열구조적 신뢰도 향상을 위한 터보펌프 터빈 개발 현황

For the improvement of thermo-mechanical reliability of a gas-generator cycle liquid rocket engine turbine, rotor configuration modification and post-EDM manufacturing process were studied and developed. For the rotor configuration modification, effects of shroud thickness, groove insertion on disk near the blade hub, and shroud splitting were numerically investigated focused on the stress concentration. Eventually, an optimum configuration was devised that minimizes the accumulated plastic strain on the turbine blade fillets. Post-EDM manufacturing was aimed at the perfect removal of recast layer on the turbine blades and relevant pre-chemical treatment and post machining methods were tested. Finally selected process accomplished recast layer free blade surfaces. Measured surface roughness was lower than 0.4Ra.