A recently developed reconstruction technique is used to investigate graphite nozzle erosion in two scales of hybrid rocket motors, 30-N-thrust class and 2000-N-thrust class, using oxygen as the oxidizer and high-density polyethylene as the fuel. Thermocouple measurements taken from within the nozzles are used to estimate nozzle throat wall temperature. Forty-four static firing tests were conducted under varying experimental conditions to confirm the validity of the reconstruction technique results, to investigate the conditions at the onset of erosion, and to formulate an empirical predictive model of nozzle erosion rate. Results show that a single formula that treats the combustion gas as a single oxidizing agent for which heterogenous rate constants are functions of equivalence ratio can satisfactorily replicate the erosion rate of graphite by a combustion gas containing multiple oxidizing species. Furthermore, the chemical-kinetic-limited conditions of the onset of nozzle erosion are specified by a novel empirical correlation, which shows that erosion begins at lower temperature and pressure in oxidizer-rich combustion gas than in fuel-rich combustion gas.
Investigation of Graphite Nozzle Erosion in Hybrid Rockets Using Oxygen/High-Density Polyethylene
Journal of Propulsion and Power ; 36 , 3 ; 423-434
2020-03-27
12 pages
Aufsatz (Zeitschrift)
Elektronische Ressource
Englisch
Investigation of Graphite Nozzle Erosion in Hybrid Rockets Using O2/C2H4 (AIAA 2018-4531)
British Library Conference Proceedings | 2018
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