Köşe Bölmeli Kare Muhafazada Nanopartikül Şekil Etkisinin Doğal Konveksiyon Üzerine Etkileri

Bu çalışmada, farklı şekillerde nanopartiküller ile doldurulmuş köşe bölmeli kare boşlukta doğal konveksiyonun sayısal incelenmesi sonlu elemanlar yöntemi kullanılarak gerçekleştirilmiştir. Boşluğun sol ve sağ dikey duvarları sabit sıcaklıkta tutulurken, yatay duvarlar adyabatik ve köşe bölmesi iletkentir. Sayısal çalışma farklı nanopartikül şekilleri ve köşe bölmesinin yarıçapı, katı nanopartikül hacim kesirleri, Rayleigh sayılarının çeşitli değerleri için uygulanmıştır. Rayleigh sayısının, nanopartikül hacim kesrinin ve iletken bölmenin boyutunun artması, ortalama ısı transferini arttırdığı gözlemlenmiştir. Silindir şeklindeki nanopartiküller en iyi performansı gösterirken, küresel olanlar da ısı transferinin iyileştirilmesi açısından en kötü performansı göstermektedir.

Anahtar Kelimeler:

Konjuge doğal konveksiyon, Nanoakışkanlar, Köşe bölme, Sonlu elemanlar yöntemi

Nanoparticle Shape Effect on Natural Convection in a Corner Partitioned Square Cavity

In this study, numerical investigation of natural convection in a corner partitioned square cavity filled with nanoparticles of different shapes was performed by using finite element method. The left and right vertical walls of the cavity are kept at constant temperatures while the horizontal walls are adiabatic and the corner partition is conductive. The numerical study was performed for various values of Rayleigh numbers, solid nanoparticle volume fractions, radii of the corner partition and different nanoparticle shapes. It was observed that average heat transfer enhances as the value of the Rayleigh number, nanoparticle volume fraction and size of the conductive partition increases. Cylindrical shape nanoparticles show the best performance and spherical ones show the worst performance in terms of heat transfer enhancement.

Keywords:

Conjugate natural convection, Nanofluids, Corner partition, Finite element method,

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1. Selimefendigil, F., Oztop, H.F., 2016. Conjugate Natural Convection in a Cavity with a Conductive Partition and Filled with Different Nanofluids on Different Sides of the Partition, Journal of Molecular Liquids, vol. 216, pp. 67-77.
2. Oztop, H.F., Varol, Y., Koca A., 2009. Natural Convection in a Vertically Divided Square Enclosure by a Solid Partition into air and Water Regions, International Journal of Heat and Mass Transfer, vol. 52, pp. 5909-5921.
3. Varol, Y., Oztop, H.F., Pop, I., 2008. Natural Convection Flow in Porous Enclosures with Heating and Cooling on Adjacent Walls and Divided by a Triangular Massive Partition, International Communications in Heat and Mass Transfer, vol. 35, pp. 476-491.
4. Ahmed, E.S., Oztop, H.F., Al-Salem, K., 2014. Natural Convection Coupled with Radiation Heat Transfer in an Inclined Porous Cavity with Corner Heater, Computers & Fluids, vol. 102, pp. 74-84.
5. Selimefendigil, F., Oztop, H.F., 2015. Natural Convection and Entropy Generation of Nanofluid Filled Cavity Having Different Shaped Obstacles under the Influence of Magnetic Field and Internal Heat Generation, Journal of the Taiwan Institute of Chemical Engineers, vol. 56, pp. 42-56.
6. Selimefendigil, F., Oztop, H.F., 2014. Pulsating Nanofluids Jet Impingement Cooling of a Heated Horizontal Surface, International Journal of Heat and Mass Transfer, vol. 69, pp. 54-65.
7. Bouhalleb, F., Abbasi, H., 2015. Natural Convection in an Inclined Rectangular Enclosure Filled by CuO–H2O Nanofluid, with Sinusoidal Temperature Distribution, International Journal of Hydrogen Energy, vol. 40, pp. 13676-13684.
8. Zakaria, I., Azmi, W.H., Mamat, A.M.I., Mamat Rizalman Saidur, R., Abu Talib, S.F., 2016. Thermal Analysis of Al2O3–Water Ethylene Glycol Mixture Nanofluid for Single PEM Fuel Cell Cooling Plate: An Experimental Study, International Journal of Hydrogen Energy, vol. 41, pp. 5096-5112.
9. Shahnazar, S., Bagheri, S., Abd Hamid, S.B., 2016. Enhancing Lubricant Properties by Nanoparticle Additives, International Journal of Hydrogen Energy, vol. 41, pp. 3153-3170.
10. Selimefendigil, F., Oztop, H.F., Abu-Hamdeh, N., 2015. Mixed Convection Due to Rotating Cylinder in an İnternally Heated and Flexible Walled Cavity Filled with SiO2–Water Nanofluids: Effect of Nanoparticle Shape, International Communications in Heat and Mass Transfer, vol. 71, pp. 9-19.
11. Selimefendigil, F., Oztop, H.F., 2015. Mixed Convection in a Two-sided Elastic Walled and SiO2 Nanofluid Filled Cavity with İnternal Heat Generation: Effects of Inner Rotating Cylinder and Nanoparticle’s Shape, Journal of Molecular Liquids, vol. 212, pp. 509-516.