ISSN Online: 2377-424X
ISBN Print: 0-89116-559-2
International Heat Transfer Conference 8
Radiative Properties of Aluminized Propellant Flames
要約
The spectral intensity emitted by various aluminized solid propellant flames has been measured. The pressure during combustion has been varied from atmospheric to 7.2 MPa. From the intensity measurements effective blackbody temperatures for emission as high as 4000K have been obtained which are significantly in excess of the overall adiabatic flame temperatures (1400 to 3000K). These extremely high intensities can be attributed to the combusting Al/Al2O3 droplets present in the gas phase flame region. This evidence indicates that radiant heat feedback to the burning solid propellant may be much larger than previously estimated. This finding could have significant impact on solid propellant burn rate modelling, acoustic combustion stability modelling and aluminum agglomeration modelling as now being practiced in the solid propellant industry. A model of the radiant transport in the oxide particle-laden flame was also developed for comparing theoretical with measured spectral intensities to estimate the magnitude of the radiative parameters of the flame. From this the optical depth of the flame appears to be of the order 0.1 to 1.0 and the maximum temperature in the flame zone appears to be the Al2O3 boiling temperature as has been previously suggested (4000 to 5000K depending on pressure).