بررسی اثرات فشار و دما در شعله متقابل آرام گذر-بحرانی و فرا-بحرانی متان و اکسیژن مایع

نوع مقاله: مقاله پژوهشی

نویسندگان

1 دانشگاه صنعتی شریف

2 دانشکده هوافضا، دانشگاه صنعتی شریف

چکیده

در مقاله حاضر یک شعله برخورد متقابل آرام متان-اکسیژن در شرایط ترمودینامیکی فرا-بحرانی و گذر-بحرانی مورد بررسی قرار گرفته است. از کد منبع باز Cantera جهت محاسبه میدان جریان و حل سینتیک احتراق استفاده شده است و شرایط معادله حالت، معادله انرژی و خواص انتقال جهت حل جریان گاز واقعی در شرایط ترمودینامیکی گذر-بحرانی و فرا-بحرانی اصلاح شده است. مشخصات ترمودینامیکی مانند ظرفیت حرارت ویژه با اضافه شدن ترم تکمیلی به ترم شرایط ایده آل بازنویسی شده است و معادله حالت نیز برای شرایط گاز واقعی به صورت کیوبیک آورده شده است. با حل میدان جریان در شرایط گذر بحرانی مشاهده می شود که اعمال شرایط گاز واقعی سبب پدیدار شدن شرایط شبه جوشش در میدان جریان می شود در صورتیکه با حل گاز ایده آل این پدیده مشاهده نمی شود. در نهایت مشاهده می شود که شرایط گذر-بحرانی در مقایسه با شرایط فرا-بحرانی، شعله بسیار به اعمال رابطه گاز واقعی حساس تر می باشد. در میدان کسر مخلوط اختلاف عمده ای بین حل گاز واقعی و گاز ایده آل دیده نمی شود که این نتیجه برای حل جریان آشفته بحرانی به روش فلیملت مهم می باشد. در میدان فیزیکی اختلاف بین شرایط گاز واقعی و گاز ایده آل از لحاظ موقعیت و ابعاد شعله برای حالت گذر-بحرانی قابل توجه می باشد. برای شرایط کاملا بحرانی در میدان فیزیکی نیز اختلاف قابل توجهی در شرایط موقعیت شعله رخ نمی دهد.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Influence of Inlet Temperature and Pressure in Transcritical and Supercritical Laminar Counter-Flow Flame of Liquid Oxygen/ Gaseous Methane

نویسندگان [English]

  • حامد زینی وند 1
  • hossein Ashini 2
  • Mohammad Farshchi 1
1 Sharif university of technology
2 Aerospace Department, Sharif University of Technology
چکیده [English]

In the present paper, a laminar counter-flow flame has been numerically investigated under the transcritical and supercritical conditions. The Cantera open source code has been used to calculate the flow field and the kinetic combustion solution. Furthermore, the energy equation, the thermodynamics and the transport properties have been modified for real gas solution. The thermodynamics properties, including density, enthalpy, and specific heat at constant pressure, are evaluated based on fundamental thermodynamics theories and the modified SRK equation of state (EOS). Transport properties, including thermal conductivity and dynamic viscosity, are estimated using Chung method. It can be seen that the pseudo-boiling phenomenon has been appeared in transcritical condition with real gas equations. The ideal gas solution is unable to capture this phenomenon. In the mixture fraction field, there is no major difference between the real gas and the ideal gas, which is important for solving the turbulent reacting flow by the flamelet models. However In the physical field, the difference between the real gas condition and the ideal gas is significant in terms of the position and dimensions of the flame for the transcritical state. For supercritical conditions in the physical field similar to mixture fraction field, there is no significant difference in the flame situation.

کلیدواژه‌ها [English]

  • Counter-flow flame
  • Transcritical flame
  • pseudo-boiling phenomenon
  • Cantera code
  • One-dimensional solution
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