Combustion characteristics of hybrid rocket motor with segmented grain

In this paper, to improve the combustion efficiency and the regression rate in hybrid rocket motor, we introduce a concept that two different grain configurations are deployed into one combustion chamber, which is called the segmented grain in following chapters. Both numerical and experimental investigations are conducted. In the simulation part, the combustion efficiency and the distributions of regression rate, temperature and mass fraction of species in segmented grain cases are obtained. The corresponding firing tests are performed by the lab-scale motor with 90% H₂O₂ and PE propellant combination. The combustion efficiency and average regression rates are achieved in each test case. The numerical and experimental results agree well, and demonstrate that the segmented grain configuration proves its ability of enhancing the combustions efficiency and the regression rate of the hybrid rocket motor. Comparing with the contrast cases, the combustion efficiency of segmented grain cases are raised by 15% and around 10% in the simulations and tests, respectively. The regression rates of the after-section grain are also increased according to simulation and test results.