Life time evaluation of an annular-type combustion chamber based on coupled thermal-fluid-structure simulation

The combustion chamber of liquid rocket engines is under extreme thermal and structural conditions. For development of highly-reliable reusable rocket engines, it is indispensable to precisely evaluate the life time of combustion chambers. In our past studies, the coupled thermal-fluid-structure simulation method, which consists of quasi-one-dimensional hot-gas flow calculation, quasi-one-dimensional coolant flow calculation, and three-dimensional thermal-structure calculation of chamber wall by using FEM, was developed for predicting the chamber lifetime. However, the verification of the proposed method was not enough because there were few experimental data to validate computed results in terms of the chamber life time. In this paper, the proposed method was further validated against the experimental data of an annular-type combustion chamber obtained in hot firing tests, which were carried out in the Kakuda Space Center (KSC) of JAXA. Also, three-dimensional combustion simulation was implemented in the coupled simulation in order to predict the hot-gas side wall heat flux on the chamber wall without using a tuning parameter that is included in a Nu-type empirical correlation in our original method. The computed chamber wall temperature and chamber life time based on the linear cumulative damage rule were validated against the experimental data.