Robust and Optimized Design for Liquid Rocket Engine

It is important for liquid rocket engine designers to keep enough margins in order to determine the optimum engine configuration in the early phase of the development. In the LE-X engine, which is under study in JAXA for the next booster engine, statistical design process is applied to visualize quantitatively the margin and the correlation of engine system / components performance, reliability, and cost, and to determine the optimum engine configuration. First, we extract the evaluation functions which affect the engine system performance, reliability and cost, and the design parameters which have a large impact on the evaluation functions. Each design parameter allocated to the orthogonal array. Using the orthogonal array, response surface of each evaluation function is caluculated including the production variation. The margins of the evaluation functions and the factor effect between the evaluation functions and the design parameters are calculated and visualized by engine system analysis. Considering the analysis error and development risks, this analysis leads to the optimization of the design parameters of the LE-X engine along with the designers requirement.