NUMERICAL ACTIVITIES ON THE PARAFFIN-BASED FUEL MTM IN THE FRAMEWORK OF THE PHAEDRA PROJECT

In this paper numerical activities performed on the 1 kN MTM (Material Test Motor), in the framework of the PHAEDRA project, will be presented and discussed. The MTM sub-scale engine was designed and tested for TPS (Thermal Protection System) materials characterization, by means of a firing test campaign. The engine adopts GOX and a specific paraffin-based fuel formulation. CFD simulations were carried out, in the preliminary phase, to support the engine design, specifically to predict the thermo-chemical environment faced by the TPS and to evaluate thermal loads necessary for thermo-mechanical analyses. Moreover, CFD analyses supported the choice of the injection system. Later, numerical tools, considering proper gas-surface interaction models, were adopted to investigate the fuel characteristic, engine operative conditions and performances. Results, presented in this paper, focused on the analysis of the nozzle throat erosion at different operating conditions, explaining the differences experimentally observed when switching from fuel rich to oxidizer rich conditions