Numerical Study of the Dynamic Characteristics of Pintle Nozzles for Variable Thrust

摘要

Unsteady numerical simulations of pintle nozzles were implemented to investigate dynamic characteristics of various pintle configurations. To take into account the effects of the pintle shape and movement, a sliding mesh method was applied. The physical nozzle throat based on pintle location was analytically investigated and found to compare well with numerical results. The static and dynamic results are verified with the experimental results. The flow separation shock trams as the pintle strokes are analyzed according to the three pintle models. The response lag and sensitivity of the chamber pressure and nozzle performance were evaluated for pintle reciprocation, insertion, and extraction processes to better understand the dynamic performance of the pintle nozzle. The pressure coupling effects of the propellant burning surface during the pintle reciprocation are conducted, which are compared with the cold-flow cases.