نویسندگان
1 دانشکده مهندسی مکانیک، دانشگاه آزاد دورود، لرستان
2 دانشکده مهندسی مکانیک، دانشگاه ملایر، ملایر
چکیده
در این مقاله، تاثیر نانوسیال آب-اکسیدآهن (Fe3O4) بر انتقال حرارت یک کانال در حضور میدان مغناطیسی متغیر عمود بر جریان، با ایجاد موانع بهصورت محوری با استفاده از مدل تکفازی مخلوط مطالعه میشود. اثرات میدان مغناطیسی با نوشتن کدهایی به معادلات حاکم بر فروسیال اضافه شده و هندسه مسئله در نرمافزار Gambit 2.4 تولید و شبکهبندی میشود. شبکه حاصل بهصورت سهبعدی تشکیل شده و معادلات دیفرانسیل غیرخطی حاکم بر مسئله نیز براساس روش حجم محدود با کمک نرمافزار فلوئنت تحلیل میشود. همچنین اثر پارامترهایی نظیر اثر موانع در مسیر جریان، عدد بیبعد شدت میدان مغناطیسی و عدد بیبعد رینولدز بر انتقال حرارت مطالعه شده است. نتایج نشان میدهد، ایجاد موانع در مسیر جریان باعث اغتشاش در جریان سیال شده، که این اغتشاش باعث افزایش انتقال حرارت کلی میشود. همچنین اعمال میدان مغناطیسی بر نانوسیال مغناطیسی سبب نفوذ لایه مرزی خنک در قسمتهای مرکزی کانال شده و با افزایش شدت میدان مغناطیسی نفوذ این لایه نیز افزایش مییابد. در نتیجه مقدار عدد ناسلت و انتقال حرارت افزایش یافته که این بهبود انتقال حرارت و عدد ناسلت با افزایش عدد رینولدز بیشتر میشود.
کلیدواژهها
عنوان مقاله [English]
Numerical Study of the Effect of Nanofluid on Heat Transfer of a Channel in the Presence of Variable Magnetic Field with Obstacles
نویسندگان [English]
- P. Gilavand 1
- H. R. Heidari 2
1
2
چکیده [English]
In this paper, the effect of water- iron oxide (Fe3O4) nanofluid on a channel heat transfer in the presence of perpendicular to the flow variable magnetic field with creating axial obstacles using a mixed single-phasee model is investigated numerically. The effects of magnetic field are added to governing equations of ferrofluid by writing codes and the problem geometry is generated and networked in Gambit 2.4 software. The network used is constructed in a three-dimensional and the governing non-linear differential equations are solved according to the finite volume method by using the Fluent software. Also, the effect of parameters such as obstacles in the flow path, dimensionless number of magnetic field intensity and Reynolds dimensionless number on heat transfer have been studied. The results show that creating obstacles in the flow path causes turbulence in the fluid flow, which increases the overall heat transfer. Also, the application of a magnetic field on the magnetic nanofluid causes the penetration of the cool boundary layer in the central parts of the channel and with increasing the intensity of the magnetic field, the penetration of this layer increases. As a result, the amount of Nusselt number and heat transfer has increased, and this improvement in heat transfer and Nusselt number increases with increasing Reynolds number.
کلیدواژهها [English]
- Nanofluid
- Channel
- Nusselt number
- Obstacles
- magnetic field
2. Pak, B. C. and Cho, Y. I., “Hydrodynamic and Heat Transfer Study of Dispersed Fluids with Submicron Metallic Oxide Particles”, Experimental Heat Transfer an International Journal, Vol. 11, No. 2, pp. 151-170, 1998.
3. Das, S. K., Putra, N., Thiesen, P. and Roetzel, W., “Temperature Dependence of Thermal Conductivity Enhancement for Nanofluids”, Journal of Heat Transfer, Vol. 125, No. 4, pp. 567-574, 2003.
4. Goldstein, L. and Sparrow, E. M., “Heat/Mass Transfer Characteristics for Flow in a Corrugated Wall Channel”, Journal of Heat Transfer, Vol. 99, No. 2, pp. 187-195, 1977.
5. Wang, C. C. and Chen, C. K., “Forced Convection in a Wavy-Wall Channel”, International Communications in Heat and Mass Transfer, Vol. 45, No. 12, pp. 2587-2595, 2002.
6. Heidary, H. and Kermani, M. J., “Effect of Nano-Particles on Forced Convection in Sinusoidal-Wall Channel”, International Communications in Heat and Mass Transfer, Vol. 37, No. 1, pp. 1520-1527, 2010.
7. Liang, G., Krishna, K., Wenquan, T. and Yogendra, J., “Parametric Numerical Study of Flow and Heat Transfer in Microchannels with Wavy Walls”, Journal of Heat Transfer, Vol. 133, No. 5, pp. 1-10, 2011.
8. Wang., Z. H. and Meng., X., “Liquid Metal Buoyancy Driven Convection Heat Transfer in a Rectangular Enclosure in the Presence of a Transverse Magnetic Field”, International International Journal of Heat and Mass Transfer, Vol. 113, No. 1, pp. 514-523, 2017.
9. Naphon, P., Wiriyasarta., S. and Arisariyawonga., T., “Magnetic Field Effect on the Nanofluids Convective Heat Transfer and Pressure Drop in The Spirally Coiled Tubes”, International Journal of Heat and Mass Transfer, Vol. 110, No. 1, pp. 739-745, 2017.
10. Odenbach, S., “Ferrofluids—Magnetically Controlled Suspensions”, Colloids and Surfaces A: Physicochemical and Engineering Aspects, Vol. 217, No. 1-3, pp. 171-178, 2003.
11. Xuan, Y., Li, Q. and Ye, M., “Investigations of Convective Heat Transfer in Ferrofluid Microflows Using Lattice-Boltzmann Approach”, International Journal of Thermal Sciences, Vol. 46, No. 2, pp. 105-111, 2007.
12. Servati, A. A., Javaherdeh, K., and Ashorynejad, H. R., “Magnetic Field Effects on Force Convection Flow of a Nanofluid in a Channel Partially Filled with Porous Media Using Lattice Boltzmann Method”, Advanced Powder Technology, Vol. 25, No. 2, pp. 666-675, 2014.
13. Freidoonimehr, N. and Rahimi, A. B., “Investigation of MHD Nano-Fluid Flow over Stretching Surface with Velocity Slip and Convective Surface Boundary Conditions”, Modares Mechanical Engineering, Vol. 15, No. 3, pp. 208-218, 2015 (in Persian).
14. Akbarzadeh, P. and Panahdoost, H., “MHD Flow of a Nanofluid Inside a Peristaltic Curved Porous Channel with Internal Heat Source”, Modares Mechanical Engineering, Vol. 17, No. 10, pp. 165-175, 2018. (in Persian)
15. Rosensweig, R. E., Ferrohydrodynamics, Courier Dover Publications, Dover Books on Physics, Cambridge University Press, 1997.
16. Kittel, C. and McEuen, P., Introduction to solid state physics, Wiley and Sons Eds., 8th Edition, New York, 1976.
17. Valiallah Mousavi, S., Sheikholeslami, M. and Barzegar Gerdroodbary, M., “The Influence of Magnetic Field on Heat Transfer of Magnetic Nanofluid in a Sinusoidal Double Pipe Heat Exchanger”, Chemical Engineering Research and Design, Vol. 113, No. 1, pp. 112-124, 2016.
18. Pak, B. C., and Cho, Y. I., “Hydrodynamic and Heat Transfer Study of Dispersed Fluid with Submicron Metallic Oxide Partical”, Experimental Heat Transfer, Vol. 11, No. 2, pp. 151-170, 1998.
19. Hamilton, R. L. and Crosser, O. K., “Thermal Conductivity of Heterogeneous Two-Component System”, Industrial and Engineering Chemistry Fundamentals, Vol. 1, No. 3, pp. 187-191, 1962.
)