Prediction of Unsteady Loads and Analysis of Flow Changes due to Turbine Blade Manufacturing Variations during the Development of Turbines for the MB-XX Advanced Upper Stage Engine

Boeing-Rocketdyne in collaboration with Mitsubishi Heavy Industries is developing a new upper stage cryogenic engine, denominated MB60. The engine is destined for the Delta IV vehicle and is rated at 60000 lbf thrust level. This paper will provide a description of the design of the two turbines, which power the LH2 and LOX pumps. Special attention has been given to the design of the LH2 turbopump, and in particular to the turbine, which has been designed to operate at high speed, with maximized blade loading. Advanced 3-D CFD flow analysis based on unsteady, multi-stage viscous flow algorithms has been used in conjunction with advanced stress analysis in order to mitigate risks associated with unsteady blade forces and high-cycle fatigue. Fabrication constraints and variations will be discussed. Rapid 2-D CFD flow analysis has been used to evaluate the performance consequences of such manufacturing variations, which may alter the blade design profiles.