Wind and Structures

  • 제37권2호
  • /
  • Pages.163-178
  • /
  • 2023
  • /
  • 1226-6116(pISSN)
  • /
  • 1598-6225(eISSN)
테크노프레스 (Techno-Press)
권호 표지
DOI QR코드

DOI QR Code

Updates to the wind tunnel method for determining design loads in ASCE 49-21

  • Gregory A. Kopp (Boundary Layer Wind Tunnel Laboratory, Faculty of Engineering, Western University)
  • 투고 : 2022.12.13
  • 심사 : 2023.07.05
  • 발행 : 2023.08.25
⟨ 이전 논문 다음 논문 ⟩

초록

The paper reviews and discusses the substantive changes to the ASCE 49-21 Standard, Wind Tunnel Testing for Buildings and Other Structures. The most significant changes are the requirements for wind field simulations that utilize (i) partial turbulence simulations, (ii) partial model simulations for the flow around building Appurtenances, along with requirements for determining wind loads on products that are used at multiple sites in various configurations. These modifications tend to have the effect of easing the precise scaling requirements for flow simulations because it is not generally possible to construct accurate models for small elements placed, for example, on large buildings at the scales typically available in boundary layer wind tunnels. Additional discussion is provided on changes to the Standard with respect to measurement accuracy and data acquisition parameters, such as duration of tests, which are also related to scaling requirements. Finally, research needs with respect to aerodynamic mechanisms are proposed, with the goal of improving the understanding of the role of turbulence on separated-reattaching flows on building surfaces in order to continue to improve the wind tunnel method for determining design wind loads.

키워드

과제정보

While the author has summarized some of the rationale used by the committee in the development of ASCE 49-21 (2021), the opinions and analysis expressed herein are those of the author. The actual ASCE 49 document provides the official consensus of the committee. The author is grateful to the entire committee for many interesting and fruitful discussions on the topics examined herein, but particularly with Drs. D. Banks, G. Bitsuamlak, P. Irwin, C. Letchford, M. Morrison, J. Wang, and Mr. T. Geleta. The author is also grateful for the financial support provided by ImpactWX.

참고문헌

  1. Akon, A.F. (2017), Effects of turbulence on the separating-reattaching flow above surface-mounted, three-dimensional bluff bodies, PhD Thesis, University of Western Ontario, Canada. https://ir.lib.uwo.ca/etd/4445.
  2. Akon, A.F. and Kopp, G.A. (2016), "Mean pressure distributions and reattachment lengths for roof-separation bubbles on low-rise buildings", J. Wind Eng. Ind. Aerod., 155, 115-125. https://doi.org/10.1016/j.jweia.2016.05.008.
  3. Akon, A.F. and Kopp, G.A. (2018), "Turbulence structure and similarity in the separated flow above a low building in the atmospheric boundary layer", J. Wind Eng. Ind. Aerod., 182, 87-100. https://doi.org/10.1016/j.jweia.2018.09.016.
  4. ASCE (1999), Wind Tunnel Studies of Buildings and Structures, ASCE MOP 67, American Society of Civil Engineers; Reston, VA, USA. https://doi.org/10.1061/9780784403198.
  5. ASCE (2012), Wind Tunnel Testing for Buildings and Other Structures, ASCE 49-12, American Society of Civil Engineers; Reston, VA, USA. https://doi.org/10.1061/9780784412282.
  6. ASCE (2017), Minimum Design Loads and Associated Criteria for Building and Other Structures, ASCE 7-16, American Society of Civil Engineers; Reston, VA, USA. https://doi.org/10.1061/9780784414248.
  7. ASCE (2021), Wind Tunnel Testing for Buildings and Other Structures, ASCE 49-21, American Society of Civil Engineers; Reston, VA, USA. https://doi.org/10.1061/9780784415740.
  8. ASCE (2022), Minimum design loads and associated criteria for building and other structures, ASCE 7-22, American Society of Civil Engineers; Reston, VA, USA. https://doi.org/10.1061/9780784415788.
  9. Asghari-Mooneghi, M., Irwin, P. and Gan Chowdhury, A. (2016), "Partial turbulence simulation method for predicting peak wind loads on small structures and building appurtenances", J. Wind Eng. Ind. Aerod., 157, 47-62. https://doi.org/10.1016/j.jweia.2016.08.003.
  10. Baker, C.J. (1979), "The laminar horseshoe vortex", J. Fluid Mech., 95(2), 347-367. https://doi.org/10.1017/S0022112079001506.
  11. Banks, D. (2011), "Measuring peak wind loads on solar power assemblies", Proceedings of the 13th International Conference of Wind Engineering, Amsterdam, the Netherlands, July.
  12. Banks, D. (2013), "The role of corner vortices in dictating peak wind loads on tilted flat solar panels mounted on large, flat roofs", J. Wind Eng. Ind. Aerod., 123, 192-201. https://doi.org/10.1016/j.jweia.2013.08.015.
  13. Birhane, T.H., Bitsuamlak, G.T., Kahsay, M.T. and Awol, A.D. (2020), "Air-permeability factor for wind loads on loose-laid pavers on flat roofs", J. Struct. Eng., 146(8), 04020151. https://doi.org/10.1061/(ASCE)ST.1943.
  14. ESDU (1983), Strong Winds in the Atmospheric Boundary Layer, Part 2: Discrete gust speeds. Engineering Science Data Unit 83045. London, England.
  15. Estephan, J., Chowdhury, A.G. and Irwin, P. (2022), "A new experimental-numerical approach to estimate peak wind loads on roof-mounted photovoltaic systems by incorporating inflow turbulence and dynamic effects", Eng. Struct., 252, 113739. https://doi.org/10.1016/j.engstruct.2021.113739.
  16. Gartshore, I. (1973), The effects of freestream turbulence on the drag of rectangular two-dimensional prism, University of Western Ontario BLWTL Report No. 4-73, London, Canada.
  17. Gavanski, E., Gurley, K.R. and Kopp, G.A. (2016), "Uncertainties in the estimation of local peak pressures on low-rise buildings by using the Gumbel distribution fitting approach", J. Structural Eng., 142(1), 04016106. https://doi.org/10.1061/(ASCE)ST.1943-541X.0001556.
  18. Geleta, T.N. and Bitsuamlak, G. (2022), "Validation metrics and turbulence frequency limits for LES-based wind load evaluation for low-rise buildings", J. Wind Eng. Ind. Aerod., 231, 105210. https://doi.org/10.1016/j.jweia.2022.105210.
  19. Guo, Y., Wu, C.H. and Kopp, G.A. (2021), "A method to estimate peak pressures on low-rise building models based on quasisteady theory and partial turbulence analysis", J. Wind Eng. Ind. Aerod., 218, 104785. https://doi.org/10.1016/j.jweia.2021.104785.
  20. Holmes, J.D. (2015), Wind Loading of Structures, CRC Press, Boca Raton, FL, USA. https://doi.org/10.1201/b18029.
  21. Hunt, J.C.R., Kawai, H., Ramsey, S.R., Pedrizetti, G. and Perkins, R.J. (1990), "A review of velocity and pressure fluctuations in turbulent flows around bluff bodies", J. Wind Eng. Ind. Aerod., 35, 49-85. https://doi.org/10.1016/0167-6105(90)90210-4.
  22. Irwin, P.A. (2008), "Bluff body aerodynamics in wind engineering", J. Wind Eng. Ind. Aerod., 96(6-7), 701-712. https://doi.org/10.1016/j.jweia.2007.06.008.
  23. Kawai, H. (1983), "Pressure fluctuations on square prisms - applicability of strip and quasi-steady theories", J. Wind Eng. Ind. Aerod., 13(1-3), 197-208. https://doi.org/10.1016/0167-6105(83)90141-1.
  24. Kopp, G.A. (2018), "Large-scale and full-scale methods for examining wind effects on buildings", Frontiers Media, Lausanne, https://doi.org/10.3389/978-2-88945-510-2.
  25. Kopp, G.A. and Banks, D. (2013), "Use of the wind tunnel test method for obtaining design wind loads on roof-mounted solar arrays", J. Struct. Eng., 139(2), 284-287. https://doi.org/10.3390/su14148477.
  26. Kwan, K. and Kopp, G.A. (2021), "The effects of edge radius on wind tunnel tests of low-rise buildings", J. Wind Eng. Ind. Aerod., 214, 104668. https://doi.org/10.1016/j.jweia.2021.104668.
  27. Lander, D.C., Letchford, C.W., Amitay, M. and Kopp, G.A. (2016), "Influence of the bluff body shear layers on the wake of a square prism in a turbulent flow", Phys. Rev. Fluids, 1, 044406. https://doi.org/10.1103/PhysRevFluids.1.044406. 
  28. Liang, S., Liu, S., Li, Q.S., Zhang, L. and Gu, M. (2002), "Mathematical model of across wind dynamic loads on rectangular tall buildings", J. Wind Eng. Ind. Aerod., 90(12-15), 1757-1770. https://doi.org/10.1016/S0167-6105(02)00285-4.
  29. Letchford, C.W., Iverson, R.E. and McDonald, J.R. (1993), "The application of quasi-steady theory to full scale measurements on the Texas Tech Building", J. Wind Eng. Ind. Aerod., 48, 111-132. https://doi.org/10.1016/0167-6105(93)90284-U.
  30. Lim, H.C., Castro, I.P. and Hoxey, R.P. (2007), "Bluff bodies in deep turbulent boundary layers: Reynolds-number issues", J. Fluid Mech., 571, 97-118. https://doi.org/10.1017/S0022112006003223.
  31. Melbourne, W.H. (1979), "Turbulence effects on maximum surface pressures - A mechanism and possibility of reduction", Proceedings of the 5th International Conference on Wind Engineering, Fort Collins, CO, USA, https://doi.org/10.1016/B978-1-4832-8367-8.50055-3.
  32. Moravej, M., Zisis, I., Chowdhury, A.G., Irwin, P. and Hajra, B. (2016), "Experimental assessment of wind loads on vinyl wall siding", Fron. Built Environ., 2, 35. https://doi.org/10.3389/fbuil.2016.00035.
  33. Morrison, M.J. and Kopp, G.A. (2018), "Effects of turbulence intensity and scale on surface pressure fluctuations on the roof of a low-rise building in the atmospheric boundary layer", J. Wind Eng. Ind. Aerod., 183, 140-151. https://doi.org/10.1016/j.jweia.2018.10.017.
  34. Naeiji, A., Raji, F. and Zisis, I. (2017), "Wind loads on residential scale rooftop photovoltaic panels", J. Wind Eng. Ind. Aerod., 168, 228-246. https://doi.org/10.1016/j.jweia.2017.06.006.
  35. Pratt, R.N. and Kopp, G.A. (2014), "Velocity field measurements above the roof of a low-rise building during peak suctions", J. Wind Eng. Ind. Aerod., 133, 234-241. https://doi.org/10.1016/j.jweia.2014.06.009.
  36. Reinhold, T. (1982), Wind Tunnel Modeling for Civil Engineering Applications, Cambridge University Press.
  37. Richards, P.J., Hoxey, R.P. and Wanigaratne, B.S. (1995), "The effect of directional variation on the observed mean and rms pressure coefficients", J. Wind Eng. Ind. Aerod., 5, 359-367. https://doi.org/10.1016/0167-6105(94)00067-N.
  38. Saathoff, P.J. and Melbourne, W.H. (1997), "Effects of free-stream turbulence on surface pressure fluctuations in a separation bubble", J. Fluid Mech., 337, 1-24. https://doi.org/10.1017/S0022112096004594.
  39. Solari, G. (1993), "Gust buffeting. I: Peak wind velocity and equivalent pressure", J. Struct. Eng., 119(2), 365-382. https://doi.org/10.1061/(ASCE)0733-9445(1993)119:2(365).
  40. Solari, G. and Kareem, A. (1998), "On the formulation of ASCE7-95 gust effect factor", J. Wind Eng. Ind. Aerod., 77, 673-684. https://doi.org/10.1016/S0167-6105(98)00182-2.
  41. Standohar-Alfano, C.D., Estes, H., Johnston, T., Morrison, M.J. and Brown-Giammanco, T.M. (2017), "Reducing losses from wind-related natural perils: Research at the IBHS Research Center", Front. Built Environ., 3, 9. https://doi.org/10.3389/fbuil.2017.00009.
  42. Stenabaugh, S.E., Iida, Y., Kopp, G.A. and Karava, P. (2015), "Wind loads on photovoltaic arrays mounted on sloped roofs of low-rise buildings, parallel to the roof surface", J. Wind Eng. Ind. Aerod., 139, 16-26. https://doi.org/10.1016/j.jweia.2015.01.007.
  43. Vickery, B.J. (1965), "On the flow behind a coarse grid and its use a model of atmospheric turbulence in studies related to wind loads on buildings", NPL Aero Report 1143.
  44. Wang, J. and Kopp, G.A. (2021a), "Comparisons of aerodynamic data with the Main Wind Force Resisting System provisions of ASCE 7-16 Part I: low-rise buildings", J. Struct. Eng., 147(3), 04020348. https://doi.org/10.1061/(ASCE)ST.1943-541X.0002925.
  45. Wang, J. and Kopp, G.A. (2021b), "Gust effect factors for windward walls of rigid buildings with various aspect ratios", J. Wind Eng. Ind. Aerod., 212, 104603. http://doi.org/10.1016/j.jweia.2021.104603.
  46. Wang, J. and Kopp, G.A. (2023), "Gust effect factors for regions of separated flow around rigid low, mid, and high-rise buildings", J. Wind Eng. Ind. Aerod., 232, 105254. http://dx.doi.org/10.1016/j.jweia.2022.105254.
  47. Wu, C.H. and Kopp, G.A. (2016) "Estimation of wind-induced pressures on a low-rise building using quasi-steady theory", Front. Built Environ., 2, 5. http://doi.org/10.3389/fbuil.2016.00005.
  48. Wu, C.H. and Kopp, G.A. (2018), "A quasi-steady model to account for the effects of upstream turbulence characteristics on pressure fluctuations on a low-rise building", J. Wind Eng. Ind. Aerod., 179, 338-357. http://doi.org/10.1016/j.jweia.2018.06.014.