Firing tests of a hybrid rocket motor were performed and analyzed in terms of pressure oscillations under various configurations, using liquid oxidizer injection or gaseous injection through a catalyzer. Most of the firing tests presented pressure oscillations in the range of 200–2000 Hz, provoked by periodic vortex shedding occurring in the postcombustion chamber. These instabilities revealed particular behaviors such as frequency shifts and jumps. To understand these phenomena, the classical theory of vortex shedding in a cavity has been adapted to hybrid rocket engines by introducing an additional parameter that aims to consider the recirculation area in the postcombustion chamber to correctly explain the frequencies’ behavior. Dedicated numerical simulations based on unsteady Reynolds-averaged Navier–Stokes equations and single-phase flow were performed to characterize this new parameter. Predictions of the proposed modeling were finally compared with the available firing tests database and revealed promising results, whatever the type of oxidizer injection, the operating combustion chamber pressure, and even in the presence of nozzle throat erosion.
Hydrodynamic Instabilities Modeling in Hybrid Rocket Engines
Journal of Spacecraft and Rockets ; 56 , 5 ; 1371-1382
2019-09-01
Article (Journal)
Electronic Resource
English
Modeling of Hybrid Rocket Low Frequency Instabilities
Online Contents | 2005
|Modeling of Hybrid Rocket Low Frequency Instabilities
AIAA | 2005
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