Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : September 11, 2022 - September 14, 2022
Interstellar Technologies, Inc. has been developing a series of liquid rockets using ethanol/LOX called MOMO. These rockets use graphite nozzle throat inserts for which nozzle erosion, referring to the increase in diameter of the nozzle throat due to the chemical reactions between the combustion gas and the graphite, has become a problem. This study aims to develop a predictive equation for the nozzle erosion rate of liquid rockets using ethanol/LOX. The authors analyzed data from seven long-duration combustion experiments and calculated the nozzle erosion rate. Using the heat transfer coefficient of the nozzle throat, the heat transfer equation at the nozzle throat was solved and the nozzle wall temperature was also estimated. As a result, it was found that the nozzle erosion phenomenon of liquid rockets using ethanol/LOX has a similar trend to that of nozzle erosion in hybrid rockets using HDPE/LOX. A good correlation was obtained by using the nozzle erosion rate prediction equation of Kamps et al., which has chamber pressure, equivalence ratio and nozzle wall temperature as parameters.
