抄録
Regression formulas for solid fuels in CAMUI type hybrid rockets were developed. A fuel grain in this rocket consists of multiple stages of cylindrical fuel blocks with two ports. A Fuel block in a CAMUI type grain has three burning surface, i.e., the upstream end face, port inner walls, and the downstream end face. A series of static firing tests by laboratory model motor and 2500 N thrust class flight model motor gave empirical constants in the regression formulas. There regression formulas are used to obtain an optimal design of a grain configuration. However, the empirical constants provided by these two series of firing tests did not agree with each other. To investigate the cause of this disagreement, additional static firing tests by 2500 N thrust class flight model motor was conducted. Results show that the empirical constants depend on Re number. In contrast, the dependence was not observed in the firing tests by the laboratory model motor. This difference may be caused by the difference in L/D (the ratio of the length of the port and the diameter of port).
