is based on two characteristic distances, the distance required for turbulent mixing to generate a combustible mixture with the reactive film layer and the distance traveled during the ignition delay. The mixing length is affected by the mass flow, composition of the film cooling layer and the fuel-rich air to fuel ratio ... |
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| Cycle Performance of a Pulse Detonation Engine with Supercritical Fuel Injection |
23 MAR 2006 |
188 pages |
| Authors:
Timothy M. Helfrich; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
|
| Pulse detonation engines (PDE) rely on rapid ignition and formation of detonation waves. Because hydrocarbon fuels are composed typically of long carbon chains that must be reduced in the combustion process, it would be beneficial to create such reduction prior to injection of fuel into the engine. This study focused on PDE operation enhancements using dual detonation tube, concentric-counter-flow heat exchangers to elevate the fuel temperature up to supercritical temperatures. ... |
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| Reduced Chemical Kinetic Mechanisms for Hydrocarbon Fuels |
2006 |
36 pages |
| Authors:
Christopher J. Montgomery; Marc A. Cremer; Jyh-Yuan Chen; Charles K. Westbrook; Lourdes Q. Maurice; REACTION ENGINEERING INTERNATIONAL SALT LAKE CITY UT
|
| Several reduced chemical kinetic mechanisms for combustion of ethylene and n-heptane have been generated using CARM (Computer Aided Reduction Method), a computer program that automates the mechanism-reduction process. The method uses a set of input test problems to rank species by the error introduced by assuming they are in quasi-steady state. The reduced mechanisms have been compared to detailed chemistry calculations in simple homogeneous reactors and experiments. Reduced mechanisms for ... |
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| Highly Accurate Ignition Delay Apparatus for Hypergolic Fuel Research (PREPRINT) |
26 SEP 2005 |
17 pages |
| Authors:
Angelo J. Alfano; Jeffrey D. Mills; Ghanshyam L. Vaghjiani; AIR FORCE RESEARCH LAB EDWARDS AFB CA SPACE AND MISSILE PROPULSION DIV
|
| The efficient development of hypergolic fuels requires an interdisciplinary approach involving ab initio modeling, synthesis, and experimental physical chemistry. Candidate molecules must exhibit hypergolic ignition delay times that are fast enough to warrant further testing for safety and performance criteria. Hypergolic ignition delay apparatus has been mentioned in the open literature for six decades but accurate, detailed, modern ignition delay hardware that uses inexpensive laboratory building blocks and a minimum ... |
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| Investigation of Transient Plasma Ignition for a Pulse Detonation Engine |
MAR 2005 |
79 pages |
| Authors:
Joel Rodriguez; NAVAL POSTGRADUATE SCHOOL MONTEREY CA DEPT OF MECHANICAL AND ASTRONAUTICAL ENGINEERING
|
| Elimination or reduction of auxiliary oxygen use in Pulse Detonation Engines (PDEs) is necessary if the technology is to compete with existing Ramjet systems. This thesis investigated a Transient Plasma Ignition (TPI) system and found that the technology can at least reduce and may be able to completely remove the auxiliary oxygen requirement of current PDE systems. TPI was tested and compared with a traditional capacitive discharge spark plug system ... |
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| Computationally Based Design and Screening of Hypergolic Multiamines |
DEC 2004 |
9 pages |
| Authors:
Michael J. McQuaid; William H. Stevenson; Darren M. Thompson; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| Seeking to identify structural features of saturated, (all) tertiary, alkyl multiamines (STAMs) that correlate with hypergolic ignition delays, conformers of STAMS whose ignition delays have been measured were established through density functional theory-based calculations. Examined from the standpoint of lone pair/(C-N and C-C) bond orientations, a correlation is suggested. Conformers of 1,3-dimethylimidizolidine (DMIZ), a notional hypergol whose synthesis and testing was originally recommended for other reasons, were therefore characterized. On ... |
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| Generation Characterization and Aerospace Applications of Torch Plasmas |
MAY 2004 |
21 pages |
| Authors:
Spencer P. Kuo; POLYTECHNIC UNIV BROOKLYN NY DEPT OF ELECTRICAL ENGINEERING AND COMPUTER SCIENCE
|
| This basic research effort addressed the physical issues related to the generation of atmospheric pressure plasmas and to the use of "Torch Plasmas" for aerospace applications. The most significant accomplishment has been the development of a plasma torch into an ignition aide for use in scramjet engines. It was shown that such a torch can deliver sufficient heat to cold, liquid JP-7 fuel injected into a Mach-2 crossflow (having a ... |
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| Energy-Efficient Transient Plasma Ignition and Combustion |
15 APR 2004 |
35 pages |
| Authors:
Martin Gundersen; UNIVERSITY OF SOUTHERN CALIFORNIA LOS ANGELES DEPT OF ELECTRICAL ENGINEERINGAND ELECTROPHYSICS
|
| Transient plasma discharges utilizing short (30 to 100 nsec), spatially distributed streamers energized by pulsed power were investigated as a potential new method for flame ignition. Experimental results showed shorter ignition delay and pressure rise time (typically by a factor of 3 for methane- air mixtures), as well as higher maximum pressure compared to conventional spark ignition. In all cases significant modification of initial combustion chemistry appeared to be occurring, ... |
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| Detonation Branching in a PDE with Liquid Hydrocarbon Fuel |
MAR 2004 |
90 pages |
| Authors:
Kristin L. Panzenhagen; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
|
| A pulse detonation engine (PDE) capitalizes on the large mass flux and pressure rise associated with detonations to create thrust, which is proportional to PDE cycle frequency. This research showed that using a branched detonation as an ignition source, as opposed to standard spark ignition, deposits more energy into the thrust tube head. The increase in energy decreases ignition delay and detonation to deflagration transition (DDT) time. This allows a ... |
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| Ion Dynamics Related to Hypersonics |
02 JAN 2004 |
20 pages |
| Authors:
Stephen R. Leone; Veronica M. Bierbaum; Shuji Kato; COLORADO UNIV AT BOULDER DEPT OF CHEMISTRY AND BIOCHEMISTRY
|
| This research focused on the study of reactivity and dynamics of ion systems with relevance to atmospheric chemistry and combustion processes. The mobility of the fuel ion, t-C4H9(+), was measured drifting in polar and nonpolar atmospheric gases. These measurements were compared to polarization theory and locked dipole estimates as well as to related ion mobility measurements to better understand differences in interaction potentials. unimolecular and bimolecular reactions of the t-C4H9(+) ... |
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| Reactions and Thermochemistry of Alkyl Ions, Cn H2n+1 + (n=1-8), in the Gas Phase |
20 OCT 2003 |
26 pages |
| Authors:
Skip Williams; Thomas M. Miller; W. B. Knighton; Anthony J. Midey; Susan T. Arnold; A. A. Viggiano; Campbell D. Carter; AIR FORCE RESEARCH LAB HANSCOM AFB MA SPACE VEHICLES DIRECTORATE
|
| Our research program focuses on identifying reaction processes important for plasma enhancement of combustion systems. Recommendations for temperature and energy dependencies of key ion-molecule reactions are made based on the laboratory measurements described above. Thermodynamic data such as heat capacity entropy, and enthalpy are not available as a function of temperature for many of the ionic species formed in these reactions and are thus calculated using quantum mechanical methods. The ... |
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| Part I: Effect of Nitric Oxide and Other Diluents on Cold Starting, Combustion Instability, and White Smoke Emissions in Diesel Engines. Part II: autoignition, Combustion Instability and White Smoke Under Transient Conditions With JP-8 |
16 APR 2003 |
73 pages |
| Authors:
Naeim A. Henein; WAYNE STATE UNIV DETROIT MI CENTER FORAUTOMOTIVE RESEARCH
|
| This report covers an investigation aimed at developing electronic control strategies to improve the cold startability of diesel engines for military, dual-use and hybrid electric vehicles. The emphasis is on the analysis the processes that affect the cranking and acceleration modes during starting. The analysis indicated that NO present in the residual and recirculated gases has on effect on the order or the activation energy of the global autoignition reactions. ... |
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| Autoignition, Combustion Instability and White Smoke under Transient Conditions with JP-8 Fuel |
19 JUN 2001 |
4 pages |
| Authors:
Naeim A. Henein; WAYNE STATE UNIV DETROIT MI CENTER FORAUTOMOTIVE RESEARCH
|
| The goal of this project is to reduce the cold starting problems of military and commercial heavy-duty diesel engines, particularly the emission of white smoke. The failure of the autoignition process and/or combustion instability has been found to be the major causes of the cold starting problems. The approach is mainly experimental, supported by detailed analysis of the autoignition process. Models for the ignition delay period are developed considering the ... |
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| Experimental Study of Plasma-Propellant Interactions |
19 JUN 2001 |
4 pages |
| Authors:
Stefan T. Thynell; Thomas A. Litzinger; PENNSYLVANIA STATE UNIV UNIVERSITY PARK DEPT OF MECHANICAL AND NUCLEAR ENGINEERING
|
| The use of a plasma as an ignition source has revealed several attractive benefits over conventional igniter systems, such as a shorter ignition delay, reduced temperature sensitivity of the propellant, better controlled propellant mass generation rates, and reduced susceptibility to anomalous ignition transients. However, the causes of these attractive benefits at a fundamental level are not well understood. To address the issues in this experimental program, different diagnostic tools are ... |
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| Shock Tube Studies of Ram Accelerator Phenomena |
01 SEP 2000 |
12 pages |
| Authors:
R. K. Hanson; STANFORD UNIV CA DEPT OF MECHANICAL ENGINEERING
|
| The report describes research performed at Stanford University to investigate ram accelerator phenomena using expansion tube and shock tube facilities. The program included three coordinated elements: imaging and modeling of oblique detonations and shock-induced combustion in high-speed wedge and blunt body flows; experimental investigations of fuel jets in supersonic combustion; and measurements and modeling of ignition kinetics propulsion fuel mixtures. The objectives of this research ... |
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| Ignition of Isomers of Pentane: An Experimental and Kinetic Modeling Study |
04 AUG 2000 |
9 pages |
| Authors:
M. Ribaucour; R. Minetti; L. R. Sochet; H. J. Curran; W. J. Pitz; C. K. Westbrook; UNIVERSITE DES SCIENCES ET TECHNOLOGIE LILLE (FRANCE)
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| Experiments in a rapid compression machine were used to examine the influences of variations in fuel molecular structure on the autoignition of isomers of pentane. Autoignition of stoichiometric mixtures of the three isomers of pentane were studied at compressed gas initial temperatures between 640 K and 900 K and at precompression pressures of 300 and 400 torr. Numerical simulations of the same experiments were carried out using a detailed chemical ... |
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| Visualization of High-Power Density Diesel Engine Spray and Combustion |
20 DEC 1999 |
292 pages |
| Authors:
M.-c. Lai; N. A. Henein; T.-c. Wang; J.-s. Han; X Xie; WAYNE STATE UNIV DETROIT MI
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| An experimental visualization study of spray and combustion processes under simulated high-power-density diesel (HPD) combustion conditions is carried out. The scope of work includes characterization of high-pressure injection on test rig, macroscopic and microscopic characterization of non-evaporative sprays in atmosphere ambient condition or in pressurized chamber, and direct visualization of spray and combustion processes inside a single-cylinder optically accessible research engine. The results provide very interesting ... |
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| Reduced Chemical Kinetic Mechanisms for Hydrocarbon Fuels |
JUN 1999 |
12 pages |
| Authors:
Christopher J. Montgomery; Marc A. Cremer; Michael P. Heap; Jhy-Yuan Chen; Charles K. Westbrook; Lourdes Q. Maurice; REACTION ENGINEERING INTERNATIONAL SALT LAKE CITY UT
|
| Using CARM (Computer Aided Reduction Method), a computer program that automates the mechanism reduction process, a variety of different reduced chemical kinetic mechanisms for ethylene and n-heptane have been generated. The reduced mechanisms have been compared to detailed chemistry calculations in simple homogeneous reactors and experiments. Reduced mechanisms for combustion of ethylene having as few as 10 species were found to give reasonable agreement with detailed chemistry over a range ... |
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| Sea Water Immersion of Gem II Propellant |
23 MAR 1998 |
8 pages |
| Authors:
C. I. Merrill; J. D. O'Drobinak; AIR FORCE RESEARCH LAB EDWARDS AFB CA
|
| Following the Delta II flight failure on 17 Jan 97, the question of continuing safety for solid propellant that had fallen into the Atlantic ocean arose. With this failure, approximately 200,000 pounds of HTPB solid propellant were released. While large amounts of propellant were consumed in burning fragments and ground impact explosions, considerable amounts of unburned propellant fell onto the land and into the Atlantic ocean. It was quickly found ... |
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| Spontaneous Ignition of Hydrocarbon Fuels at Temperatures in the Range 750 - 1500 K |
1998 |
63 pages |
| Authors:
John Frederick Griffiths; LEEDS UNIV (UNITED KINGDOM)
|
| This report results from a contract tasking The University of Leeds as follows: The contractor will investigate methods for enhancing the initiation of combustion in hydrocarbon fuels as outlined in his proposal submitted in April 1998. |
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| Combustion Diagnostics and Flow Visualization of Hypergolic Combustion and Gelled Mixing Behavior |
19 DEC 1997 |
17 pages |
| Authors:
Douglas A. Feikema; James Smith; ALABAMA UNIV IN HUNTSVILLE RESEARCH ADMINISTRATION
|
| The combustion of Hypergolic bipropellants in missile systems where the oxidizer and fuel are gelled involve important areas of research: ignition time delay, chemical kinetics, atomization, and liquid phase mixing. Measurements of the total ignition time delay for Hydrazine and Red Fuming Nitric Acid (RFNA) and UDMH/RFNA have been accurately measured using a droplet contact technique. The results show the effect of fuel/oxidizer ratio an the total ignition time delay ... |
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| Reduced Chemical-Kinetic Mechanisms for the Dark Zones of Double-Base and Nitramine Gun Propellants |
MAY 97 |
38 pages |
| Authors:
N. Ilincic; K. Seshadri; W. R. Anderson; N. E. Meagher; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| Simplified chemical-kinetic mechanisms were employed to calculate the structure of the dark zones of burning double-base and nitramine propellants. These reduced mechanisms are expected to be useful in interior ballistic calculations. First, skeletal mechanisms comprised of 22 elementary reactions among 15 species and 23 elementary reactions among 17 species were used to calculate dark zone structures for double-base and nitramine propellants, respectively. The skeletal mechanisms were previously extracted from a ... |
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| Fuel Effects on Diesel Combustion Processes |
OCT 96 |
18 pages |
| Authors:
E. Clasen; K. Song; S. Campbell; Kt Rhee; RUTGERS - THE STATE UNIV NEW BRUNSWICK NJ DEPT OF MECHANICAL INDUSTRIAL AND AEROSPACE ENGINEERING
|
| The crank angle locations for the first occurrences of several main combustion events in a Diesel engine were investigated for varied fuel parameters. The events studied include: preflame reactions; premixed flame propagation; start of pressure rise; maximum rate of pressure rise (dp/dt); and peak cylinder pressure. The fuels employed in the study were in two groups: (1) Base fuel-1 and derivatives prepared by mixing it with small doses of a ... |
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| Development of a Reduced Chemical Kinetic Model for Prediction of Preignition Reactivity and Autoignition of Primary Reference Fuels |
23 JUL 96 |
19 pages |
| Authors:
Houliang Li; David L. Miller; Nicholas P. Cernansky; DREXEL UNIV PHILADELPHIA PA
|
| A reduced chemical kinetic model has been developed for the prediction of major oxidation behavior of primary reference fuels (PRF's) in a motored engine, including ignition delay preignition heat release, fuel consumption, CO formation and production of other species classes. This model consists of 29 reactions with 20 active species and was tuned to be applicable for the neat PRF's, 87 PRF and 63 PRF, and at various engine conditions. ... |
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| Ignition and Flame Spreading Susceptibility of Gun Propellants |
30 JUN 96 |
18 pages |
| Authors:
Kenneth K. Kuo; Stefan T. Thynell; PENNSYLVANIA STATE UNIV UNIVERSITY PARK DEPT OF MECHANICAL ENGINEERING
|
| This work represents the results of a series of tests on ignition and flame spreading processes of gun propellants. The overall effort was split into three tasks: (1) partially confined hot fragment conductive ignition (HFCI) characteristics of high energy, low vulnerability (HELOVA) propellants, (2) shock impact studies on HELOVA propellants, and (3) combustion of layered gun propellants. Results indicated that measured and calculated go/no-go ignition boundaries for XM49 and M43 ... |
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| High-Mass Launch Capability Development for the U.S. Army Research Laboratory's 5O-mm High-Pressure Powder Gun (Range 3O9A) |
APR 96 |
97 pages |
| Authors:
Graham F. Silsby; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
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| Documented here are improvements to the 50-mm high-pressure powder gun system in the U.S. Army Research Laboratory's (ARL's) terminal ballistic Range 309A. It was designed for high velocity, achieved by large charge-to-mass (C-M) ratios and a long navel (120 calibers). The goal here was to maximize performance with C-M ratios near 1. This was achieved by a series of incremental improvements to gun and sabot hardware and to priming and ... |
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| Laser Ignition of Propellants in Closed Chambers |
APR 96 |
29 pages |
| Authors:
R. A. Beyer; L. -m. Chang; B. E. Forch; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
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| Preliminary experiments have been performed in the application of laser ignition to solid and liquid propellants in closed chambers. The effect of confinement on ignitability and the ignition of a range of energetic materials are demonstrated. |
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| Enhancement of Semiconductor Bridge Initiators for Ignition of Large- Caliber Ammunition |
JUN 95 |
36 pages |
| Authors:
Stephen L. Howard; Lang-Mann Chang; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| Semiconductor bridge initiators (SCBI) have been proposed as a means of initiating the ballistic cycle in large-caliber ammunition. However, an ignition delay of more than 10 ms for a black powder basepad was not acceptable for multicomponent tank ammunition. Enhancement of the output from the SCBI was needed to reduce the ignition delay to acceptable levels. Early experiments in a small-caliber ammunition simulator suggested that if the energetic igniter material ... |
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| MTBE for Improved Diesel Combustion and Emissions? |
24 SEP 94 |
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| Authors:
Shuichi Kajitani; H. Usisaki; E. Clasen; S. Campbell; K. T. Rhee; RUTGERS - THE STATE UNIV PISCATAWAY NJ
|
 | Reduced emissions from the spark-ignition engine, when fueled by gasoline containing small amounts of MTBE, have led us to explore similar positive results in compression-ignition (CI) engine combustion by adding this oxygenate compound to Diesel fuel. This study was performed in two separate laboratories by employing the respective experimental apparatus. When a pre- chamber type CI engine was operated by using Diesel fuel mixed with several volume portions of MTBE, ... |
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| A Study of Aircraft Post-Crash Fuel Fire Mitigation |
JUN 94 |
38 pages |
| Authors:
D. W. Naegeli; B. R. Wright; D. M. Zallen; SOUTHWEST RESEARCH INST SAN ANTONIO TX BELVOIR FUELS AND LUBRICANTS RESEARCH FACILITY
|
| Extensive research has been conducted on methods of controlling aircraft post-impact fuel fires. Mechanism studies of hydrocarbon fuel ignition and flame propagation have identified feasible approaches to agent selection and dispersal schemes. Selection of agents is closely controlled by guidelines of the Montreal Protocol Agreements and allowable agent manufacturing as specified by the Environmental Protection Agency. Effectiveness of agents has been determined under a variety of laboratory test conditions. Mass ... |
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| Temperature Sensitivity in Artillery Charge Design |
FEB 91 |
51 pages |
| Authors:
Ronald D. Anderson; Robert T. Puhalla; ARMY BALLISTIC RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| Charge design for large-caliber artillery weapons must allow for many factors which can reduce efficiency and safety when these rounds are used in field situations. One of those factors is the temperature sensitivity of the propellant -- the change in performance caused by differing initial charge temperatures in otherwise identical artillery rounds. By comparing computer simulations of interior ballistic calculations, three factors in propellant grain design are explored -- geometry, ... |
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| Effects of Metal Contamination on Hydroxylammonium Nitrate-Based Liquid Monopropellants |
OCT 90 |
|
| Authors:
Cris A. Watson; John D. Knapton; Nathan Boyer; Irvin Stobie; ARMY BALLISTIC RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| A hydroxylammonium-nitrate-based liquid gu n propellant, LGP 1846, was intentionally contaminated with four separate metals and subjected to storage, shock sensitivity, and closed-bomb tests. The metal contaminants used in this study were iron, copper, nickel, and aluminum. The contaminant concentrations for the storage and the sensitivity tests were approximately 25, 75, and 100 ppm. For the closed-bomb tests, a concentration of approximately 100 ppm was used. Results indicated that the ... |
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| A Study of the Radiant Ignition of a Range of Pyrotechnic Materials Using a CO2 Laser |
AUG 90 |
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| Authors:
Leo De Yong; Brian Park; Frank Valenta; MATERIALS RESEARCH LABS ASCOT VALE (AUSTRALIA)
|
| The ignition energy requirements for a range of pyrotechnic compositions of interest in both Australia and the United States have been measured experimentally using a 400 W CO2 laser operating at 10.6 microns. The effects of several physical and chemical variables were determined on the time to ignition and ignition energy. The materials examined include a gasless delay, igniter compositions, a primer composition and a range of colored smoke compositions. ... |
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| Shock Tube Studies of the Ignition of Triethanol Ammonium Nitrate in Nitrous Oxide: Preliminary Results |
JUN 90 |
|
| Authors:
Richard A. Beyer; ARMY BALLISTIC RESEARCH LAB ABERDEEN PROVING GROUND MD
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| Triethanol ammonium nitrate (TEAN) has been shown to ignite and burn with significant light emission and pressure generation in a nitrous oxide/argon mixture heated in a shock tube. Ignition threshold is above 1300 K. Ignition delay is a function of pressure and temperature of the gas. Ignition in similar oxygen mixtures takes place in shorter times and at lower temperatures than with N2O. Calculations on the rate of thermal decomposition ... |
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| Soft Ignition System for Self-Contained Munitions |
MAR 89 |
|
| Authors:
Michael Liva; Matthew Webb; Richard Field; ARMY ARMAMENT RESEARCH DEVELOPMENT AND ENGINEERING CENTER PICATINNY ARSENAL N J ARMAMENT ENGINEERING DIRECTORATE
|
| A laser multiple-point ignition system was designed, fabricated, and tested in a gun simulator using live propellant. Details of the fiber optic coupling to energetic materials are given including the use of a metal foil as the transfer medium. Effects of temporal characteristics of the laser are discussed. Data from the simulator test are analyzed to determine ignition delay times and overall function time for the multiple-point ignition system. ... |
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| A Parametric Study of a 40-mm Air Defense Gun Using Conventional and Traveling Charge Propellant |
MAY 1988 |
27 pages |
| Authors:
Paul G. Baer; ARMY BALLISTIC RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| Work is proceeding on a project which will use the traveling charge effect to enhance the muzzle velocity of guns used in the air defense role. In such guns increasing the muzzle velocity offers two advantages: the time of flight of the projectile is reduced, increasing the likelihood of impacting a highly mobile target; and the terminal velocity is increased, increasing the likelihood of penetration and destruction of the target. ... |
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| Radiative Augmented Combustion |
01 MAR 88 |
|
| Authors:
Moshe Lavid; M L ENERGIA INC PRINCETON NJ
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| Many combustion applications are presently limited by constraints such as flammability, flame propagation, ignition and stability imposed by the combustion process itself. Consequently much attention is being given to techniques which can augment combustion by extending these limits. One such promising technique is Radiative Augmented Combustion. It is based on the fact that radiation of selected wavelengths is capable of photodissociating stable molecule, combustion intermediates and other inhibiting species into ... |
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| Modeling of Spray Combustion in Direct Injection Diesel Engine |
30 JAN 88 |
|
| Authors:
Harmohindar Singh; David E. Klett; NORTH CAROLINA AGRICULTURAL AND TECHNICAL STATE UNIV GREENSBORO
|
| A mathematical model has been developed to predict the penetration of a transient fuel spray, the temporal and spatial distribution of air fuel mixture before the end of ignition delay and the subsequent pressure rise during combustion in a Direct Injection Diesel Engine with and without swirl. The model accounts for the non-isothermal and non-isobaric character of processes during fuel injection resulting from continuous motion of the piston. The effects ... |
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| Cetane Scale Evaluation and Possible Modification |
23 DEC 87 |
|
| Authors:
Naeim A. Henein; WAYNE STATE UNIV DETROIT MI CENTER FOR AUTOMOTIVE RESEARCH
|
| An evaluation is made of the validity and accuracy of the Cetane Scale in rating fuels used in diesel engines. Six problems have been identified, analyzed and possible solutions have been proposed. Three of the problems are intrinsic to the scale and are related to its inability to rate low ignition quality fuels, instability of the ignition delay meter and the inconformity of the CFR combustion system with actual diesel ... |
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| Effects of Ceramic Surfaces on Autoignition in a Constant Volume Combustion Apparatus |
DEC 87 |
|
| Authors:
Thomas W. Ryan III; Mike D. Kanakia; Karen B. Kohl; SOUTHWEST RESEARCH INST SAN ANTONIO TX BELVOIR FUELS AND LUBRICANTS RESEARCH FACILITY
|
| A constant volume combustion apparatus was used to determine the effects of ceramic-coated surfaces on the ignition of fuel sprays from a diesel injection nozzle. The goal was to determine if the ceramic surfaces could enhance ignition through catalytic effects on the surfaces. Statistical analysis of the data indicated that an aluminosilicate coating had no effect, while a partially stabilized zirconia increased the delay times. It appears, however, that the ... |
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| A Pyrotechnic Delay Ignition System for a Submarine Launched Marine Signal |
SEP 87 |
|
| Authors:
B. W. Whiffen; MATERIALS RESEARCH LABS ASCOT VALE (AUSTRALIA)
|
| This report describes the development of a delay ignition system for a submarine launched marine signal. The igniter, which incorporates a pyrotechnic delay element, was designed to transfer ignition from the payload expelling charge to the flare candle. The design eliminates ignition failures caused by water plumes extinguishing the igniters as the flare payload assembly is ejected from the signal canister. Keywords include: Submarine, Pyrotechnic igniters, Ignition systems, Ignition delay, ... |
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| The Development of New Procedures for Rating the Ignition Quality of Fuels for Diesel Engines |
DEC 86 |
|
| Authors:
T. W. Ryan III; SOUTHWEST RESEARCH INST SAN ANTONIO TX BELVOIR FUELS AND LUBRICANTS RESEARCH FACILITY
|
| The ignition delay times of 42 different fuels were measured in a constant voulume combustion bomb. The measurements were performed at three different initial air temperatures using fuels ranging from the primary reference fuels for cetane rating to complex mixtures of coal-derived liquids. A single-cylinder, variable compression-ratio, direct-injection diesel engine was designed and constructed to study the ignition quality of 17 of the 42 fuels. The total ignition delay times ... |
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| Ignition of Fuel Sprays |
JUN 86 |
|
| Authors:
W. A. Sirignano; H. T. Sommer; S. K. Aggarwal; CARNEGIE-MELLON UNIV PITTSBURGH PA DEPT OF MECHANICAL ENGINEERING
|
| One-dimensional unsteady calculations to study the spray ignition process were performed first for a monodisperse fuel-air spray in front of a planar heated wall and later for polydisperse single-component fuel sprays. The effect of different droplet heating models was investigated and it is found that at certain equivalence ratios ignition delay time and energies can be smaller in the heterogeneous case than in the limiting gaseous premixed case. Because of ... |
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| Aging and Surveillance Program MINUTEMAN II/III Stage II Program Progress |
MAY 86 |
231 pages |
| Authors:
AEROJET STRATEGIC PROPULSION CO SACRAMENTO CA
|
| This semiannual report provides results of tests conducted in support of the aging and surveillance program for the Minuteman II and III Stage II motors. The primary objectives of the program are to provide assurance that (1) the reliability of the presently deployed motor will not degrade within a projected replacement time of 17 years; and (2) the service life of the remanufactured motor will be equal to or greater ... |
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| Crack Propagation and Branching in Burning Solid Propellants and Ignition of Nitramine-Based Composite Propellants |
JAN 1986 |
116 pages |
| Authors:
Kenneth K. Kuo; John A. Moreci; Jong U. Kim; Takaaki Torikai; Mark Grubelich; PENNSYLVANIA STATE UNIV UNIVERSITY PARK DEPT OF MECHANICAL ENGINEERING
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| Three major tasks performed during the report period of investigation were: i) crack propagation and branching in burning solid propellants, ii) ignition of nitramine-based composite propellants under rapid pressurization, and iii) ignition of nitramine-based composite propellants by CO2 laser. Propellant samples have been recovered by interrupted burning experiments. Four modes of crack propagation and/or branching were observed. The amount of surface area generated by mixed or branched modes is substantially ... |
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| Aging and Surveillance Program MINUTEMAN II/III Stage II Program Progress |
NOV 85 |
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| Authors:
AEROJET STRATEGIC PROPULSION CO SACRAMENTO CA
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| This semiannual report provides results of tests conducted between 15 March 1985 and 31 August 1985 in support of the Aging and Surveillance program for the Minuteman II and III Stage II motors. The primary objectives of the program are to provide assurance that (1) the reliability of the presently deployed motor will not degrade within a projected replacement time of 17 years, and (2) the service life of the ... |
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| Performance Combustion Characteristics and Exhaust Emission of a Direct Injection Diesel Engine Using Water/Oil Emulsions as Fuel |
30 SEP 85 |
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| Authors:
E. M. Afify; NORTH CAROLINA STATE UNIV AT RALEIGH
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| A CLR single cylinder diesel engine is used to determine the effect of air content in the emulsified fuel on the performance, exhaust emissions and ignition delay of diesel engines. The experiments were conducted using diesel fuel no. 2 and JP-4 as baseline fuels and emulsions containing 15%, 30% and 45% water by volume. The air charge temperature was varied from 88 F to 302 F. The effects associated with ... |
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| Soft Ignition System Self-Contained Munitions |
NOV 84 |
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| Authors:
GEO-CENTERS INC NEWTON CENTRE MA
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| The principles of the proposed soft ignition system have been defined and studied and are based on a laser/fiber optic sub-system to achieve simultaneous multiple point ignition at several axial and radial positions within the propelling charge. Effective designs for laser sensitive primers were developed and demonstrated. Ignition delay and the resultant jitter were measured as a function of such variables as igniter mass and case material, etc. The resultant ... |
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Reports by Keyword(s)
IGNITION LAG
