Abstract
A numerical study of vortex-induced rotations (VIRs) of an equivalent triangular cylinder, which is free to rotate in the azimuthal direction in a uniform flow, is presented. Based on an immersed boundary method, the numerical model is established, and is verified through the benchmark problem of flow past a freely rotating rectangular body. The computation is performed for a fixed reduced mass of m*=2.0 and the structural stiffness and damping ratio are set to zero. The effects of Reynolds number (Re=25–180) on the characteristics of VIR are studied. It is found that the dynamic response of the triangular cylinder exhibits four distinct modes with increasing Re: a rest position, periodic rotational oscillation, random rotation and autorotation. For the rotational oscillation mode, the cylinder undergoes a periodic vibration around an equilibrium position with one side facing the incoming flow. Since the rotation effect, the outset of vortex shedding from cylinder shifts to a much lower Reynolds number. Further increase in Re leads to 2P and P+S vortex shedding modes besides the typical 2S pattern. Our simulation results also elucidate that the free rotation significantly changes the drag and lift forces. Inspired by these facts, the effect of free rotation on flow-induced vibration of a triangular cylinder in the in-line and transverse directions is investigated. The results show that when the translational vibration is coupled with rotation, the triangular cylinder presents a galloping response instead of vortex-induced vibration (VIV).
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Alawadhi, E.M., 2013. Numerical simulation of fluid flow past an oscillating triangular cylinder in a channel, Journal of Fluids Engineering, 135(4), 041202.
Alonso, G., Sanz-Lobera, A. and Meseguer, J., 2012. Hysteresis phenomena in transverse galloping of triangular cross-section bodies, Journal of Fluids and Structures, 33, 243–251.
De, A.K. and Dalal, A, 2006. Numerical simulation of unconfined flow past a triangular cylinder, International Journal for Numerical Methods in Fluids, 52(7), 801–821.
Hübner, B., Walhorn, E. and Dinkier, D., 2001. Strongly coupled analysis of fluid-structure interaction using space-time finite elements, Proceedings of the Second European Conference on Computational Mechanics, Cracow, Poland, pp. 546–547.
Iungo, G.V. and Buresti, G., 2009. Experimental investigation on the aerodynamic loads and wake flow features of low aspect-ratio triangular prisms at different wind directions, Journal of Fluids and Structures, 25(7), 1119–1135.
Ji, C., Munjiza, A., Avital, E., Ma, J. and Williams, J.J.R., 2013. Direct numerical simulation of sediment entrainment in turbulent channel flow, Physics of Fluids, 25(5), 056601.
Ji, C., Munjiza, A. and Williams, J.J.R., 2012. A novel iterative directforcing immersed boundary method and its finite volume applications, Journal of Computational Physics, 231(4), 1797–1821.
Li, L., Sherwin, S.J. and Bearman, P.W., 2002. A moving frame of reference algorithm for fluid/structure interaction of rotating and translating bodies, International Journal for Numerical Methods in Fluids, 38(2), 187–206.
Lu, L., Guo, X.L., Tang, G.Q., Liu, M.M., Chen, C.Q. and Xie, Z.H., 2016. Numerical investigation of flow-induced rotary oscillation of circular cylinder with rigid splitter plate, Physics of Fluids, 28(9), 093604.
Lugt, H.J., 1980. Autorotation of an elliptic cylinder about an axis perpendicular to the flow, Journal of Fluid Mechanics, 99(4), 817–840.
Lugt, H.J., 1983. Autorotation, Annual Review of Fluid Mechanics, 15, 123–147.
Maxwell, J.C., 1853. On a particular case of the descent of a heavy body in a resisting medium, Cambridge and Dublin Mathematics Journal, 9, 115–118.
Mittal, R., Seshadri, V. and Udaykumar, H.S., 2004. Flutter, tumble and vortex induced autorotation, Theoretical and Computational Fluid Dynamics, 17(3), 165–170.
Newmark, N.M., 1959. A method of computation for structural dynamics, Journal of the Engineering Mechanics Division, 85(3), 67–94.
Peskin, C.S., 1972. Flow patterns around heart valves: a numerical method, Journal of Computational Physics, 10(2), 252–271.
Riabouchinsky, D.P., 1935. Thirty years of theoretical and experimental research in fluid mechanics, The Aeronautical Journal, 39(292), 282–348.
Ryu, S. and Iaccarino, G., 2017. Vortex-induced rotations of a rigid square cylinder at low Reynolds numbers, Journal of Fluid Mechanics, 813, 482–507.
Srigrarom, S., 2003. Self-excited oscillation of equilateral triangular cylinder. Proceedings of the IUTAM Symposium on Fluid-Structure Interactions, New Brunswick, New Jersey, pp. 145–158.
Srigrarom, S. and Koh, A.K.G., 2008. Flow field of self-excited rotationally oscillating equilateral triangular cylinder, Journal of Fluids and Structures, 24(5), 750–755.
Tatsuno, M., Takayama, T., Amamoto, H. and Ishi-i, K., 1990. On the stable posture of a triangular or a square cylinder about its central axis in a uniform flow, Fluid Dynamics Research, 6(3–4), 201–207.
Thomas, T.G. and Williams, J.J.R., 1997. Development of a parallel code to simulate skewed flow over a bluff body, Journal of Wind Engineering and Industrial Aerodynamics, 67–68, 155–167.
Tu, J.H., Zhou, D., Bao, Y., Han, Z.L. and Li, R.D., 2014. Flow characteristics and flow-induced forces of a stationary and rotating triangular cylinder with different incidence angles at low Reynolds numbers, Journal of Fluids and Structures, 45, 107–123.
Wang, H.K., Zhai, Q. and Chen, K.X., 2019. Vortex-induced vibrations of an elliptic cylinder with both transverse and rotational degrees of freedom, Journal of Fluids and Structures, 84, 36–55.
Wang, H.K., Zhao, D.L., Yang, W.Y. and Yu, G.L., 2015. Numerical investigation on flow-induced vibration of a triangular cylinder at a low Reynolds number, Fluid Dynamics Research, 47(1), 015501.
Zaki, T.G., Sen, M. and Gad-El-Hak, M., 1994. Numerical and experimental investigation of flow past a freely rotatable square cylinder, Journal of Fluids and Structures, 8(7), 555–582.
Zhu, H.J. and Lin, P.Z., 2018. Numerical simulation of the vortex-induced vibration of a curved flexible riser in shear flow, China Ocean Engineering, 32(3), 301–311.
Zhu, H.J., Zhao, Y. and Zhou, T.M., 2018. Numerical investigation of the vortex-induced vibration of an elliptic cylinder free-to-rotate about its center, Journal of Fluids and Structures, 83, 133–155.
Zielinska, B.J.A. and Wesfreid, J.E., 1995. On the spatial structure of global modes in wake flow, Physics of Fluids, 7(6), 1418–1424.
Author information
Authors and Affiliations
Corresponding authors
Additional information
Foundation item: This study was financially supported by the Fundamental Research Funds for the Central Universities (Grant Nos. 2018B56414 and 2019B12014) and the National Natural Science Foundation of China (Grant No. 51609077).
Rights and permissions
About this article
Cite this article
Wang, Hk., Yan, Yh., Chen, Cm. et al. Numerical Investigation on Vortex-Induced Rotations of A Triangular Cylinder Using An Immersed Boundary Method. China Ocean Eng 33, 723–733 (2019). https://doi.org/10.1007/s13344-019-0070-0
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s13344-019-0070-0