Modeling Multiphase Effects in the Combustion of HMX and RDX
| Autor: | Ephraim B. Washburn, Merrill W. Beckstead |
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| Rok vydání: | 2006 |
| Předmět: | |
| Zdroj: | Journal of Propulsion and Power. 22:938-946 |
| ISSN: | 1533-3876 0748-4658 |
| DOI: | 10.2514/1.12689 |
| Popis: | RDX and HMX have similar structures and bur ning rates. However, the burning -rate temperature sensitivity ( �p) is significantly different between RDX and HMX at low pressures. Recent efforts to mathematically model the steady -state combustion of RDX and HMX with detailed chemical kinetics in the gas phase and distributed decomposition in the condensed phase hav e succeeded in modeling burning rates at a specific initial temperature. However, all have failed to calculate thep trends of HMX at low pressure and differentiate thep of RDX and HMX. RDX and HMX both burn with a thin multi -phase surface of bubbles i n liquid. A liquid -bubble submodel was developed to improvep calculations. Calculations including the liquid -bubble submodel produced the desired trends in both the HMX and RDXp values. To predict the observed HMXp values with the model, first, evapo ration in the sub -surface was limited near the gas -liquid surface. Second, the difference in surface temperature at different initial temperatures was adjusted to follow trends in experimental data. Third, the Marangoni effect was added to the calculation of the bubble velocities. At low pressures, the Marangoni effect was found to be greater in the higher initial temperature calculations because the temperature gradient was steeper. For RDX, there was little change in the calculatedp values with the addition of the liquid - bubble submodel. This is the first combustion model with detailed gas phase kinetics to predict the properp trends for both HMX and RDX. |
| Databáze: | OpenAIRE |
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