Mechanistic Model for Aluminum Particle Ignition and Combustion in Air

2005 ◽  
Vol 21 (3) ◽  
pp. 478-485 ◽  
Author(s):  
Paul E. DesJardin ◽  
James D. Felske ◽  
Mark D. Carrara
Keyword(s):  
Mechanistic Model ◽  
Aluminum Particle ◽  
Particle Ignition ◽  
Ignition And Combustion

scholarly journals Measurements in Solid Propellant Plumes at Ambient Conditions

2011 ◽  
Author(s):  
Jonathan L. Height ◽  
Burl A. Donaldson ◽  
Walter Gill ◽  
Christian G. Parigger
Keyword(s):  
Temperature Distribution ◽  
Solid Propellant ◽  
Aluminum Particle ◽  
Burning Surface ◽  
Ambient Conditions ◽  
Aluminum Particles ◽  
Open Atmosphere ◽  
Particle Ignition ◽  
Accident Scenarios ◽  
Color Pyrometer

The study of aluminum particle ignition in an open atmosphere propellant burn is of particular interest when considering accident scenarios for rockets carrying high-value payloads. This study investigates the temperature of an open atmosphere Atlas V solid propellant burn as a function of height from the burning surface. Two instruments were used to infer this temperature: a two-color pyrometer and a spectrometer. The spectra were fitted to a model of energy states for aluminum monoxide. The temperature which provided the best match between the model and data was taken as the reaction temperature. Emissions above 30 inches from the surface of the propellant were not sufficiently strong for data reduction, perhaps obscured by the alumina smoke cloud. The temperature distribution in the plume increased slightly with distance from the burning surface, presumably indicating the delay in ignition and heat release from the larger aluminum particles in the propellant. The pyrometer and spectrometer results were found to be in excellent agreement indicating plume temperatures in the range of 2300K to 3000K.

Aluminum Particle Ignition Studies

2012 ◽  
Author(s):  
Michael S. Cornelius ◽  
Burl Donaldson
Keyword(s):  
Atmospheric Pressure ◽  
Molten Aluminum ◽  
Pressure Pulse ◽  
Aluminum Particle ◽  
Oxide Shell ◽  
Ignition Process ◽  
Particle Sizes ◽  
Aluminum Particles ◽  
Particle Ignition ◽  
Arc Heating

Experiments have been performed to study the combustion criteria of aluminum particles at atmospheric pressure. The primary goal is to quantify the outcome for a particle into which thermal energy has been deposited. Experiments utilized instantaneous joule heating of an aluminum wire. Once the particle was generated, it fell under gravity and the flight was recorded by video; in some cases, the ignited particle quenched or fragmented, and the residue was collected for SEM and EDS imaging. This provided information related to the aluminum oxide shell which was formed when combustion occurred. These experiments produced particles of approximately 150450 microns in the arc heating tests. In a second set of experiments, particles were produced under more observable time scales. This provided observation of the oxide skin, which is known to influence the ignition process. This experiment utilized a pressure pulse to eject a small droplet of molten aluminum through a small orifice. From this experiment, particle sizes ranging 2–3 mm were produced.

Towards a Mechanistic Model for Aluminum Particle Combustion

2003 ◽  
Author(s):  
Prasanth George ◽  
Paul E. DesJardin
Keyword(s):  
Melting Temperature ◽  
Mechanistic Model ◽  
Mass Loss Rate ◽  
Current Model ◽  
Aluminum Particle ◽  
Temperature History ◽  
Heterogeneous Combustion ◽  
Linear Ordinary Differential Equations ◽  
Particle Combustion ◽  
State Diffusion

A relatively simple mechanistic model for the combustion of an aluminum particle in air is presented. The model assumes combustion to occur in two stages. In the first stage, phase transition and heterogeneous surface reactions take place until the melting temperature of the oxide is reached. In the second stage, a quasi-steady state diffusion flame is established allowing for the use of commonly employed flame sheet approximations. Modified Ranz-Marshall and standard drag correlations for a sphere are used to describe the unsteady heating, mass loss rate, and drag of the particle, with the surrounding gas. A system of non-linear ordinary differential equations are formulated and numerically integrated in time for predictions of particle mass, temperature and velocity with, and without, the effects of heterogeneous combustion. Results indicate that, within the assumptions of the current model, the effects of heterogeneous combustion have a significant impact on the overall particle burn time and temperature history for gas temperatures ranging from 1500 to 2500 K. At higher particle Reynolds number, and for temperatures greater than 2500 K, the effects of heterogeneous combustion are not as important and an ignition criterion based on the oxide melting temperature may be sufficient.

Ignition and combustion of a single aluminum particle in hot gas flow

2018 ◽  
Vol 196 ◽  
pp. 35-44 ◽  
Author(s):  
Yunchao Feng ◽  
Zhixun Xia ◽  
Liya Huang ◽  
Likun Ma
Keyword(s):  
Gas Flow ◽  
Aluminum Particle ◽  
Hot Gas ◽  
Ignition And Combustion

scholarly journals Single particle ignition and combustion of anthracite, semi-anthracite and bituminous coals in air and simulated oxy-fuel conditions

2014 ◽  
Vol 161 (4) ◽  
pp. 1096-1108 ◽  
Author(s):  
Juan Riaza ◽  
Reza Khatami ◽  
Yiannis A. Levendis ◽  
Lucía Álvarez ◽  
María V. Gil ◽  
...  
Keyword(s):  
Single Particle ◽  
Particle Ignition ◽  
Bituminous Coals ◽  
Ignition And Combustion
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