Published 1995 by Center for Combustion Research, University of Colorado at Boulder, National Aeronautics and Space Administration, National Technical Information Service, distributor in Boulder, CO, [Washington, D.C, Springfield, Va .
Written in EnglishRead online
|Statement||M.C. Branch, J.W. Daily, and A. Abbud-Madrid.|
|Series||NASA contractor report -- NASA CR-200007., CCR report -- no. 95-05.|
|Contributions||Daily, James W., Abbud-Madrid, Angel., United States. National Aeronautics and Space Administration.|
|The Physical Object|
Download Ignition and combustion of bulk metals at normal, elevated, and reduced gravity
Ignition and combustion of bulk metals under elevated, normal and reduced gravity conditions This research effort is aimed at providing further insight into this multi-variable dependent phenomena by looking at the effects of gravity on the ignition and combustion behavior of metals.
Since spacecraft are subjected to higher-than-1g gravity loads during launch and reentry and to zero-gravity. Ignition and Combustion Characteristics of Pure Bulk Metals: Normal-Gravity Test Results An experimental apparatus has been designed for the study of bulk metal ignition under elevated, normal and reduced gravity by: 6.
An experimental apparatus has been designed for the study of bulk metal ignition under elevated, normal and reduced gravity environments.
The present work describes the technical characteristics of Ignition and combustion of bulk metals at normal system, the analytical techniques employed, the results obtained from the ignition of a variety of metals subjected to normal gravity conditions Cited by: 6.
Get this from a library. Ignition and combustion characteristics of pure bulk metals: normal-gravity test results: 32nd Aerospace Sciences Meeting & Exhibit, January/Reno, NV.
[Angel Abbud-Madrid; United States. National Aeronautics and Space Administration.;]. An investigation of the effect of gravity on ignition and combustion of metals has been conducted with bulk titanium and magnesium samples.
A W xenon lamp irradiates the top surface of cylindrical specimens, 4 mm in diameter and 4 mm high, in a quiescent, pure-oxygen environment at 1 atm. Reduced gravity is obtained from an aircraft flying parabolic by: TABLEOFCONTENTS Page Abstract ^ 1.
Introduction ^ 2. DescriptionofApparatus 4 TheCombustionCharaber 5 ValvingandGasControls ^ TheExperimentalSite 8 2. Piloted ignition Solid ignition Hypobaric Reduced pressure Material ﬂammability Elevated oxygen abstract There are a number of situations when ﬁres may occur at low pressures and oxygen concentrations that are different than standard atmospheric conditions, such as in buildings at high elevation, airplanes, and spacecraft.
Ignition and combustion of bulk metals at normal, elevated and reduced gravity. Article. Jan ; ignition, and combustion of bulk metals is important for fire safety in the production. Combustion of Metals in Reduced-Gravity and Extraterrestrial Environment An experimental apparatus has been designed for the study of bulk metal ignition under elevated, normal and reduced.
Comparison of Combustion Products of Bulk Aluminum Rods Burning in High Pressure Oxygen in Normal and Reduced Gravity. Simulation of Cylindrical Rod Combustion in High-Pressure Oxygen by Steady-State Jet Model.
Evaluation of Containment Boxes as a Fire Mitigation Method in Elevated Oxygen Conditions. This article will discuss the combustion of metal nanoparticles and explain the burn time dependence on particle size.
In contrary to common belief in the power law (t b ~ d ), which, in our knowledge, and reduced gravity book simply an experimental fit to data, we propose the logarithmic law (t b ~ln(d)) that describes well the known results on nano-aluminum.
The ignition-burn conditions of several ferrous metals, including AISI, AISIductile iron and, PH, and CA15 stainless steels have been determined.
The oxygen conditions involved velocities of approximately meters per second ( feet per second) and pressures of 20 to 68 atm ( to psig). When steel specimens were fractured in 68 atm ( psig), mps. The objective of this research is to investigate the effects of gravity on the ignition and the combustion characteristics of the Polyethylene (PE) film by outer heating.
Combustion experiments of PE film were carried out in a normal gravity field and the microgravity field. In the microgravity experiments, it was carried out in 50 m-class drop facility. temperatures. In order to determine these characteristics, the ignition timing, combustion temperature, and combustion intensity of the aluminum particles would be recorded during each test.
In particular, the effects of the following on the combustion of aluminum particles were deemed to. Smouldering Combustion of Solid Bulk Materials at Different Volume Fractions of Oxygen in the And reduced gravity book Gas MARCUS MALOW1 and ULRICH KRAUSE2 1Division II.2 “Reactive substances and systems” 2Division VII.3 “Fire Engineering” Federal Institute for Materials Research and Testing (BAM).
The experiment conditions of ignition and combustion for powdered fuel flow are showed as following: The testing temperature in furnace is ℃. The effective length of quartz tube heater is mm for natural ventilation.
The gravity drop-powdered fuel is about. This means that the ignition timing can be retarded a little bit and still achieve MBT. This retarding of ignition timing will decrease the combustion gas pressures before TDC, which will reduce the force required to move the piston on up to TDC.
This reduced drag effect on the pistons will increase the pumping efficiency of the engine. -reduced furnace temp. which = reduced heat transfer-reduced combustion efficiency due to reduced time in combustion zone-extra O₂ and N₂ leaving stack carry away heat reducing efficiency-pulsating flame-extra power required for forced draft fans-temps further down the flue gas path may be elevated due to increased velocity.
Ignition and burning in a still oxygen atmosphere As a preliminary step, we studied metal combustion in the absence of oxygen ﬂow under normal pressure. The sequence of images in Fig. 2 shows evolution of the top surface of a mild steel rod ex-posed to a 1kW laser radiation. On the time interval t.
10ms, the surface undergoes a slow. The bulk ignition temperatures of barium, bismuth, calcium, iron, lead, magnesium, molybdenum, strontium, tin, and zinc were found and compared to the previous results of Grosse and Conway.
The differences in the results are attributed to how the heating cycle is carried out and how the cycle affects the surface oxide coat. An illustration of an open book.
Books. An illustration of two cells of a film strip. Ignition and combustion of metals in oxygen Item Preview metals such as carbon steel exhibited a decrease in their bulk ignition temperatures, whereas metals such as Monel showed bulk ignition temperatures independent of pressure.
Addeddate The heat in metal cutting and welding processes produces very small metal and metal oxide particles classified as fumes rather than dusts.
These fumes (1 micron or less in size) create challenging combustion properties, so testing dusts or fumes to determine their combustion.
These are commonly used terms, but technically speaking these are different. Ignition refers to the process / phenomena of initiating the overall burning (burning used loosely here) process.
2 and 3. Combustion and burning are similar in the. Metal particle combustion has been widely studied over the past 50 years, and has been reviewed by Glassman5, Williams6,7, among others, and more recently by Yetter and Dryer8. The combustion mechanisms for different metals can, in general, be divided into two categories, i) the metal is relatively non-volatile and the combustion consists of.
Coal in bulk should be carefully stored to avoid spontaneous combustion. On ships regular testing of the temperatures of the hold should be done.
Carbon-dioxide stored in bulk should be used when fire is imminent and the hatches should be cooled from the outside with water sprays and not opened up until firefighting tugs or port is reached. Ignition and combustion of powdered aluminum in high-temperature gaseous media and in a composition of heterogeneous condensed systems Combustion, Explosion, and Shock Waves, Vol.
8, No. 2 Combustion of a stationary particle of low-boiling metal. Smouldering combustion is included in this chapter as it is the combustion process that is initiated by spontaneous ignition within bulk solids. Various aspects of smouldering are considered, including the chemical and physical requirements necessary for a material to be able to undergo this mode of combustion and the factors that affect the.
the products of combustion varies considerably. We will be studying the following: 1.) Nature of hydrocarbons and fuel gases 2.) Occurrence of fuel gases in nature 3.) Types of fuel gases 4.) The combustion process and the basic chemistry of combustion 5.) Gas burners and gas burner operation 6.) Venting the products of combustion.
Furthermore, a sensitivity analysis is presented, which details the role of the porosity of the Si particle bed in reducing the minimum radiant fluence for ignition. Five common metal oxides (CuO, Bi2O3, MoO3, Co3O4, and Fe2O3) are then surveyed as candidate oxidizers for improving the combustion characteristics of Boron particles, and it is.
In addition, oxygen combustion tube tests performed by our University of Calgary group indicate that low pH conditions will exist over longer durations than are observed for normal air.
While combustion tube tests have not shown higher peak temperatures with oxygen combustion, localized hot spots are observed by discoloration of the metal. Perfect Combustion (only in a lab) to occur 1 cft of natural gas + 10 cft of air = 11 cft of heat ( BTU's of heat or BTU's per cft of natural gas) Complete (typical) Combustion occurs when.
parameters such as ignition/combustion mode, ignition temperature, ignition delay time, combustion temperatures, burnout times and envelope flame soot volume fractions. Regarding ignition, in the quiescent gas condition, bituminous and subbituminous coal - particles experienced homogeneous ignition in both O.
2 /N. and O. 2 /CO. The normal phase of a material is that which exists at standard conditions of temperature [21°C (70°F)] and pressure [ psi ( kPa) or 1 atmosphere at sea level]. Combustion of a solid or liquid fuel takes place above the fuel surface in a region of vapors created by heating the fuel surface.
This book is opinionated. I have not hesitated to give my own opin ion of a program, or of the intelligence —or lack of it —of the pro posals made by various individuals. I make no apology for this, and can assure the reader that such criticism was not made with the ad vantage of hindsight.
At one point, in writing this book, when. Combustion - Combustion - Explosions: The transition from combustion to explosion is caused by an acceleration of the reaction, induced either by a rise in temperature or by increasing lengths of the reaction chain.
The first is called thermal explosion, and the second is called chain explosion. Thermal explosion theory is based on the idea that progressive heating raises the rate at which. Depleted uranium (DU; also referred to in the past as Q-metal, depletalloy or D) is uranium with a lower content of the fissile isotope U than natural uranium.
Natural uranium contains about % U, while the DU used by the U.S. Department of Defense contains % U or less. The less radioactive and non-fissile uranium constitutes the main component of depleted uranium. lated,15) IMEP, ignition timing and combustion duration are obtained.
Test Procedures The air inlet temperature is 18ºC and the humidity is 31% during experiments. Before test, the engine was warmed up until the temperatures of coolant and oil reached 80±1°C in order to eliminate their effect on combustion and emission cha-racteristics.
Combustion, or burning, is a high-temperature exothermic redox chemical reaction between a fuel (the reductant) and an oxidant, usually atmospheric oxygen, that produces oxidized, often gaseous products, in a mixture termed as tion does not always result in fire, but when it does, a flame is a characteristic indicator of the reaction.
While the activation energy must be overcome to. Combustion, a chemical reaction between substances, usually including oxygen and usually accompanied by the generation of heat and light in the form of flame. Combustion is one of the most important of chemical reactions and may be considered a culminating step in the oxidation of certain kinds of substances.
During combustion, sodium generates about the same amount of heat as an equivalent weight of wood. The principal fire hazard associated with sodium is the rapid reaction with water. It floats on water (specific gravity ), reacting vigorously and melting.
Reduced-gravity environments can be used to learn more about flame ignition, propagation, and extinction in reactivity gradients. It is now speculated that gaseous flammability limits might not exist at all, or that a diffusive or hydrodynamic mechanism may cause extinction, or that flame balls or flame strings are themselves the limiting.Internal Combustion Engine is a complex machine that does mechanical work when the air-fuel mixture is ignited under high pressure.
The Air-Fuel mixture is sent into the Combustion chamber through the intake manifold which is responsible to maintain proper supply of ignition charge into the engine always.combustion), or at a negligible rate (i.e.
more slowly than monitored, as in slow oxidation). For instance, a piece of paper enclosed in a transparent container with more air than the theoretical one, may not burn completely if ignited (e.g.
by a concentrated light), because, as oxygen concentration gets reduced.