Modelling of soot oxidation and prediction of optical radiation in underexpanded plumes

The main goal of this work is to perfect a method to characterize and predict optical radiation from plumes due to soot particulate matter. This model can be used to study soot optical radiation at different altitudes and correlate it with engine parameters. This work is in continuation of the initial work of Brentner et al., 2003. A single-nozzle axisymmetric plume representative of the Atlas rocket is taken as the example system for different altitudes. A soot overlay method is applied on the plume flowfield solution, and the corresponding soot distribution is then used to predict intensity of light by scattering and absorption of light by the soot particulate matter by integrating the radiative transfer, equations along lines of sights from the plume to the observer. The prediction of soot combustion at different altitudes is found to be sensitive to the moddeling of turbulence in the flow. Finally, the intensity of light at different wavelengths for a particular axial station of the plume close to the nozzle is discussed.