TÜRBÜLATÖR İÇEREN KISMİ DALGALI BİR KANALDA TÜRBÜLANSLI ISI TRANSFER ANALİZİ

Öz

Bu çalışma, dairesel türbülatör içeren kısmi dalgalı bir kanalda türbülanslı ısı transferini sayısal olarak araştırmaktadır. Simülasyonlar, ANSYS Fluent programı kullanılarak gerçekleştirilir. Kanalın giriş ve çıkış bölümleri düz ve adyabatiktir. Kanalın ortasında dairesel türbülatör içeren kısmi dalgalı bir bölüm mevcuttur. Dalgalı yüzeyler q″ = 2000 W/m2 sabit ısı akısında tutulmaktadır. Çalışmada iş yapan akışkan havadır. Viskoz model olarak standart k-ε türbülans modeli kullanılmıştır. Reynolds sayısı 3000≤Re≤6000 aralığında değişmiştir. Farklı Reynolds sayılarında, türbülatörlü ve türbülatörsüz durum için çıkış sıcaklığı, yüzey sıcaklığı, ısı transfer katsayısı, Nusselt sayısı, basınç düşüşü, sürtünme faktörü ve termohidrolik performans hesaplanmıştır. Kanalda dairesel türbülatörün hız ve sıcaklık dağılımları üzerindeki etkisi paylaşılmıştır. Elde edilen bulgular, Re artması ile çıkış sıcaklığının, yüzey sıcaklığının ve sürtünme katsayısının düştüğünü göstermiştir. Bunun yanında, Re artması, ısı transfer katsayısını, Nusselt sayısını ve basınç düşüşünü artırmıştır. Türbülatörlü kanalda ısı transferi ve basınç düşüşü türbülatörün olmadığı kanala göre daha yüksektir. En yüksek Nusselt sayısı, Re=6000 ve türbülatörlü durumda Nu=55,81 olarak hesaplanmıştır. Re=6000’de türbülatörlü kanalda ısı transferi türbülatörsüz kanala göre %15 iyileşmiş ancak basınç düşüşü biraz artış göstermiştir. En yüksek THP, Re=5000’te türbülatörlü kanalda 1,041 olarak elde edilmiştir.

Anahtar Kelimeler

• Kısmi dalgalı kanal
• Dairesel türbülatör
• Isı transferi iyileştirme
• Sayısal çalışma

ANALYSIS OF TURBULENT HEAT TRANSFER IN A PARTIALLY WAVY CHANNEL WITH TURBULATOR

Öz

This study numerically examined turbulent heat transfer in a partially wavy channel containing a circular turbulator. The simulations are performed using the ANSYS Fluent program. The inlet and outlet surfaces of the channel are flat and adiabatic. A partially wavy section containing a circular turbulator exists in the middle of the channel. The wavy surfaces are maintained at a constant heat flux q″ = 2000 W/m². The working fluid in this study is air. The standard k-ε turbulence model was used as the viscous model. The Reynolds number varied in the range of 3000 ≤ Re ≤ 6000. For different Reynolds numbers, the outlet temperature, surface temperature, heat transfer coefficient, Nusselt number, pressure drop, friction factor and thermohydraulic performance were calculated for both the with/without turbulator cases. The effect of the circular turbulator on velocity and temperature distributions in the channel is shared. The findings show that as the Re increases, the outlet temperature, surface temperature, and friction coefficient decrease. In addition, increasing the Re increased the heat transfer coefficient, Nusselt number, and pressure drop. In the channel containing turbulator, heat transfer and pressure drop were higher than in the channel without turbulator. The highest Nusselt number was calculated as Nu = 55.81 at Re = 6000 and in the channel with turbulator. At Re = 6000, heat transfer in the channel with turbulator improved by 15% compared to the channel without turbulator, but the pressure drop increased slightly. The highest THP was obtained as 1.041 at Re=5000 in the channel with turbulator.

Anahtar Kelimeler

• Partially wavy channel
• Circular turbulator
• Heat transfer enhancement
• Numerical study

Kaynakça

1. J. Zhang, X. Zhu, M.E. Mondejar, F. Haglind, A review of heat transfer enhancement techniques in plate heat exchangers, Renew. Sustain. Energy Rev., 101 (2019) 305–328. https://doi.org/10.1016/j.rser.2018.11.017
2. E. Çelik, S. Akcay, Investigation of the effect of wave amplitude and circular obstacles on flow and heat transfer in a sinusoidal wave channel, Gümüşhane Univ. J. Sci. Techn., 15 (1) (2025) 36–50. https://doi.org/10.17714/gumusfenbil.1563367
3. S.S. Ajarostaghi, M. Zaboli, H. Javadi, B. Badenes, J.F. Urchueguia, A review of recent passive heat transfer enhancement methods, Energies, 15 (3) (2022) 986. https://doi.org/10.3390/en15030986
4. N. Kurtulmus, B. Sahin, A review of hydrodynamics and heat transfer through corrugated channels, Int. Commun. Heat Mass Transf., 108 (2019) 104307. https://doi.org/10.1016/j.icheatmasstransfer.2019.104307
5. M.A. Alfellag, H.E. Ahmed, M.G. Jehad, A.A. Farhan, The hydrothermal performance enhancement techniques of corrugated channels: A review, J. Therm. Anal. Calorim., 147 (2022) 10177–10206. https://doi.org/10.1007/s10973-022-11247-1
6. E.N. Krishnan, H. Ramin, A. Guruabalan, C.J. Simonson, Experimental investigation on thermo-hydraulic performance of triangular cross-corrugated flow passages, Int. Commun. Heat Mass Transf., 122 (2021) 105160. https://doi.org/10.1016/j.icheatmasstransfer.2021.105160
7. Z.-X. Li, S.-Q. Sung, C. Wang, C.-H. Liang, S. Zeng, T. Zhong, W.-P. Hud, C.-N. Feng, The effect of trapezoidal baffles on heat and flow characteristics of a cross-corrugated triangular duct, Case Stud. Therm. Eng., 33 (2022) 101903. https://doi.org/10.1016/j.csite.2022.101903
8. R.K. Ajeel, W.I. Salim, K. Hasnan, Design characteristics of symmetrical semicircle-corrugated channel on heat transfer enhancement with nanofluid, Int. J. Mech. Sci., 151 (2019) 236–250. https://doi.org/10.1016/j.ijmecsci.2018.11.022

9. H. Togun, R.Z. Homod, Z.M. Yaseen, A.M. Abed, J.M. Dhabab, R.K. Ibrahem, S. Dhahbi, M.M. Rashidi, G. Ahmadi, W.A. Yaïci, J.M. Mahdi, Efficient heat transfer augmentation in channels with semicircle ribs and hybrid nanofluids, Nanomaterials, 12 (15) (2022) 2720. https://doi.org/10.3390/nano12152720
10. H. Zontul, H. Hamzah, N. Kurtulmuş, B. Şahin, Investigation of convective heat transfer and flow hydrodynamics in rectangular grooved channels, Int. Commun. Heat Mass Transf., 126 (2021) 105366. https://doi.org/10.1016/j.icheatmasstransfer.2021.105366
11. R.K. Ajeel, W. Saiful-Islam, K.B. Hasnan, Thermal and hydraulic characteristics of turbulent nanofluids flow in trapezoidal-corrugated channel: Symmetry and zigzag shaped, Case Stud. Therm. Eng., 12 (2018) 620–635. https://doi.org/10.1016/j.csite.2018.08.002
12. M. Khoshvaght-Aliabadi, Influence of different design parameters and Al2O3-water nanofluid flow on heat transfer and flow characteristics of sinusoidal-corrugated channels, Energy Convers. Manag., 88 (2014) 96–105. https://doi.org/10.1016/j.enconman.2014.08.042
13. M.E. Nakhchi, Experimental optimization of geometrical parameters on heat transfer and pressure drop inside sinusoidal wavy channels, Therm. Sci. Eng. Prog., 9 (2019) 121–131. https://doi.org/10.1016/j.tsep.2018.11.006
14. M. Khan, I.N. Alsaduni, M. Alluhaidan, W.-F. Xia, M. Ibrahim, Evaluating the energy efficiency of a parabolic trough solar collector filled with a hybrid nanofluid by utilizing double fluid system and a novel corrugated absorber tube, J. Taiwan Inst. Chem. Eng., 124 (2021) 150–161. https://doi.org/10.1016/j.jtice.2021.04.045
15. D. Uysal, S. Akçay, Numerical study of thermal and hydrodynamic characteristics of turbulent flow in hybrid corrugated channels with different wave profiles, J. Mech. Eng. Sci. 18 (2) (2024) 10026–10045.https://doi.org/10.15282/jmes.18.2.2024.5.0792
16. L. Zhang, D. Che, Influence of corrugation profile on the thermal-hydraulic performance of cross-corrugated plates, Numer. Heat Transf. A, 59 (4) (2011) 267–296. https://doi.org/10.1080/10407782.2011.540963
17. M. Ahmed, M. Yusoff, K. Ng, N. Shuaib, Effect of corrugation profile on the thermal–hydraulic performance of corrugated channels using CuO–water nanofluid, Case Stud. Therm. Eng., 4 (2014) 65–75. https://doi.org/10.1016/j.csite.2014.07.001
18. M. Salami, M. Khoshvaght-Aliabadi, A. Feizabadi, Investigation of corrugated channel performance with different wave shapes, J. Therm. Anal. Calorim., 138 (5) (2019) 3159–3174. https://doi.org/10.1007/s10973-019-08361-y
19. A. Shahsavar, S.S. Alimohammadi, I.B. Askari, H.M. Ali, Numerical investigation of the effect of corrugation profile on the hydrothermal characteristics and entropy generation behavior of laminar forced convection, Int. Commun. Heat Mass Transf., 121 (2021) 105117. https://doi.org/10.1016/j.icheatmasstransfer.2021.105117
20. L.K. Nitturi, V.K.S. Kapu, R. Gugulothu, A. Kaleru, V. Vuyyuri, A. Farid, Augmentation of heat transfer through passive techniques, Heat Transfer 52 (6) (2023) 4422–4449.https://doi.org/10.1002/htj.22877
21. B.K. Kanchan, G.K. Chandan, J. Kumar, Effect of obstacle configuration in sinusoidal BFSC on hydrothermal performance and irreversibility characteristics: A numerical study, Iran J. Sci. Technol. Trans. Mech. Eng., 48 (2024) 145–162. https://doi.org/10.1007/s40997-023-00649-7
22. A. Raza, J. Hasnain, S.S. Shah, R.U. Haq, A. Alhushaybari, Influence of solid cylinders on fluid flow and thermal analysis in a curved channel with constant magnetic field, Int. Commun. Heat Mass Transf., 158 (2024) 107887. https://doi.org/10.1016/j.icheatmasstransfer.2024.107887
23. Y. Zheng, H. Yang, H. Mazaheri, A. Aghaei, N. Mokhtari, M. Afrand, An investigation on the influence of the shape of the vortex generator on fluid flow and turbulent heat transfer, J. Therm. Anal. Calorim., 143 (2021) 1425–1438. https://doi.org/10.1007/s10973-020-09415-2
24. A. Naderifar, M. Nikian, K. Javaherdeh, M. Borji, Numerical investigation of the effect of fins on heat transfer enhancement of a laminar non-Newtonian nanofluid flow through a corrugated channel, J. Therm. Anal. Calorim., 147 (2022) 9779–9791. https://doi.org/10.1007/s10973-022-11222-w
25. S. Akcay, Numerical study of turbulent heat transfer process in different wavy channels with solid and perforated baffles, Heat Transf. Res., 54 (18) (2023) 53–82. https://doi.org/10.1615/HeatTransRes.2023046621
26. S. Akçay, N.A.H. Ismael, M.A.S. Sadeq, Thermohydraulic performance analysis in an asymmetric trapezoidal wavy channel with circular turbulators, Sinop Üniv. J. Natural Sci., 10 (1) (2025) 149–164. https://doi.org/10.33484/sinopfbd.1631618
27. F.P. Incropera, D.P. DeWitt, Fundamentals of heat and mass transfer, Literatur Publishing, Istanbul, 2000.