Numerical simulations of a axial-injection end-burning hybrid rocket motor were conducted. The combustion mechanism of this kind of hybrid rocket motor was studied. The simulation models of combustion and flow were established in consideration of both gas-solid interfacial coupling and solid fuel pyrolysis. Numerical simulations of motor combustion were carried out. Analysis shows that

two combustion models

end-burning and side-burning

exist in the motor

and the combustion models mainly depend on the oxidizer velocity. The combustion models change when the oxidizer velocity exceeds the transition velocity. Numerical simulation results also validate the existence of the two combustion models under different oxidizer velocities

and the range of transition velocity matches well with the experimental results in reference.