Wind and Structures

  • 제31권3호
  • /
  • Pages.255-267
  • /
  • 2020
  • /
  • 1226-6116(pISSN)
  • /
  • 1598-6225(eISSN)
테크노프레스 (Techno-Press)
권호 표지
DOI QR코드

DOI QR Code

Wind loading of a finite prism: aspect ratio, incidence and boundary layer thickness effects

  • Heng, Herman (Department of Mechanical Engineering, University of Saskatchewan) ;
  • Sumner, David (Department of Mechanical Engineering, University of Saskatchewan)
  • 투고 : 2019.09.05
  • 심사 : 2020.03.09
  • 발행 : 2020.09.25
⟨ 이전 논문 다음 논문 ⟩

초록

A systematic set of low-speed wind tunnel experiments was performed at Re = 6.5×104 and 1.1×105 to study the mean wind loading experienced by surface-mounted finite-height square prisms for different aspect ratios, incidence angles, and boundary layer thicknesses. The aspect ratio of the prism was varied from AR = 1 to 11 in small increments and the incidence angle was changed from α = 0° to 45° in increments of 1°. Two different boundary layer thicknesses were used: a thin boundary layer with δ/D = 0.8 and a thick boundary layer with δ/D = 2.0-2.2. The mean drag and lift coefficients were strong functions of AR, α, and δ/D, while the Strouhal number was mostly influenced by α. The critical incidence angle, at which the prism experiences minimum drag, maximum lift, and highest vortex shedding frequency, increased with AR, converged to a value of αc = 18° ± 2° once AR was sufficiently high, and was relatively insensitive to changes in δ/D. A local maximum value of mean drag coefficient was identified for higher-AR prisms at low α. The overall behaviour of the force coefficients and Strouhal number with AR suggests the possibility of three flow regimes.

키워드

과제정보

Financial support from the NSERC Discovery Grants program (Grant No. 2018-03760), the College of Engineering's Graduate Research Fellowship program, and the Department of Mechanical Engineering's Graduate Scholarships program, is gratefully acknowledged. The technical assistance of Shawn Reinink, Rob Peace, and Engineering Shops is also recognized.

참고문헌

  1. Akins, R.E., Peterka, J.A. and Cermak, J.E. (1977), "Mean force and moment coefficients for buildings in turbulent boundarylayers", J Wind Eng. Ind Aerod., 2(3), 195-209. https://doi.org/10.1016/0167-6105(77)90022-8.
  2. Bai, H.L. and Alam, M.M. (2018), "Dependence of square cylinder wake on Reynolds number", Phys Fluids, 30(1), 015102. https://doi.org/10.1063/1.4996945.
  3. Behera, S. and Saha, A.K. (2019), "Characteristics of the flow past a wall-mounted finite-length square cylinder at low Reynolds number with varying boundary layer thickness", J. Fluid Eng. 141(6), https://doi.org/10.1115/1.4042751.
  4. Beitel, A., Heng, H. and Sumner, D. (2019), "The effect of aspect ratio on the aerodynamic forces and bending moment for a surface-mounted finite-height cylinder", J Wind Eng. Ind. Aerod., 186, 204-213. https://doi.org/10.1016/j.jweia.2019.01.009.
  5. Cao, Y., Tamura, T. and Kawai, H. (2019), "Investigation of wall pressures and surface flow patterns on a wall-mounted square cylinder using very high-resolution Cartesian mesh", J. Wind Eng. Ind. Aerod., 188, 1-18. https://doi.org/10.1016/j.jweia.2019.02.013.
  6. El Hassan, M., Bourgeois, J. and Martinuzzi, R. (2015), "Boundary layer effect on the vortex shedding of wall-mounted rectangular cylinder", Exp Fluids, 56(2), https://doi.org/10.1007/s00348-014-1882-6.
  7. Fox, T.A. and West, G.S. (1993), "Fluid-induced loading of cantilevered circular cylinders in a low-turbulence uniform flow. Part 1: Mean loading with aspect ratios in the range 4 to 30", J. Fluid Struct., 7(1), 1-14. https://doi.org/10.1006/jfls.1993.1001.
  8. Hosseini, Z., Bourgeois, J.A. and Martinuzzi, R.J. (2013), "Largescale structures in dipole and quadrupole wakes of a wallmounted finite rectangular cylinder", Exp Fluids, 54(9). https://doi.org/10.1007/s00348-013-1595-2.
  9. Igarashi, T. (1984), "Characteristics of the flow around a square prism", B JSME, 27(231), 1858-1865. https://doi.org/10.1299/jsme1958.27.1858.
  10. Kindree, M.G., Shahroodi, M. and Martinuzzi, R.J. (2018), "Lowfrequency dynamics in the turbulent wake of cantilevered square and circular cylinders protruding a thin laminar boundary layer", Exp Fluids, 59(12), 186. https://doi.org/10.1007/s00348-018-2641-x.
  11. Knisely, C.W. (1990), "Strouhal numbers of rectangular cylinders at incidence - a review and new data", J. Fluid Struct., 4(4), 371-393. https://doi.org/10.1016/0889-9746(90)90137-T
  12. Lee, B.E. (1975), "The effect of turbulence on surface pressure field of a square prism", J Fluid Mech., 69(2), 263-282. https://doi.org/10.1017/S0022112075001437
  13. Lee, Y.T., Boo, S.I., Lim, H.C. and Misutani, K. (2016), "Pressure distribution on rectangular buildings with changes in aspect ratio and wind direction", Wind Struct, 23(5), 465-483. http://dx.doi.org/10.12989/was.2016.23.5.465.
  14. Lim, H.C. (2009), "Wind flow around rectangular obstacles with aspect ratio", Wind Struct, 12(4), 299-312. https://doi.org/10.12989/was.2009.12.4.299.
  15. McClean, J.F. and Sumner, D. (2014), "An experimental investigation of aspect ratio and incidence angle effects for the flow around surface-mounted finite-height square prisms", J Fluid Eng., 136(8). https://doi.org/10.1115/1.4027138.
  16. Moreau, D.J. and Doolan, C.J. (2013), "Flow-induced sound of wall-mounted finite length cylinders", AIAA J., 51(10), 2493-2502. https://doi.org/10.2514/1.J052391.
  17. Natarajan, V. and Chyu, M.K. (1994), "Effect of flow angle-ofattack on the local heat mass-transfer from a wall-mounted cube", J Heat Trans., 116(3), 552-560. https://doi.org/10.1115/1.2910906.
  18. Norberg, C. (1993), "Flow around rectangular cylinders - pressure forces and wake frequencies". J. Wind Eng. Ind. Aerod., 49(1-3), 187-196. https://doi.org/10.1016/0167-6105(93)90014-F.
  19. Obasaju, E.D. (1983), "An investigation of the effects of incidence on the flow around a square section cylinder", Aeronaut Quart, 34(4), 243-259. https://doi.org/10.1017/S0001925900009768.
  20. Okuda, Y. and Taniike, Y. (1993), "Conical vortices over side face of a three-dimensional square prism", J. Wind Eng. Ind. Aerod., 50, 163-172. https://doi.org/10.1016/0167-6105(93)90071-U.
  21. Porteous, R., Moreau, D.J. and Doolan, C.J. (2017), "The aeroacoustics of finite wall-mounted square cylinders", J. Fluid Mech., 832, 287-328. https://doi.org/10.1017/jfm.2017.682.
  22. Saha, A.K. (2013), "Unsteady flow past a finite square cylinder mounted on a wall at low Reynolds number", Comput. Fluids, 88(15), 599-615. https://doi.org/10.1016/j.compfluid.2013.10.010.
  23. Sakamoto, H. (1985), "Aerodynamic forces acting on a rectangular prism placed vertically in a turbulent boundarylayer", J. Wind Eng. Ind. Aerod., 18(2), 131-151. https://doi.org/10.1016/0167-6105(85)90093-5.
  24. Sakamoto, H. and Arie, M. (1983), "Vortex shedding from a rectangular prism and a circular-cylinder placed vertically in a turbulent boundary-layer", J. Fluid Mech., 126, 147-165. https://doi.org/10.1017/S0022112083000087.
  25. Sakamoto, H. and Oiwake, S. (1984), "Fluctuating forces on a rectangular prism and a circular-cylinder placed vertically in a turbulent boundary-layer", J. Fluid Eng. Trans., 106(2), 160-166. https://doi.org/10.1115/1.3243093.
  26. Sarode, R.S., Gai, S.L. and Ramesh, C.K. (1981), "Flow around circular-section and square-section models of finite height in a turbulent shear-flow", J. Wind Eng. Ind. Aerod., 8(3), 223-230. https://doi.org/10.1016/0167-6105(81)90022-2.
  27. Sohankar, A., Esfeh, M.K., Pourjafari, H., Alam, M.M. and Wang, L.J. (2018), "Features of the flow over a finite length square prism on a wall at various incidence angles", Wind Struct, 26(5), 317-329. https://doi.org/10.12989/was.2018.26.5.317.
  28. Sumner, D., Rostamy, N., Bergstrom, D.J. and Bugg, J.D. (2017), "Influence of aspect ratio on the mean flow field of a surfacemounted finite-height square prism", Int. J. Heat Fluid Flow, 65, 1-20. https://doi.org/10.1016/j.ijheatfluidflow.2017.02.004.
  29. Unnikrishnan, S., Ogunremi, A. and Sumner, D. (2017), "The effect of incidence angle on the mean wake of surface-mounted finite-height square prisms", Int J Heat Fluid Fl, 66, 137-156. https://doi.org/10.1016/j.ijheatfluidflow.2017.05.012
  30. Wang, H., Zhou, Y., Chan, C. and Zhou, T. (2009), "Momentum and heat transport in a finite-length cylinder wake", Exp Fluids, 46(6), 1173-1185. https://doi.org/10.1007/s00348-009-0620-y.
  31. Wang, H.F. and Zhou, Y. (2009), "The finite-length square cylinder near wake", J. Fluid Mech., 638, 453-490. https://doi.org/10.1017/S0022112009990693.
  32. Wang, H.F., Zhao, X.Y., He, X.H. and Yu, Z. (2017), "Effects of oncoming flow conditions on the aerodynamic forces on a cantilevered square cylinder", J. Fluid Struct., 75, 140-157. https://doi.org/10.1016/j.jfluidstructs.2017.09.004.
  33. Wang, H.F., Zhou, Y., Chan, C.K. and Lam, K.S. (2006), "Effect of initial conditions on interaction between a boundary layer and a wall-mounted finite-length-cylinder wake", Phys. Fluids, 18(6), 065106. doi:10.1063/1.2212329
  34. Wang, Y.Q. (2019), "Effects of Reynolds number on vortex structure behind a surface-mounted finite square cylinder with AR = 7", Phys Fluids, 31(11), 115103. https://doi.org/10.1063/1.5123994.
  35. Yauwenas, Y., Porteous, R., Moreau, D.J. and Doolan, C.J. (2019), "The effect of aspect ratio on the wake structure of finite wallmounted square cylinders", J. Fluid Mech., 875, 929-960. https://doi.org/10.1017/jfm.2019.522.
  36. Yen, S.C. and Yang, C.W. (2011), "Flow patterns and vortex shedding behavior behind a square cylinder", J. Wind Eng. Ind. Aerod., 99(8), 868-878. https://doi.org/10.1016/j.jweia.2011.06.006.
  37. Zhang, D., Cheng, L., An, H.W. and Zhao, M. (2017), "Direct numerical simulation of flow around a surface-mounted finite square cylinder at low Reynolds numbers", Phys Fluids, 29(4), 045101. https://doi.org/10.1063/1.4979479.