Flow Structures Downstream of Square-shaped Cylinder in Channel

Yıl 2021, , 607 - 614, 30.09.2021

Nazım Kurtulmuş

https://doi.org/10.21605/cukurovaumfd.1004989

Öz

Experiments were conducted to investigate the flow topology downstream of a square-shaped cylinder situated in a straight channel. The critical parameters such as the Reynolds number (Re = 500) and the blockage ratio of the square-shaped cylinder (25%) were determined in light of the literature. A Particle image velocimetry (PIV) system was used to obtain the instantaneous velocity vector map. The flow structures, including the time-mean vorticity distribution, <ω> instantaneous and time-mean streamline topology, Ψ, distributions of streamwise velocity fluctuations, urms, turbulent kinetic energy, TKE are presented with Figures.

Anahtar Kelimeler

Confined cylinder, Flow structures, PIV

Düz Kanal İçerisine Yerleştirilmiş Kare Şekilli Silindir Ardındaki Akış Yapısı

Öz

Bu çalışmada, düz kanal içerisine yerleştirilmiş kare silindir ardındaki akış yapısını araştırma amacıyla deneyler gerçekleştirilmiştir. Çalışmadaki belirleyici parametreler, Reynolds sayısı, Re ve bloklama oranı, β sırasıyla 500 ve %25 olarak literatür doğrultusunda belirlenmiştir. Çalışmada, anlık hız alanını ölçmek için, parçacık görüntülemeli hız ölçüm sistemi (PIV) sistemi kullanılmıştır. Zaman ortalama eşdeğer girdaplar,<ω>, ortalama ve anlık akım çizgileri, Ψ, akım yönündeki hız çalkantılarının karelerinin karekökü, urms, türbülans kinetik enerji, TKE dağılımını içeren akış yapıları şekillerle sunulmuştur.

Anahtar Kelimeler

Akış yapıları, Sınırlandırılmış silindir, PIV

Kaynakça

• 1. Zdravkovich, M.M., 1997. Flow around Circular Cylinders, Vol. 1: Fundamentals. Oxford University Press, New York.
• 2. Williamson, C.H.K., 1996. Vortex Dynamics in the Cylinder Wake. Ann. Rev. Fluid Mech., 28, 477–539.
• 3. Yoon, D.H., Yang, K.S., Choi, C.B., 2010. Flow Past a Square-shaped Cylinder with an Angle of Incidence. Physics of Fluids, 22, 043603.
• 4. Jiang, H., Cheng, L., 2020. Flow Separation Around a Square-shaped Cylinder at Low to Moderate Reynolds Numbers. Physics of Fluids, 32, 044103.
• 5. Zafar, F., Alam, M., 2019. Flow Structure Around and Heat Transfer from Cylinders Modified from Square to Circular. Physics of Fluids, 31, 083604.
• 6. Davis, R.W., Moore, E.F., Purtell, L.P., 1984. A Numerical-experimental Study of Confined Flow Around Rectangular-shaped Cylinders. Physics of Fluids, 27, 46- 59.
• 7. Camarri, S., Giannetti, F., 2007. On the Inversion of the von Karman Street in the Wake of a Confined Square-shaped Cylinder. Journal of Fluid Mechanics, 574, 169-178.
• 8. Rahnama, M., Hadi-Moghaddam, H., 2005. Numerical Investigation of Convective Heat Transfer in Unsteady Laminar Flow over a Square-shaped Cylinder in a Channel. Heat Transfer Engineering, 26, 21-29.
• 9. Sharma, A., Eswaran, V., 2005. Effect of Channel Confinement on the Two-dimensional Laminar Flow and Heat Transfer across a Square-shaped Cylinder. Numerical Heat Transfer, Part A, 47, 79–107.
• 10.Reyes, M., Velazquez, A., Martin, E., Arias, J.R., 2013. Experimental Study on the Confined 3D Laminar Flow Past a Square Prism with a High Blockage Ratio. International Journal of Heat and Fluid Flow, 44, 444–457.
• 11. Athinarayanan, A.S.K., Gurunathan, M., Parthasarathy, R.K., Taler, J., Oclon, P., Taler, D., 2019. Numerical Investigation of Heat Transfer from Flow Over Square-shaped Cylinder Placed in a Confined Channel Using Cu-water Nanofluid. Thermal Science, 23, 1367-1380.
• 12. Dhiman, A.K., Chhabra, R.P., Eswaran, V., 2005. Flow and Heat Transfer Across a Confined Square-shaped Cylinder in the Steady Flow Regime: Effect of Peclet Number. International Journal of Heat and Mass Transfer, 48, 4598–4614.
• 13. Dhiman, A.K., Chhabra, R.P., Eswaran, V., 2008. Steady Flow Across a Confined Square-shaped Cylinder: Effects of Power-law Index and Blockage Ratio. J. Non-Newtonian Fluid Mech., 148, 141–150
• 14. Hegedűs, F., Hős, C., Pandula, Z., Kullmann, L., 2010. Measurement on the Cavitating Vortex Shedding Behind Rectangular-shaped Obstacles. IOP Conf. Ser.: Earth Environmental Science, 12, 012066.
• 15. Shadaram, A., Fard, M.A., Rostamy, N., 2008. Experimental Study of Near Wake Flow Behind a Rectangular-shaped Cylinder American Journal of Applied Science, 5, 917-926.
• 16. Farhadi, M., Rahnama, M., 2005. Three-dimensional Study of Separated Flow Over a Square-shaped Cylinder by Large Eddy Simulation. Proc. IMechE Part G: J. Aerospace Engineering, 219, 225-234
• 17. Kim, D.H., Yang, K.S., Senda, M., 2004. Large Eddy Simulation of Turbulent Flow Past a Square-shaped Cylinder Confined in a Channel. Computers & Fluids, 33, 81–96.
• 18. Nakagawa, S., Senda, M., Kikkawa, S., Wakasugi, H., Hiraide, A., 1998. Heat Transfer in Channel Flow Around a Rectangular-shaped Cylinder. Heat Transfer-Japanese Research, 27, 84-97.
• 19. Nakagawa, S., Nitta, K., Senda, M., 1999. An Experimental Study on Unsteady Turbulent Near Wake of a Rectangular-shaped Cylinder in Channel Flow. Experiments in Fluids, 27, 284-294.
• 20. Ortega-Casanova, J., 2017. On the Onset of Vortex Shedding from 2D Confined Rectangular-shaped Cylinders Having Different Aspect Ratios: Application to Promote Mixing Fluids. Chemical Engineering & Processing: Process Intensification, 120, 81-92.
• 21.Rosales, J.L., Ortega, A., Humphrey, L.A.C., 2000. A Numerical Investigation of the Convective Heat Transfer in Unsteady Laminar Flow Past a Single and Tandem Pair of Square-shaped cylinders in a Channel. Numerical Heat Transfer, Part A, 38:443-465.
• 22. Kurtulmuş, N., Zontul, H., Sahin, B., 2020. Heat Transfer and Flow Characteristics in a Sinusoidally Curved Converging-diverging Channel. International Journal of Thermal Sciences 148, 106163.
• 23.Chen, T.Y., Du, R.K., 2003. Effects of Velocity Fluctuations on Heat Transfer Enhancement. Experiments in Fluids, 34, 548-555