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<p>Present work involves numerical CFD study of the flame structure of PMMA sphere at different velocities of the incident oxidizer flow under zero-gravity conditions. The performed modeling allowed us to establish the chemical processes to change significantly with a variation of velocity of the oxidizer flow. It was shown that both the thermal and chemical structure of the flame change, as well as the temperature gradient and the mechanism of heat release in the gas phase. It has been established that with an increase in the flow velocity, the combustion completeness decreases that is explained by an increase in the flame strain rate and, consequently, a decrease in the residence time in the chemical reaction zone. Calculation of the heat release rates in individual reactions at various oxidizer flow velocities allowed us to identify four key reactions determining the overall heat release rate. At average flow velocity values, the main contribution to the heat release is made by the HO<sub>2</sub> + OH = H<sub>2</sub>O +O<sub>2</sub> step, which is explained by a high concentration of HO<sub>2</sub> in the flame. The remaining key steps in decreasing order of their contribution to the heat release are T-C<sub>3</sub>H<sub>5</sub> + O<sub>2</sub> = CH<sub>3</sub> + CO + CH<sub>2</sub>O, HCO + O<sub>2</sub> = CO + HO<sub>2</sub> and CH<sub>3</sub> + O = H + H<sub>2</sub> + CO.</p>

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Numerical Study of Crucial Effect of Forced Convection on the Structure of PMMA Flame Under Microgravity Conditions

  • 期刊论文

  • 发表日期：

    2026年5月19日

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  • Tatyana Bolshova,
  • Vladimir Shvartsberg

摘要

Present work involves numerical CFD study of the flame structure of PMMA sphere at different velocities of the incident oxidizer flow under zero-gravity conditions. The performed modeling allowed us to establish the chemical processes to change significantly with a variation of velocity of the oxidizer flow. It was shown that both the thermal and chemical structure of the flame change, as well as the temperature gradient and the mechanism of heat release in the gas phase. It has been established that with an increase in the flow velocity, the combustion completeness decreases that is explained by an increase in the flame strain rate and, consequently, a decrease in the residence time in the chemical reaction zone. Calculation of the heat release rates in individual reactions at various oxidizer flow velocities allowed us to identify four key reactions determining the overall heat release rate. At average flow velocity values, the main contribution to the heat release is made by the HO2 + OH = H2O +O2 step, which is explained by a high concentration of HO2 in the flame. The remaining key steps in decreasing order of their contribution to the heat release are T-C3H5 + O2 = CH3 + CO + CH2O, HCO + O2 = CO + HO2 and CH3 + O = H + H2 + CO.