شبیه‌سازی و تحلیل عددی سه بعدی تولید آنتروپی محلی و اگزرژی تخریبی در پره استاتور یک توربین‌گاز نمونه

نوع مقاله : مقاله پژوهشی

نویسندگان

گروه آموزشی آیرودینامیک، مجتمع دانشگاهی هوافضا، دانشگاه صنعتی مالک اشتر، تهران، ایران

چکیده

آنتروپی به عنوان یک پارامتر کلیدی، محدودیت تئوری عملکرد و کیفیت بسیاری از کاربردهای مهندسی را فراهم آورده است. در این پژوهش تحلیل سه بعدی تولید آنتروپی، تولید آنتروپی محلی و اگزرژی تخریبی پره استاتور توربین به کمک کدنویسی توابع فلوئنت صورت گرفته است. نوآوری کار حاضر محاسبه‌ی نرخ اگزرژی تخریبی پره سه بعدی توربین به کمک نرم‌افزار فلوئنت است. برای پیش‌بینی مناسب چسبندگی مؤثر و هدایت حرارتی مؤثر از مدل ) k-ω(SST و اسپالارت آلماراس استفاده شده است. به علت حساسیت به انحنای نوک پره و جریانات ویک، مدل k-ω(SST( متوسط تولید آنتروپی را حدود 85 درصد بیشتر از مدل اسپالارت آلماراس به دست آورد هاست. آنتروپی تولیدی محلی با توجه به مقیاس صورت گرفته از ریشه تا نوک پره افزایش یافته است. اختلاف مقادیر تولید آنتروپی محلی با قانون دوم ترمودینامیک برای مدل‌های ) k-ω(SST و اسپالارت آلماراس به ترتیب 7/ 4 و 2/ 10 درصد است. ضرایب توربولانس تقریبی به کمک تابع کاربری ساده در نرم‌افزار فلوئنت کدنویسی شده که باعث افزایش تولید آنتروپی محلی حدود 130 درصد شده است. مدل ) k-ω(SST مقدار اگزرژی تخریبی یک طبقه توربین را )طبق قضیه گویا-استودلا( 1098 کیلو وات محاسبه کرده که به علت مقیاس در نظر گرفته شده 4 برابر حالت دوبعدی است. مقادیر تولید آنتروپی محلی محاسبه شده در مقایسه با پره‌ی استاتور توربین مقاله معتبر اعتبارسنجی شده است که تطابق قابل قبولی دارد.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

3D-Simulation and Numerical Analysis of the Local Entropy Generation and Exergy Destruction in a Stator Vane of a Typical Gas Turbine

نویسندگان [English]

  • Mohsen Soroushan
  • Hamid Parhizkar
  • Jamasb Pirkandi
Aerospace Department, Malek Ashrar University of Technology, Tehran, Iran
چکیده [English]

Entropy serves as a key parameter in achieving the theoretical limits of performance and quality in many engineering applications. In this paper, the three-dimensional analysis of entropy generation, local entropy generation and exergy destruction of turbine stator vane by user defined function code have been done. The current innovation is to calculate the exergy destruction rate of the turbine three-dimensional vane with the help of FLUENT software. The k-ω (SST) and Spalart-Allmaras models are suitable for prediction of proper effective viscous and thermal conductivity. Due to the sensitivity to the tip of the vane and the wake flows, k-ω (SST) model obtained the mean value of entropy generation by about 85% more than the Spalart-Allmaras model. Local entropy generation has increased with respect to the scale from the root to the tip of the vane. The difference between the values of local entropy generation and the second law of thermodynamic for k-ω (SST) and Spalart-Allmaras models are 7.4% and 10.2%, respectively. Approximate turbulence coefficients have been introduced with the aid of a custom field function that increases the local entropy generation about 130%. The k-ω (SST) model calculated the exergy destruction value of a turbine stage of 1098 kW, which is 4 times the size of the two-dimensional mode due to the scale. The values of local entropy generation calculated in comparison with the stator vane of the turbine of the authentic paper are validated, which has acceptable adaptation.

کلیدواژه‌ها [English]

  • Laboratory stator turbine vane
  • Local entropy generation
  • Second
  • law of thermodynamics
  • Exergy destruction
  • Three-dimensional numerical simulation
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