Abstract
In order to enlarge the system of CAMUI hybrid rocket, it is essential to estimate its performance with a minimum of combustion experiments to reduce research and development costs. The authors had built up "Prediction Model for Startup Characteristic", which simulate the pressure history of each part of the system, and "Fuel Regression History Model", which predict the weight and shape history of fuel under combustion. In this study, the authors combined the two models mentioned above, and built up the program that predict the pressure history of each part of the system, and the weight and shape history of the fuel directly from the initial parameters. The result obtained by the program agreed well with the experimental value and got adequacy. With the program, the authors designed the CAMUI fuel grain which realize the optimal fuel flow rate on 90kgf thrust class motor, of which fuel has not been optimized yet.