Experimental Investigation of Self-Pressurizing Propellant Injection Into a Rocket Motor Combustion Chamber
Date
2020-12-22
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Abstract
This work details the study of nitrous oxide (N2O) two-phase-flashing flows using carbon dioxide (CO2) as an analog. An experiment was designed and performed to replicate the flashing flow through a sharp-edged rocket injector. Pressure, temperature and mass flow rate were measured across the injector channel. Data was collected for 33 critical and sub-critical flow cases across a range of upstream pressures between 4 MPa and 6 MPa. The experimental data was used to determine the prediction accuracy and robustness of the previously developed Homogeneous Relaxation Model (HRM), Homogeneous Equilibrium Model (HEM), and Delayed Equilibrium Model (DEM). Steady flow of each model through the experiment geometry was numerically represented in 1D using Runge-Kutta fourth-order methods. HRM was determined to be the best model for predicting flashing water flows, but it required adjustment of its vapourization rate to properly represent CO2 flashing flows. A genetic algorithm was used to fit HRM to the experimentally measured mass flow rate and pressure distribution. The predictions of the developed model had an average pressure error of 4.1%, and the average mass flow rate error of 2.3% across all critical flow rate experiments. This model allows rocket designers to predict N2O injection with much greater accuracy than previously.
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Keywords
Flashing, Two-phase flow, Thermal non-equilibrium
Citation
Stannard, D. (2020). Experimental Investigation of Self-Pressurizing Propellant Injection Into a Rocket Motor Combustion Chamber (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.