Wind and Structures

Techno-Press (테크노프레스)
권호 표지
DOI QR코드

DOI QR Code

A compensation method for the scaling effects in the simulation of a downburst-generated wind-wave field

  • Haiwei Xu (College of Civil Engineering and Architecture, Zhejiang University) ;
  • Tong Zheng (College of Civil Engineering and Architecture, Zhejiang University) ;
  • Yong Chen (College of Civil Engineering and Architecture, Zhejiang University) ;
  • Wenjuan Lou (College of Civil Engineering and Architecture, Zhejiang University) ;
  • Guohui Shen (College of Civil Engineering and Architecture, Zhejiang University)
  • Received : 2023.06.29
  • Accepted : 2024.01.23
  • Published : 2024.04.25
⟨ Previous Next ⟩

Abstract

Before performing an experimental study on the downburst-generated wave, it is necessary to examine the scale effects and corresponding corrections or compensations. Analysis of similarity is conducted to conclude the non-dimensional force ratios that account for the dynamic similarity in the interaction of downburst with wave between the prototype and the scale model, along with the corresponding scale factors. The fractional volume of fluid (VOF) method in association with the impinging jet model is employed to explore the characteristics of the downburst-generated wave numerically, and the validity of the proposed scaling method is verified. The study shows that the location of the maximum radial wind velocity in a downburst-wave field is a little higher than that identified in a downburst over the land, which might be attributed to the presence of the wave which changes the roughness of the underlying surface of the downburst. The impinging airflow would generate a concavity in the free surface of the water around the stagnation point of the downburst, with a diameter of about two times the jet diameter (Djet). The maximum wave height appears at the location of 1.5Djet from the stagnation point. Reynolds number has an insignificant influence on the scale effects, in accordance with the numerical investigation of the 30 scale models with the Reynolds number varying from 3.85 × 104 to 7.30 × 109. The ratio of the inertial force of air to the gravitational force of water, which is denoted by G, is found to be the most significant factor that would affect the interaction of downburst with wave. For the correction or compensation of the scale effects, fitting curves for the measures of the downburst-wave field (e.g., wind profile, significant wave height), along with the corresponding equations, are presented as a function of the parameter G.

Keywords

Acknowledgement

The authors would like to acknowledge the financial support of National Natural Science Foundation of China (51878607, 51838012, and 51978614).

References

  1. Aboshosha, H., Elawady, A., El Ansary, A. and El Damatty, A. (2016), "Review on dynamic and quasi-static buffeting response of transmission lines under synoptic and non-synoptic winds", Eng. Struct., 112, 23-46. https://doi.org/10.1016/j.engstruct.2016.01.003. 
  2. Buckley, M.P. and Veron, F., (2016), "Structure of the airflow above surface waves", J. Phys. Oceanogr. 46, 1377-1397. https://doi.org/10.1175/JPO-D-15-0135.1. 
  3. Chen, Y., Hu, Z., Guo, Y., Wang, J., Dan, H., Liu, Q. and Pan, Y., (2019), "Ultimate bearing capacity of CHS X-joints stiffened with external ring stiffeners and gusset plates subjected to brace compression", Eng. Struct. 181, 76-88. https://doi.org/10.1016/j.engstruct.2018.12.005. 
  4. Chen, Y., Liu, G.-G. and Sun, B.-N. (2013), "Dynamic response of flat roofs subjected to non-stationary moving microbursts", Eng. Appl. Comput. Fluid Mech., 7, 519-532. https://doi.org/10.1080/19942060.2013.11015490. 
  5. Chun, H. and Suh, K.-D. (2018), "Estimation of significant wave period from wave spectrum", Ocean Eng., 163, 609-616. https://doi.org/10.1016/j.oceaneng.2018.06.043. 
  6. Donelan, M.A., Haus, B.K., Reul, N., Plant, W.J., Stiassnie, M., Graber, H.C., Brown, O.B. and Saltzman, E.S. (2004), "On the limiting aerodynamic roughness of the ocean in very strong winds", Geophys. Res. Lett., 31. https://doi.org/10.1029/2004GL019460. 
  7. Elawady, A. and El Damatty, A. (2016), "Longitudinal force on transmission towers due to non-symmetric downburst conductor loads", Eng. Struct., 127, 206-226. https://doi.org/10.1016/j.engstruct.2016.08.030. 
  8. Heller, V. (2011), "Scale effects in physical hydraulic engineering models", J. Hydraul. Res., 49, 293-306. https://doi.org/10.1080/00221686.2011.578914. 
  9. Heller, V. (2017), "Self-similarity and Reynolds number invariance in Froude modelling", J. Hydraul. Res., 55, 293-309. https://doi.org/10.1080/00221686.2016.1250832. 
  10. Hieu, P.D., Vinh, P.N., Van Toan, D. and Son, N.T. (2014), "Study of wave-wind interaction at a seawall using a numerical wave channel", Appl. Math. Model. 38, 5149-5159. https://doi.org/10.1016/j.apm.2014.04.038. 
  11. Hirt, C.W. and Nichols, B.D. (1981), "Volume of fluid (VOF) method for the dynamics of free boundaries", J. Comput. Phys., 39, 201-225. https://doi.org/10.1016/0021-9991(81)90145-5. 
  12. Holmes, J.D. and Oliver, S.E. (2000), "An empirical model of a downburst", Eng. Struct., 22, 1167-1172. https://doi.org/10.1016/S0141-0296(99)00058-9. 
  13. Kim, J. and Hangan, H. (2007), "Numerical simulations of impinging jets with application to downbursts", J. Wind Eng. Ind. Aerod., 95, 279-298. https://doi.org/10.1016/j.jweia.2006.07.002. 
  14. Kuethe, A.M. and Chow, C.-Y. (1997), Foundations of Aerodynamics: Bases of Aerodynamic Design. John Wiley & Sons. 
  15. Leng, X. and Chanson, H. (2017), "Unsteady turbulence, dynamic similarity and scale effects in bores and positive surges", Eur. J. Mech. - Bfluids, 61, 125-134. https://doi.org/10.1016/j.euromechflu.2016.09.017. 
  16. Li, C.Q. (2000), "A stochastic model of severe thunderstorms for transmission line design", Probabilistic Eng. Mech., 15, 359-364. https://doi.org/10.1016/S0266-8920(99)00037-5. 
  17. Lin, P. and Liu, P.L.-F. (2004), "Discussion of "Vertical variation of the flow across the surf zone", Coast. Eng., 50, 161-164. https://doi.org/10.1016/j.coastaleng.2003.09.002. 
  18. Longo, S. (2012), "Wind-generated water waves in a wind tunnel: Free surface statistics, wind friction and mean air flow properties", Coast. Eng., 61, 27-41. https://doi.org/10.1016/j.coastaleng.2011.11.008. 
  19. Longo, S., Chiapponi, L., Clavero, M., Makela, T. and Liang, D. (2012), "Study of the turbulence in the air-side and water-side boundary layers in experimental laboratory wind induced surface waves", Coast. Eng., 69, 67-81. https://doi.org/10.1016/j.coastaleng.2012.05.012. 
  20. Lou, W., Wang, J., Chen, Y., Lv, Z. and Lu, M., (2016), "Effect of motion path of downburst on wind-induced conductor swing in transmission line", Wind Struct., 23, 211-229. https://doi.org/10.12989/was.2016.23.3.211. 
  21. Macfarlane, G.J. (2009), "Correlation of prototype and modelscale wave wake characteristics of a Catamaran", Mar. Technol., SNAME News, 46, 1-15. https://doi.org/10.5957/mtsn.2009.46.1.1. 
  22. Sullivan, P.P. and McWilliams, J.C. (2010), "Dynamics of winds and currents coupled to surface waves", Annu. Rev. Fluid Mech., 42, 19-42. https://doi.org/10.1146/annurev-fluid-121108-145541. 
  23. Sun, Q., Wu, J., Wang, D., Xiang, Y., Liu, H. and Sun, X. (2020), "Analysis of the Quasi-Static buffeting responses of transmission lines to moving downburst", Comput. Model. Eng. Sci., 124, 287-302. https://doi.org/10.32604/cmes.2020.09118. 
  24. Tsai, Y.-S. and Lo, D.-C. (2020), "A ghost-cell immersed boundary method for wave-structure interaction using a two-phase flow model", Water, 12, 3346. https://doi.org/10.3390/w12123346. 
  25. Wang, F.Y., Xu, Y.L. and Qu, W.L. (2018), "Multi-scale failure analysis of transmission towers under downburst loading", Int. J. Struct. Stab. Dyn., 18, 1850029. https://doi.org/10.1142/S0219455418500293. 
  26. Wang, M., Zhang, C. and Li, R. (2016), "Uniformity evaluation and optimization of fluid flow characteristics in a seven-strand tundish", Int. J. Miner. Metall. Mater., 23, 137-145. https://doi.org/10.1007/s12613-016-1220-5. 
  27. Wang, Z., Yang, J. and Stern, F. (2012), "A new volume-of-fluid method with a constructed distance function on general structured grids", J. Comput. Phys., 231, 3703-3722. https://doi.org/10.1016/j.jcp.2012.01.022. 
  28. Wei, G. and Kirby, J.T. (1995), "Time-dependent numerical code for extended boussinesq equations", J. Waterw. Port Coast. Ocean Eng., 121, 251-261. https://doi.org/10.1061/(ASCE)0733-950X(1995)121:5(251). 
  29. Wood, G.S., Kwok, K.C.S., Motteram, N.A. and Fletcher, D.F. (2001), "Physical and numerical modelling of thunderstorm downbursts", J. Wind Eng. Ind. Aerod., 89, 535-552. https://doi.org/10.1016/S0167-6105(00)00090-8. 
  30. Xu, F., Chen, J., Guo, Y. and Ye, Y. (2019), "Innovative design of the world's tallest electrical transmission towers", Proc. Inst. Civ. Eng. - Civ. Eng., 172, 9-16. https://doi.org/10.1680/jcien.18.00021. 
  31. Yang, S.C. and Hong, H.P., (2016), "Nonlinear inelastic responses of transmission tower-line system under downburst wind", Eng. Struct., 123, 490-500. https://doi.org/10.1016/j.engstruct.2016.05.047. 
  32. Young, I.R. (1999), Wind Generated Ocean Waves. Elsevier. 
  33. Zhang, S., Solari, G., De Gaetano, P., Burlando, M. and Repetto, M.P. (2018), "A refined analysis of thunderstorm outflow characteristics relevant to the wind loading of structures", Probabilistic Eng. Mech., 54, 9-24. https://doi.org/10.1016/j.probengmech.2017.06.003. 
  34. Zheng, T. (2022), "Study on the wind-generated wave and windwave field under the Downburst", Master Thesis, Zhejiang University, Hangzhou. (in Chinese)