Analyzer for Exhaust Plume Spacecraft Surfaces

For the analysis of nozzle exhaust plume impingement effects on spacecraft surfaces, an analyzer program package was developed.

In the geometry section based on the LOHARP-VUFACT routine, the complex spacecraft surfaces are nodalized. The relative location and orientation of the surface elements with respect to the nozzle exit and plume axis are determined. In the plume flow field section the flow parameters are determined at the surface element locations based on a point source flow model including nozzle boundary layer effects. In the impingement section, the forces, torques and energy fluxes due to flow impingement are determined and summarized.

The analyzer is used to determine the impingement effects of the exhaust plumes of the north/south station keeping hydrazine thrusters on ESA-OTS 2 spacecraft surfaces. The induced pitch torques are determined among others and are compared with values deduced from flight data assessment.