بررسی دقت مدل‏های زیرشبکه در مدل‏سازی آتش چرخان درونی توسط روش شبیه ‏سازی گردابه‏ های بزرگ

نوع مقاله: مقاله پژوهشی

نویسندگان

1 دانشگاه تربیت مدرس، دانشکده مهندسی مکانیک، گروه تبدیل انرژی

2 دانشگاه تربیت مدرس

چکیده

در این مقاله، آتش چرخشی با سوخت متانول در یک اتاق با ارتفاع زیاد، که یک شکاف در یک گوشه‏ آن ایجاد شده است، مورد بررسی قرار می‌گیرد. مدل‌سازی با استفاده از روش شبیه‏ سازی گردابه‏ های بزرگ، مدل زیرشبکه‏ اسماگورینسکی، ویل و تک­ معادله‏ای و مدل احتراقی اضمحلال گردابه انجام شده و نتایج در دو شرایط مختلف (بستر سوخت با قطر 5/8 و 7 سانتی‌متر) با نتایج تجربی مقایسه می‌شود. با مقایسه‏ نتایج عددی با نتایج تجربی مشاهده می‌شود که نتایج عددی دمای متوسط در وسط و گوشه‏ اتاق با نتایج تجربی همخوانی دارد. نتایج مدل ‏های مختلف زیرشبکه در خط مرکزی نشان می‌دهد که مدل وِیل با نتایج تجربی همخوانی بهتری دارد. همچنین عملکرد دو مدل زیرشبکه‏ تک­معادله‏ای و اسماگورینسکی بدتر از مدل ویل بوده است، به‌طوری ‌که به‌طور متوسط درصد خطای نسبی مدل وِیل ۳/۷ درصد است، درحالی ‌که هر یک از مدل‏ های اسماگورینسکی و تک ­معادله‌ای به ­ترتیب 8 و 8/9 درصد خطا نسبت­به نتایج تجربی دارند. در فواصل دور از مرکز نتایج سه مدل زیرشبکه تفاوت چندانی ندارد و همخوانی بیشتری با نتایج تجربی دیده می‌شود، به‌گونه‌ای که در گوشه‏ اتاق خطای نسبی کمتر از ۸ درصد است.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Accuracy of Sub-grid Models in Internal Fire Whirl Modeling by Large Eddy Simulation

نویسندگان [English]

  • Mohammad Safarzadeh 1
  • Ghassem Heidarinejad 2
  • Hadi Pasdarshahri 2
1 Department of Energy Conversion, Faculty of Mechanical Engineering, Tarbiat Modares University
2 Tarbiat Modares University
چکیده [English]

In this paper, a fire whirl in a high-rise room with a gap in one corner is investigated. Methanol fuel is intended. Large Eddy Simulation method was used and the OpenFoam software, one-equation sub-grid model and eddy dissipation combustion model were performed. Results in two different conditions (fuel bed of 5.8 and 7 cm) were obtained and compared with the experimental results. By comparing the numerical results with the experimental results, it is observed that the numerical results of the mean temperature in the middle and corner of the room are consistent with the experimental results. The results of the various sub-grid models in the center line show that the WALE model fits better with the experimental results and also the performance of the two one-equation and Smagorinsky sub-grid models is lower than WALE. On average, the relative error percentage of the WALE model is 7.3 percent, while each of the Smagorinsky and one-equation models have error of 8 and 8.9 percent compared to the experimental results, respectively. The results of the three sub-grid models in the corner are not significantly different and are more consistent with the experimental results. The corner line error of the room being less than 8%.

کلیدواژه‌ها [English]

  • Fire whirl
  • Large Eddy Simulation
  • WALE
  • Smagorinsky
  • One equation subgrid scales
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