This paper describes computational fluid dynamics applied to the analysis of a hybrid rocket motor with a diaphragm in the combustion chamber to enhance rocket performance. This work follows the last author’s experiments: An engine was tested with nitrous oxide and paraffin wax as propellants. Several of the tests have been used as references for numerical simulations. The following approximations have been made: steady-state conditions, eddy dissipation model with one-step reaction, gaseous injection of fuel and oxidizer, and no droplets entrainment (typical of a paraffin grain). First of all, a single geometry without a diaphragm has been analyzed with different turbulence models (, shear stress transport, , renormalization group). It has been shown that the model predicts a lower flame temperature and chamber pressure than the model. Then, five geometries have been studied to compare two different types of diaphragms (one hole and four holes) in two positions (24 and 33% of the total length) to a configuration without any mixer. The effect of the diaphragm is to increase the mixing of the chemical species participating in the combustion process. The use of the diaphragm causes a performance enhancement, as shown in the experimental study. There is a good agreement between computational fluid dynamics results and experimental data: The efficiency is overestimated by less than 5.5%. This work proves the capability of computational fluid dynamics to predict global hybrid rocket performance: It can be considered as a useful tool in the study of mixing devices.
Investigation of Effect of Diaphragms on the Efficiency of Hybrid Rockets
Journal of Propulsion and Power ; 30 , 1 ; 175-185
2013-12-31
11 pages
Article (Journal)
Electronic Resource
English
Investigation of Effect of Diaphragms on the Efficiency of Hybrid Rockets
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