Numerical Simulation of Liquid Rocket Exhaust Plume Radiation

[Abstract] Based on detailed analyzing of flow field, accurate simulation of radiation of the liquid rocket engine exhaust plume plays an important role for detecting, identifying, tracking in missiles defense systems. The fully coupled Navier-Stokes equations with additional terms describing one step chemical kinetics of CH4 and O2 in chamber have been used for incorporate numerical simulation of flow fields in engine and plume at 5km, 8km,20km, 30km, 40km 50km and 80km. Considering two steps reaction in chamber, plume flow field at 5km is also studied particularly. According to the effect of atmosphere attenuation and transmissivity on radiation, a generated model has been developed to calculate optical radiation parameters of the plumes at 5km. Some key features in expanding of the plume into the ambient environment have been gained, such as the location of the barrel shock impingement, the shock reflection structure, thickness of the shear layer and afterburning processes, as well as flow field temperature, pressure, velocity and mass fraction of products. The simulation results show that the shape and characteristic of exhaust plume are determined by combustion model in chamber and ambient environment. The plume produces powerful radiation over the infrared spectral ranges, and conditions of atmosphere and transmission distance have a great influence on the distribution of spectrum.