Plumes from hydrocarbon-fueled rockets usually contain some amount of soot. Soot radiates a continuous, nearblackbodyspectrum, and, as such, even a minor amount of soot plays a critical role in the characteristics of theinfrared radiation emission. The contribution of soot to the plume radiation depends on several factors including;the amount of soot, particle physical characteristics, concentration, and temperature distribution in the flow field.The temperature and trajectories of solid particles can differ from those of the plume due to the particle’smechanical and thermal inertia. Exhaust plume simulations were performed using the CFD FLUENT code forsolving two-phase Navier-Stokes equations, coupled with chemical reactions and soot particle combustion.Exhaust plumes with soot mass loading of 2% were simulated for three altitudes of 2km, 8km and 16km. Radialdistributions of the cloud particle density were obtained for different distances along the flow. The particleconcentration increased at the plume periphery, as a result of the particle deceleration at the boundary layer insidethe nozzle. The particle temperature is higher than the gaseous temperature of the plume. The temperaturedifference between the soot particle and the plume along corresponding trajectories is about 5% – 10%. Theinfrared radiation from the plumes with carbon soot was calculated. Its intensity was found to be dependent onparticle distribution in the plume.
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