Aluminum Flame Temperature Measurements in Solid Propellant Combustion

Abstract

The temperature in an aluminized propellant is determined as a function of height and plume depth from diatomic AlO and thermal emission spectra. Higher in the plume, 305 and 508 mm from the burning surface, measured AlO emission spectra show an average temperature with 1σ errors of 2980 ± 80 K. Lower in the plume, 152 mm from the burning surface, an average AlO emission temperature of 2450 ± 100 K is inferred. The thermal emission analysis yields higher temperatures when using constant emissivity. Particle size effects along the plume are investigated using wavelength-dependent emissivity models.

Experiments on wildfire ignition by exploding targets

“…Temperature at explosion of ANAL mixtures is about 6700 °F (4000 K) (Maranda 1990). Aluminum burning in air achieves temperatures of about 3860 to 4940 °F (2400 to 3000 K), but higher temperatures occur with greater oxygen (Beckstead 2004;Huang et al 2009;Parigger et al 2014). These reaction temperatures for the mixture and combustion of AL are obviously sufficient to ignite wildfires, being much greater than the nominal flaming ignition temperature of about 620 °F (600 K) for cellulosic wildland fuels.…”

Upgrading of crude oil in supercritical water: A five-lumped kinetic model

“…It does not only release high pressure gas to fracture the rock layers of oil reservoirs but also substantial thermal energy to transform the aqueous phase into supercritical state in down-hole zone during the combustion process [1].…”

Two-photon laser-induced fluorescence in sodium-doped composite propellant flame

“…This propellant contains 3.5% NaNO3 dopant, and there are spectral features associated with CaCl, K, Li, AlO, and Na and gray body emission. In addition, in other types of composite propellant emission spectra have also shown OH in the ultra-violet region 33 , and H2O, CO2 and CO in the infrared region 32 . More studies using emission spectroscopy have been useful in characterizing species profiles 32 , temperature 15,33 , and combustion instabilities.…”

“…In addition, in other types of composite propellant emission spectra have also shown OH in the ultra-violet region 33 , and H2O, CO2 and CO in the infrared region 32 . More studies using emission spectroscopy have been useful in characterizing species profiles 32 , temperature 15,33 , and combustion instabilities. In this thesis, emission spectroscopy is used as a global characterization of the propellant flame.…”

“…By assuming the emission spectrum follows blackbody/gray body behavior, a temperature estimate can be made by using a Planck distribution and a known wavelength-dependent calibration for the collection system. For gas phase temperature measurements, the spectra of aluminum monoxide emission has also been used to indicate the temperature 33 . These temperature measurements have been used with good success, but can present bias as the gray body emission is biased towards the condensed phase and the AlO emission represents the temperature in the diffusion flame structure of aluminum droplet combustion.…”