Because rocket turbopump turbine blades have higher loading, there is a possibility of shaft vibration problem due to “Thomas Force”. In order to reduce shaft vibrations, it is important to keep “Thomas Force”small, In the previous report, validity of optimization process for the reduction of Thomas Force was confirmed by performing Parameter Design and Multi-Objective Genetic Algorithm(MOGA). In this paper, by increasing the number of objective functions, the results of multi-objective optimization for reduction of Thomas Force and the considering the feasibility of blade structure are discussed. It was found that optimized blade reduced 10％in weight, 30％in Thomas Force, compared from the original blade.
