Numerical Analysis of the Flow Structure around Inclined Solid Cylinder and Its Effect on Bed Shear Stress Distribution

Document Type : Regular Article


Alanya University, Civil Engineering Department, Alanya, Antalya, Turkey



The flow-inclined cylinder interaction is an application area in the industry (i.e., offshore wind turbines and pile-supported near-shore structures). Findings of recent studies have revealed the significance of eco-friendly coastal structures that needs the utilization of inclined cylinder. The primary purpose of this study was to better understand the influence of inclination on flow, turbulence, and bed shear stress character. To achieve this objective, a three-dimensional numerical code (the Reynolds-averaged Navier-Stokes model) was used. The numerical model was calibrated based on eleven velocity profiles obtained by point measurements data of the wake region of the inclined cylinder. The mean flow, turbulence, and secondary flow characteristics around the bodies were extensively investigated, particularly at points where experimental measurements are inapplicable with intrusive turbulence measurement devices. The findings of the study revealed that as the inclination of the cylinder increased, the coherent structures that largely control the flow dynamics in the wake zone became stable rather than cyclical. Specifically, it was determined that although vorticity couples underpinned the flow field behind the vertical cylinder, large-scale streamwise vortices replaced the visible coherent structures when the cylinders were inclined (LSCSVs). When the cylinder inclined 42 degrees, the reduction in amplification factor (τ0 / τ∞) over the bed was roughly fifty percent in terms of quantity. This finding shows that inclination is a streamlined form for a cylinder and may reduce the collapse risk due to scour.


Main Subjects

Acanal, L., Loukogeorgaki, E., Yagci, O., Kirca, V. S. O., & Akgul, A. (2013). Performance of an inclined thin plate in wave attenuation. Journal of Coastal Research, 65 (10065), 141–146
Baykal, C., Sumer, B. M., Fuhrman, D. R., Jacobsen, N. G., & Fredsøe, J. (2015). Numerical investigation of flow and scour around a vertical circular cylinder. Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 373(2033), 20140104.
Bozkus, Z., & Yildiz, O. (2004). Effects of inclination of bridge piers on scouring depth. Journal of Hydraulic Engineering, 130(8), 827–832.
Chang, K., & Constantinescu, G. (2015). Numerical investigation of flow and turbulence structure through and around a circular array of rigid cylinders. Journal of Fluid Mechanics, 776, 161–199.
Chiatto, M., Shang, J. K., De Luca, L., & Grasso, F., (2021). Insights into low reynolds flow past finite curved cylinders. Physics of Fluids, 33(3).
Choi, S. U., & Choi, B. (2016). Prediction of time-dependent local scour around bridge piers. Water and Environment Journal, 30, n/a-n/a.
Ettema, R., Melville, B. W., & Barkdoll, B. (1998). Scale effect in pier-scour experiments. Journal of Hydraulic Engineering, 124(6), 639–642.
Euler, T., Zemke, J., Rodrigues, S., & Herget, J. (2014). Influence of inclination and permeability of solitary woody riparian plants on local hydraulic and sedimentary processes. Hydrological Processes, 28(3), 1358–1371.
Flowscience (2019). Flow-3D User Manual.##
Graf, W. H. & Istiarto, I. (2002) Flow pattern in the scour hole around a cylinder, Journal of Hydraulic Research, 40(1), 13-20,
Istiarto, I. (2001). Flow Around a Cylinder in a Scoured Channel Bed. Gadjah Mada University.##
Jiang, F., Pettersen, B., Andersson, H. I., Kim, J., & Kim, S. (2018). Wake behind a concave curved cylinder. Physical Review Fluids, 3(9), 94804.
Jiang, F., Pettersen, B., & Andersson, H. I. (2019). Turbulent wake behind a concave curved cylinder. Journal of Fluid Mechanics, 878, 663–99.
Kazemi, A. (2017). Hydrodynamics of mangrove root-type models (Issue December). Florida Atlantic University.##
Keshavarzi, A., Shrestha, C., Ranjbar Zahedani, M., Ball, J., & Khabbaz, H. (2017). Experimental study of flow structure around two in-line bridge piers. Proceedings of the Institution of Civil Engineers - Water Management, 171, 1–17.
Kitsikoudis, V., Kirca, V. S. O., Yagci, O., & Celik, M. F. (2017). Clear water scour and flow field alteration around an inclined pile. Coastal Engineering, 129, 59–73.
Larsen, B. E., Fuhrman, D. R., & Sumer, B. M. (2016). Simulation of wave-plus-current scour beneath submarine pipelines. Journal of Waterway, Port, Coastal, and Ocean Engineering, 142(5), 04016003.
Majd, F. S., Yagci, O., Kirca, V. S. O., Kitsikoudis, V., & Lentsiou, E. N. (2016). Flow and turbulence around an inclined pile. Twenty-Sixth (2016) International Ocean and Polar Engineering Conference.##
Minor, M., Zimmer, M., Helfer, V., Gillis, L., & Huhn, K. (2021). Flow and sediment dynamics around structures in mangrove ecosystems—a modeling perspective (pp. 83–120).
Moffatt, H. K. (1969). The degree of knottedness of tangled vortex lines. Journal of Fluid Mechanics, 35(1), 117–129.
Moffatt, H. K., & Tsinober, A. (1992). Helicity in laminar and turbulent flow. Annual Review of Fluid Mechanics, 24(1), 281–312.
Moreau, J. J. (1961). Constantes d’un îlot tourbillonnaire en fluide parfait barotrope. Comptes Rendus Hebdomadaires Des Séances de l’Académie Des Sciences, 252(19), 2810.##
Munson, B. R., Okiishi, T. H., Young, D. F. (2002) Fundamentals of Fluid Mechanics. 4th Edition, R. R. Donnelley & Sons, Chicago.##
Nieuwstadt, F. T. M., Westerweel, J., & Boersma, B. J. (2016). Turbulence. Springer International Publishing.
Norberg, C. (1994). An experimental investigation of the flow around a circular cylinder: Influence of aspect ratio. Journal of Fluid Mechanics, 258(April), 287–316.
Rajani, B.N., Kandasamy, A., & Majumdar, S. (2012). On the reliability of eddy viscosity based turbulence models in predicting turbulent flow past a
circular cylinder using URANS approach.
Journal of Applied Fluid Mechanics, 5.
Rosa, R. M. S. (2006). Turbulence Theories. Academic Press.
Roulund, A., Sumer, B. M., Fredsøe, J., & Michelsen, J. (2005a). Numerical and experimental investigation of flow and scour around a circular pile. Journal of Fluid Mechanics, 534, 351–401.
Roulund, A., Sumer, B. M., Fredsøe, J., & Michelsen, J. (2005b). Numerical and experimental investigation of flow and scour around a circular pile. Journal of Fluid Mechanics, 534, 351–401.
Shang, J. K., Stone, H. A., & Smits, A. J. (2018). Flow past finite cylinders of constant curvature. Journal of Fluid Mechanics, 837, 896–915.
Sumer, B. M., & Fredsøe, J. (2006). Hydrodynamics Around Cylindrical Structures. Advanced Series on Ocean Engineering (Vol. 26). WORLD SCIENTIFIC.
Sumner, D. (2010). Two circular cylinders in crossflow: A review. Journal of Fluids and Structures, 26(6), 849–899.
Surry, J., & Surry, D. (1967). The Effect of Inclination on the Strouhal Number and Other Wake Properties of Circular Cylinders at Subcritical Reynolds Numbers. University of Toronto. Institute for Aerospace Studies.##
Tesař, V. (2005). Time-mean helicity distribution in turbulent swirling jets. Acta Polytechnica, 45(6).
Unger, J., & Hager, W. H. (2006). Down-flow and horseshoe vortex characteristics of sediment embedded bridge piers. Experiments in Fluids, 42(1), 1–19.
Wang, S., Yang, S., He, Z., Li, L., & Xia, Y. (2020). Effect of inclination angles on the local scour around a submerged cylinder. Water (Switzerland), 12(10), 1–20.
Yagci, O., Celik, M. F., Kitsikoudis, V., Ozgur Kirca, V. S., Hodoglu, C., Valyrakis, M., Duran, Z., & Kaya, S. (2016). Scour patterns around isolated vegetation elements. Advances in Water Resources, 97, 251–265.
Yagci, O., Kirca, V. S. O., & Acanal, L. (2014). Wave attenuation and flow kinematics of an inclined thin plate acting as an alternative coastal protection structure. Applied Ocean Research, 48, 214–226.
Yagci, O., Yildirim, I., Celik, M. F., Kitsikoudis, V., Duran, Z., & Kirca, V. S. O. (2017). Clear water scour around a finite array of cylinders. Applied Ocean Research, 68, 114–129.
Yamamoto, K., & Hosokawa, I. (1981). A numerical study of inviscid helical turbulence. Journal of the Physical Society of Japan, 50(1), 343–348.
Yu, X. (2002). Functional performance of a submerged and essentially horizontal plate for offshore wave control: A Review. Coastal Engineering Journal, 44(2), 127–147.
Zimmerman, W. B. (1996). Fluctuations in passive tracers due to mixing by coherent structures in isotropic, homogeneous, helical turbulence. IChemE Symposium Series, 213–224.##