Wind and Structures

Techno-Press (테크노프레스)
권호 표지
DOI QR코드

DOI QR Code

Aerodynamics of a cylinder in the wake of a V-shaped object

  • Kim, Sangil (Department of Mechanical Engineering, Kangwon National University) ;
  • Alam, Md. Mahbub (Institute for Turbulence-Noise-Vibration Interaction and Control, Shenzhen Graduate School, Harbin Institute of Technology) ;
  • Russel, Mohammad (School of Food and Environment, Key laboratory of Industrial Ecology and Environmental Engineering, Ministry of Education, Dalian University of Technology)
  • Received : 2016.03.03
  • Accepted : 2016.06.19
  • Published : 2016.08.25
⟨ Previous Next ⟩

Abstract

The interaction between two different shaped structures is very important to be understood. Fluid-structure interactions and aerodynamics of a circular cylinder in the wake of a V-shaped cylinder are examined experimentally, including forces, shedding frequencies, lock-in process, etc., with the V-shaped cylinder width d varying from d/D = 0.6 to 2, where D is the circular cylinder diameter. While the streamwise separation between the circular cylinder and V-shaped cylinder was 10D fixed, the transverse distance T between them was varied from T/D = 0 to 1.5. While fluid force and shedding frequency of the circular cylinder were measured using a load cell installed in the circular cylinder, measurement of shedding frequency of the V-shaped cylinder was done by a hotwire. The major findings are: (i) a larger d begets a larger velocity deficit in the wake; (ii) with increase in d/D, the lock-in between the shedding from the two cylinders is centered at d/D = 1.1, occurring at $d/D{\approx}0.95-1.35$ depending on T/D; (iii) at a given T/D, when d/D is increased, the fluctuating lift grows and reaches a maximum before decaying; the d/D corresponding to the maximum fluctuating lift is dependent on T/D, and the relationship between them is linear, expressed as $d/D=1.2+{\frac{1}{e}}T/D$; that is, a larger d/D corresponds to a greater T/D for the maximum fluctuating lift.

Keywords

Acknowledgement

Supported by : Kangwon National University

References

  1. Alam, M.M. (2014), "The aerodynamics of a cylinder submerged in the wake of another", J. Fluid. Struct., 51, 393-400. https://doi.org/10.1016/j.jfluidstructs.2014.08.003
  2. Alam, M.M. and Kim, S. (2009), "Free vibration of two identical circular cylinders in staggered arrangement", Fluid Dynam. Research, 41(3), 035507. https://doi.org/10.1088/0169-5983/41/3/035507
  3. Alam, M.M., Moriya, M., Takai, K. and Sakamoto, H. (2003), "Fluctuating fluid forces acting on two circular cylinders in a tandem arrangement at a subcritical Reynolds number", J. Wind Eng. Ind. Aerod., 91, 139-154. https://doi.org/10.1016/S0167-6105(02)00341-0
  4. Dehkordi, B.G., Moghaddam H.S. and Jafari, H.H. (2011) "Numerical simulation of flow over two circular cylinders in tandem arrangement", J. Hydrodynamics, 23(1), 114-126. https://doi.org/10.1016/S1001-6058(10)60095-9
  5. Griffin, O.M. and Ramberg, S.E. (1974), "The vortex-street wakes of vibrating cylinders", J. Fluid Mech., 66(3), 553-576. https://doi.org/10.1017/S002211207400036X
  6. Haniu, H., Kim, S., Miyakoshi, K., Takai, K. and Islam, M.R. (2009), "Transitional characteristics of phase shift in lock-in phenomena of an oscillating cylinder", J. Fluid Sci. Technol., 4(3), 479-489. https://doi.org/10.1299/jfst.4.479
  7. Kim, S., Alam, M.M, Sakamoto, H. and Zhou, Y. (2009a), "Flow-induced vibration of two circular cylinders in tandem arrangement. Part 1: characteristics of vibration", J. Wind Eng. Ind. Aerod., 97(5-6), 304-311. https://doi.org/10.1016/j.jweia.2009.07.004
  8. Kim, S., Alam, M.M, Sakamoto, H. and Zhou, Y. (2009b), "Flow-induced vibration of two circular cylinders in tandem arrangement. Part 2: suppression of vibrations", J. Wind Eng. Ind. Aerod., 97(5-6), 312-319. https://doi.org/10.1016/j.jweia.2009.07.003
  9. Kim, S. and Alam, M.M. (2015), "Characteristics and suppression of flow-induced vibrations of two side-by-side circular cylinders", J. Fluid. Struct., 54, 629-642. https://doi.org/10.1016/j.jfluidstructs.2015.01.004
  10. Lam, K.M. and To, A.P. (2003), "Interference effect of an upstream larger cylinder on the lock-in vibration of a flexibly mounted circular cylinder", J. Fluid. Struct., 17(8), 1059-1078. https://doi.org/10.1016/S0889-9746(03)00065-3
  11. Mahir, N. and Rockwell, D. (1996), "Vortex formation from a forced system of two cylinders. Part I: tandem arrangement", J. Fluid. Struct., 10(5), 473-489. https://doi.org/10.1006/jfls.1996.0032
  12. Rahmanian, M., Cheng, L., Zhao, M. and Zhou, T. (2014), "Vortex-induced vibration and vortex shedding characteristics of two side-by-side circular cylinders of different diameters in close proximity in steady flow", J. Fluid. Struct., 48, 260-279. https://doi.org/10.1016/j.jfluidstructs.2014.03.004
  13. Sumner, D., Price, S.J. and Paidoussis, M.P. (2000), "Flow-pattern identification for two staggered circular cylinders in cross-flow", J. Fluid Mech., 411, 263-303. https://doi.org/10.1017/S0022112099008137

Cited by

  1. Enhancing aerodynamic performance of NACA 4412 aircraft wing using leading edge modification vol.29, pp.4, 2019, https://doi.org/10.12989/was.2019.29.4.271
  2. Aerodynamic design optimization of an aircraft wing for drag reduction using computational fluid dynamics approach vol.31, pp.1, 2020, https://doi.org/10.12989/was.2020.31.1.15