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Türbülans Şiddetinin Dairesel Bir Silindir Üzerinde Oluşan Akış Yapısına ve Aerodinamiğine Etkisi

Yıl 2021, Cilt: 36 Sayı: 4, 901 - 912, 29.12.2021
https://doi.org/10.21605/cukurovaumfd.1040480

Öz

Bu araştırmada, kritik altı Reynolds sayısının, Re=5×103 olduğu durumda k-ω tabanlı DES türbülans modeli kullanılarak türbülans şiddetinin dairesel bir silindir etrafındaki zamana bağlı akış yapısı üzerindeki etkisi hakkında sayısal bir çalışma yapılmıştır. Sayısal analizlere göre, türbülans şiddeti arttıkça ayrılmış akış bölgesinin uzunluğu azalmaktadır. Silindirin arka bölgesinde oluşan ayrılmış akış bölgesinin uzunluğu, Ls silindirin çapı, D ile boyutsuzlaştırılmış ve bu değer, Ls/D türbülans şiddetinin Tu=%0,8 olduğu durumda Ls/D =1,225 olarak ölçülürken, türbülans şiddetinin Tu=%7 olduğu durumda Ls/D =1,0822 değerine azalmıştır. Ayrıca silindir yüzeyinde mutlak negatif basınç katsayısının maksimum olduğu nokta, türbülans şiddeti arttıkça silindir arka bölgesinde oluşan durma noktasına yaklaşmıştır. Türbülans şiddetinin, Tu=%0,8 olduğunu durumdan Tu=%7 ve %12 olduğu durumlara arttırıldığında, sürükleme katsayısının, CD arttığı gözlemlenmiştir. Buradan türbülans şiddeti seviyesinin dairesel bir silindir etrafında oluşan akış karakteristiği ve aerodinamiği üzerinde etkili olduğu sonucuna varılmıştır.

Kaynakça

  • 1. Pinar, E., Ozkan, G. M., Durhasan, T., Aksoy, M.M., Akilli, H., Sahin, B., 2015. Flow Structure Around Perforated Cylinders in Shallow Water. Journal of Fluids and Structures, 55, 52-63.
  • 2. Ozgoren, M., Pinar, E., Sahin, B., Akilli, H., 2011. Comparison of Flow Structures in the Downstream Region of a Cylinder and Sphere. International Journal of Heat and Fluid Flow, 32(6), 1138-1146.
  • 3. Rashidi, S., Hayatdavoodi, M., Esfahani, J.A., 2016. Vortex Shedding Suppression and Wake Control: A Review. Ocean Engineering, 126, 57-80.
  • 4. Najafi, L., Firat, E., Akilli, H., 2016. Time-averaged Near-wake of a Yawed Cylinder. Ocean Engineering, 113, 335-349
  • 5. Mannini, C., 2015. Applicability of URANS and DES Simulations of Flow Past Rectangular Cylinders and Bridge Sections. Computation, 3(3), 479-508.
  • 6. You, J.Y., Kwon, O.J., 2010. Numerical Comparisons Between URANS and Hybrid RANS/LES at a High Reynolds Number Flow Using Unstructured Meshes. International Journal of Aeronautical and Space Sciences, 11(1), 41-48.
  • 7. Uzun, A., Yousuff Hussaini, M., 2012. An Application of Delayed Detached Eddy Simulation to Tandem Cylinder Flow Field Prediction. Computers and Fluids, 60, 71-85.
  • 8. Travin, A., Shur, M., Strelets, M., Spalart P., 1999. Detached-Eddy Simulations Past a Circular Cylinder. Flow, Turbulence and Combustion, 63, 293-313.
  • 9. Zhao, W., Wan, D., Sun R., 2016. Detached-Eddy Simulation of Flows Over a Circular Cylinder at High Reynolds Number. Twenty-Sixth International Ocean and Polar Engineering Conference.
  • 10. Zhao, R., Yan, C., 2012. Detailed Investigation of DETACHED-EDDY Simulation for the Flow Past a Circular Cylinder at Re=3900. Applied Mechanics and Materials, 232, 471-476.
  • 11. Karasu, I., 2019. Silindir Etrafındaki Kararsız Akışın Farklı Türbülans Modelleri ile Sayısal Olarak İncelenmesi. Bilecik Şeyh Edebali Üniversitesi, Fen Bilimleri Dergisi, 6(1), 77-84.
  • 12. Norberg, C., Sunden, B., 1987. Turbulence and Reynolds Number Effects on the Flow and Fluid Forces on a Single Cylinder in Cross Flow. Journal of Fluids and Structures, 1(3), 337-357.
  • 13. Bloor, M.S., 1964. The Transition to Turbulence in the Wake of a Circular Cylinder. Journal of Fluid Mechanics, 19(02), 290.
  • 14. Gerrard, J.H., 1965. A Disturbance-sensitive Reynolds Number Range of the Flow Past a Circular Cylinder. Journal of Fluid Mechanics, 22(01), 187.
  • 15. Ahn, J., Sparrow, E., Gorman, J., 2017. Turbulence Intensity Effects on Heat Transfer and Fluid-flow for a Circular Cylinder in Crossflow. International Journal of Heat and Mass Transfer, 113, 613-621.
  • 16. Smith, M.C., 1966. Effects of Turbulence on Laminar Skin Friction and Heat Transfer. Physics of Fluids, 9(12), 2337.
  • 17. Sundén, B., 1979. A Theoretical Investigation of the Effect of Freestream Turbulence on Skin Friction and Heat Transfer for a Bluff Body. International Journal of Heat and Mass Transfer, 22(7), 1125-1135.
  • 18. Sidebottom, W., Ooi, A., Jones, D., 2015. A Parametric Study of Turbulent Flow Past a Circular Cylinder Using Large Eddy Simulation. Journal of Fluids Engineering, 137(9), 091202.
  • 19. Durhasan, T., Pinar, E., Ozkan, G. M., Akilli, H., Sahin, B., 2019. The Effect of Shroud on Vortex Shedding Mechanism of Cylinder. Applied Ocean Research, 84, 51–61.
  • 20. Menter, F.R., Kuntz, M., Langtry, R., 2003. Ten Years of Industrial Experience with the SST Turbulence Model. Turbulence, Heat and Mass Transfer, 4(1), 625–632.
  • 21. Norberg, C., 1987. Effects of Reynolds Number and a Low-intensity Freestream Turbulence on the Flow Around a Circular Cylinder, Chalmers University, Goteborg, Sweden, Technological Publications, 1–55.
  • 22. Moussaed, C., Wornom, S., Salvetti, M.V., Koobus, B., Dervieux, A., 2014. Impact of Dynamic Subgrid-scale Modeling in Variational Multiscale Large-eddy Simulation of Bluff-body Flows. Acta Mechanica, 225(12), 3309–3323.
  • 23. Pang, A.L., Skote, M., Lim, S.Y., 2016. Modelling High Re Flow Around a 2d Cylindrical Bluff Body Using the k-ω (sst) Turbulence Model. Progress in Computational Fluid Dynamics, An International Journal, 16(1), 48.
  • 24. Wang, H.F., Zhou, Y., Mi, J., 2012. Effects of Aspect Ratio on the Drag of a Wall-mounted Finite-length Cylinder in Subcritical and Critical Regimes. Experiments in Fluids.

The Turbulence Intensity Effect on the Flow Characteristics and Aerodynamics of a Circular Cylinder

Yıl 2021, Cilt: 36 Sayı: 4, 901 - 912, 29.12.2021
https://doi.org/10.21605/cukurovaumfd.1040480

Öz

In this investigation, a numerical study about the turbulence intensity effect on the time-dependent flow structure around a circular cylinder employing k-ω based Detached Eddy Simulation (DES) turbulence model was performed at sub-critical Reynolds number of Re=5×103. According to the numerical analyses, the length of recirculation region reduces as the level of turbulence intensity augments. While the normalized length of recirculation region after the cylinder, Ls/D is measured as 1.225 at turbulence intensity of Tu=0.8%, it reduces to the value of Ls/D =1.0822 at turbulence intensity of Tu=7%. Furthermore, the location of peak negative pressure coefficient moves in downstream direction by increasing turbulence intensity. The drag coefficient, CD was observed to increase when turbulence intensity increases from Tu=0.8% to 7% and 12%. Thus, it was concluded that the level of turbulence intensity is effective on changing the flow characteristics and aerodynamics of a circular cylinder.

Kaynakça

  • 1. Pinar, E., Ozkan, G. M., Durhasan, T., Aksoy, M.M., Akilli, H., Sahin, B., 2015. Flow Structure Around Perforated Cylinders in Shallow Water. Journal of Fluids and Structures, 55, 52-63.
  • 2. Ozgoren, M., Pinar, E., Sahin, B., Akilli, H., 2011. Comparison of Flow Structures in the Downstream Region of a Cylinder and Sphere. International Journal of Heat and Fluid Flow, 32(6), 1138-1146.
  • 3. Rashidi, S., Hayatdavoodi, M., Esfahani, J.A., 2016. Vortex Shedding Suppression and Wake Control: A Review. Ocean Engineering, 126, 57-80.
  • 4. Najafi, L., Firat, E., Akilli, H., 2016. Time-averaged Near-wake of a Yawed Cylinder. Ocean Engineering, 113, 335-349
  • 5. Mannini, C., 2015. Applicability of URANS and DES Simulations of Flow Past Rectangular Cylinders and Bridge Sections. Computation, 3(3), 479-508.
  • 6. You, J.Y., Kwon, O.J., 2010. Numerical Comparisons Between URANS and Hybrid RANS/LES at a High Reynolds Number Flow Using Unstructured Meshes. International Journal of Aeronautical and Space Sciences, 11(1), 41-48.
  • 7. Uzun, A., Yousuff Hussaini, M., 2012. An Application of Delayed Detached Eddy Simulation to Tandem Cylinder Flow Field Prediction. Computers and Fluids, 60, 71-85.
  • 8. Travin, A., Shur, M., Strelets, M., Spalart P., 1999. Detached-Eddy Simulations Past a Circular Cylinder. Flow, Turbulence and Combustion, 63, 293-313.
  • 9. Zhao, W., Wan, D., Sun R., 2016. Detached-Eddy Simulation of Flows Over a Circular Cylinder at High Reynolds Number. Twenty-Sixth International Ocean and Polar Engineering Conference.
  • 10. Zhao, R., Yan, C., 2012. Detailed Investigation of DETACHED-EDDY Simulation for the Flow Past a Circular Cylinder at Re=3900. Applied Mechanics and Materials, 232, 471-476.
  • 11. Karasu, I., 2019. Silindir Etrafındaki Kararsız Akışın Farklı Türbülans Modelleri ile Sayısal Olarak İncelenmesi. Bilecik Şeyh Edebali Üniversitesi, Fen Bilimleri Dergisi, 6(1), 77-84.
  • 12. Norberg, C., Sunden, B., 1987. Turbulence and Reynolds Number Effects on the Flow and Fluid Forces on a Single Cylinder in Cross Flow. Journal of Fluids and Structures, 1(3), 337-357.
  • 13. Bloor, M.S., 1964. The Transition to Turbulence in the Wake of a Circular Cylinder. Journal of Fluid Mechanics, 19(02), 290.
  • 14. Gerrard, J.H., 1965. A Disturbance-sensitive Reynolds Number Range of the Flow Past a Circular Cylinder. Journal of Fluid Mechanics, 22(01), 187.
  • 15. Ahn, J., Sparrow, E., Gorman, J., 2017. Turbulence Intensity Effects on Heat Transfer and Fluid-flow for a Circular Cylinder in Crossflow. International Journal of Heat and Mass Transfer, 113, 613-621.
  • 16. Smith, M.C., 1966. Effects of Turbulence on Laminar Skin Friction and Heat Transfer. Physics of Fluids, 9(12), 2337.
  • 17. Sundén, B., 1979. A Theoretical Investigation of the Effect of Freestream Turbulence on Skin Friction and Heat Transfer for a Bluff Body. International Journal of Heat and Mass Transfer, 22(7), 1125-1135.
  • 18. Sidebottom, W., Ooi, A., Jones, D., 2015. A Parametric Study of Turbulent Flow Past a Circular Cylinder Using Large Eddy Simulation. Journal of Fluids Engineering, 137(9), 091202.
  • 19. Durhasan, T., Pinar, E., Ozkan, G. M., Akilli, H., Sahin, B., 2019. The Effect of Shroud on Vortex Shedding Mechanism of Cylinder. Applied Ocean Research, 84, 51–61.
  • 20. Menter, F.R., Kuntz, M., Langtry, R., 2003. Ten Years of Industrial Experience with the SST Turbulence Model. Turbulence, Heat and Mass Transfer, 4(1), 625–632.
  • 21. Norberg, C., 1987. Effects of Reynolds Number and a Low-intensity Freestream Turbulence on the Flow Around a Circular Cylinder, Chalmers University, Goteborg, Sweden, Technological Publications, 1–55.
  • 22. Moussaed, C., Wornom, S., Salvetti, M.V., Koobus, B., Dervieux, A., 2014. Impact of Dynamic Subgrid-scale Modeling in Variational Multiscale Large-eddy Simulation of Bluff-body Flows. Acta Mechanica, 225(12), 3309–3323.
  • 23. Pang, A.L., Skote, M., Lim, S.Y., 2016. Modelling High Re Flow Around a 2d Cylindrical Bluff Body Using the k-ω (sst) Turbulence Model. Progress in Computational Fluid Dynamics, An International Journal, 16(1), 48.
  • 24. Wang, H.F., Zhou, Y., Mi, J., 2012. Effects of Aspect Ratio on the Drag of a Wall-mounted Finite-length Cylinder in Subcritical and Critical Regimes. Experiments in Fluids.
Toplam 24 adet kaynakça vardır.

Ayrıntılar

Birincil Dil İngilizce
Konular Mühendislik
Bölüm Makaleler
Yazarlar

İlyas Karasu Bu kişi benim

Sergen Tümse Bu kişi benim 0000-0003-4764-747X

Yayımlanma Tarihi 29 Aralık 2021
Yayımlandığı Sayı Yıl 2021 Cilt: 36 Sayı: 4

Kaynak Göster

APA Karasu, İ., & Tümse, S. (2021). The Turbulence Intensity Effect on the Flow Characteristics and Aerodynamics of a Circular Cylinder. Çukurova Üniversitesi Mühendislik Fakültesi Dergisi, 36(4), 901-912. https://doi.org/10.21605/cukurovaumfd.1040480