بررسی اختلاط دو سیال متفاوت در یک میکروکانال با پره منحنی شکل به روش بولتزمن

نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانشجوی دکتری، دانشکده مکانیک، دانشگاه یزد، یزد، ایران

2 دانشگاه یزد

3 استادیار، دانشکده مهندسی، دانشگاه میبد، میبد، ایران

چکیده

در مطالعه حاضر اختلاط دو سیال با لزجت‌های متفاوت در یک میکرو کانال مجهز به پره نوسانی منحنی شکل به روش شبکه بولتزمن با زمان آسایش چندگانه شبیه سازی شده و اثرات شکل هندسی، سرعت و دامنه نوسان پره و نسبت لگاریتمی لزجت بر بازده اختلاط بررسی شده است. در مطالعات صورت گرفته در زمینه اختلاط، پره در میکرو کانال به شکل استوانه و یا مستطیل و در اکثر مطالعات دو سیال یکسان در نظر گرفته شده است. در این تحقیق برای اولین بار از پره منحنی شکل جهت اختلاط دو سیال با لزجت متفاوت استفاده شده است. شبیه سازی در عدد رینولدز 80 ، عدد اشمیت 10 انجام شده و برای پره منحنی از شکل ایرفویل ( NASA/LANGLEY LS(1) −0417 (GA(W) −1 استفاده شده است. نتایج نشان داد که بازده اختلاط دو سیال با لزجت یکسان و متفاوت، در میکرو کانال مجهز به پره منحنی شکل بالاتر از میکرو کانال مجهز به پره مستطیل شکل است. همچنین نتایج نشان داد که در دامنه‌های نوسان بررسی شده با افزایش عدد استروهال، بازده نیز افزای ش می‌یابد، بازده اختلاط در دامنه نوسان 5/ 0 در تمام اعداد استروهال بررسی شده یک مقدار بهینه را دارد و با افزایش نسبت لگاریتمی لزجت در اعداد استروهال بررسی شده، بازده کاهش می‌یابد.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Numerical Simulation of Mixing Two Fluids of Different Viscosities in a Microchannel with Curved Stirrer by Lattice Boltzmann Method

نویسندگان [English]

  • Reza Kaveh 1
  • Mohammad Sefid 2
  • Mohsen Mozafari shamsi 3
1 Ph.D. Student, Departmet of Mechanical Engineering, University of Yazd, Yazd, Iran
2 mechanical engineering yazd university yazd
3 Assistant Professor, Departmet of Engineering, University of Meybod, Meybod, Iran
چکیده [English]

In the present study, mixing of two fluids of different viscosities in a micro channel with an oscillating curved stirrer was simulated by multi relaxation time Lattice Boltzmann method and the effect of geometric shape, oscillating speed and amplitude and viscosity logarithmic ratio on mixing efficiency was analyzed. In researches in this field, the stirrer is considered as cylinder or rectangle shape and in most these researches, two fluids are same. In this study, a curved stirrer was used for mixing two fluids of different viscosities in microchannel for the first time. Calculations are performed for the dimensionless parameters of the problem including the oscillation amplitude K, viscosity logarithmic ratio R and Strouhal number St for Re=80 and Sc=10. NASA/LANGLEY LS(1)-0417 (GA(W)-1) airfoil shape was used for curved stirrer. Results showed that mixing efficiency of two fluids of same and different viscosities in microchannel with oscillating curved stirrer was higher than microchannel with oscillating rectangle stirrer. In addition, results revealed that increase in Strouhal number causes increase in mixing efficiency on studied oscillating amplitude. Optimum efficiency is on oscillating amplitude 0.5 on all studied Strouhal numbers. Also mixing efficiency decreases with increase of viscosity logarithmic ratio on studied Strouhal numbers.

کلیدواژه‌ها [English]

  • Mixing
  • Micro channel
  • Different viscosities
  • Oscillating curved stirrer
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