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The Interplay Between Background Atmospheric Boundary Layer Winds and Downburst Outflows. A First Physical Experiment

  • D. RomanicEmail author
  • H. Hangan
Conference paper
Part of the Lecture Notes in Civil Engineering book series (LNCE, volume 27)

Abstract

This paper studies the interaction between downburst outflows and the background atmospheric boundary layer (ABL) winds close to the surface. Downburst is a buoyancy-driven downdraft of cold air that emerges from cumuliform clouds and results in a vigorous starburst outflows upon reaching the surface. Currently, there are neither satisfactory analytical models nor experimental results on the highly complex interaction between these two wind systems. One of the advanced modes of the WindEEE Dome operation, at Western University in Canada, enables the simultaneous generation of downbursts and ABL winds. In accordance with the WindEEE Dome capabilities, an experiment is designed to address this long-standing question on the relationship between ABL winds and downbursts. This paper shows the interaction between downburst and ABL winds for seven azimuthal positions in respect to the incoming ABL wind direction and six heights. The results show that the traditional approach of adding ABL winds to downburst outflow as either vector or algebraic sum is inaccurate for all heights and azimuth angles. A new empirical relationship between downbursts with and without ABL winds is presented herein.

Keywords

Downburst Thunderstorm Wind simulator Flow interaction WindEEE Dome 

Notes

Acknowledgements

The authors thank Julien LoTufo for his technical help in conducting the experiments in the WindEEE Dome. Constructive comments from two anonymous reviewers are highly appreciated.

References

  1. Abd-Elaal E-S, Mills JE, Ma X (2014) Empirical models for predicting unsteady-state downburst wind speeds. J Wind Eng Ind Aerodyn 129:49–63CrossRefGoogle Scholar
  2. Burlando M, Romanic D, Solari G, Hangan H, Zhang S (2017) Field data analysis and weather scenario of a downburst event in Livorno, Italy, on 1 October 2012. Mon Weather Rev 145:3507–3527CrossRefGoogle Scholar
  3. Elawady A, Aboshosha H, El Damatty A, Bitsuamlak G, Hangan H, Elatar A (2017) Aero-elastic testing of multi-spanned transmission line subjected to downbursts. J Wind Eng Ind Aerodyn 169:194–216CrossRefGoogle Scholar
  4. Chay MT, Albermani F, Wilson R (2006) Numerical and analytical simulation of downburst wind loads. Eng Struct 28:240–254CrossRefGoogle Scholar
  5. Fujita TT (1981) Tornadoes and downbursts in the context of generalized planetary scales. J Atmos Sci 38:1511–1534CrossRefGoogle Scholar
  6. Fujita TT (1985) The downburst: microburst and macroburst. Satellite and Mesometeorology Research Project, Department of the Geophysical Sciences, University of Chicago, Chicago, Illinois, United StatesGoogle Scholar
  7. Gutmark E, Wolfshtein M, Wygnanski I (1978) The plane turbulent impinging jet. J Fluid Mech 88:737–758CrossRefGoogle Scholar
  8. Hall JW, Ewing D (2005) The development of the large-scale structures in round impinging jets exiting long pipes at two Reynolds numbers. Exp Fluids 38:50–58CrossRefGoogle Scholar
  9. Hangan H (2010) Current and future directions for wind research at western: a new quantum leap in wind research through the wind engineering, energy and environment (WindEEE) Dome. Wind Eng JAWE 35:277–281CrossRefGoogle Scholar
  10. Hangan H, Refan M, Jubayer CM, Romanic D, Parvu D, LoTufo J, Costache A (2017) Novel techniques in wind engineering. J Wind Eng Ind Aerodyn 171:13–33CrossRefGoogle Scholar
  11. Hjelmfelt MR (1988) Structure and life cycle of microburst outflows observed in Colorado. J Appl Meteorol 27:900–927CrossRefGoogle Scholar
  12. Ho C-M, Nosseir NS (1981) Dynamics of an impinging jet. Part 1. The feedback phenomenon. J Fluid Mech 105:119–142CrossRefGoogle Scholar
  13. Holmes JD, Oliver SE (2000) An empirical model of a downburst. Eng Struct 22:1167–1172CrossRefGoogle Scholar
  14. Holmes JD, Hangan HM, Schroeder JL, Letchford CW, Orwig KD (2008) A forensic study of the Lubbock-Reese downdraft of 2002. Wind Struct 11:137–152CrossRefGoogle Scholar
  15. Jubayer CM, Hangan H (2018) A hybrid approach for evaluating wind flow over a complex terrain. J Wind Eng Ind Aerodyn 175:65–76CrossRefGoogle Scholar
  16. Jubayer CM, Romanić D, Hangan H (2017) Effect of a large scale impinging jet on a standard tall building. In: 7th European and African conference on wind engineering (EACWE 2017), Liège, Belgium, 3–6 July 2017Google Scholar
  17. Jubayer CM, Elatar A, Hangan H (2016) Pressure distributions on a low-rise building in a laboratory simulated downburst. In: Bluff body aerodynamics and applications, Boston, Massachusetts, United States, 7–11 June 2016Google Scholar
  18. Kim J, Hangan H (2007) Numerical simulations of impinging jets with application to downbursts. J Wind Eng Ind Aerodyn 95:279–298CrossRefGoogle Scholar
  19. Lompar M, Ćurić M, Romanic D (2018) Implementation of a gust front head collapse scheme in the WRF numerical model. Atmos Res 203:231–245CrossRefGoogle Scholar
  20. Refan M, Hangan H (2018) Near surface experimental exploration of tornado vortices. J Wind Eng Ind Aerodyn 175:120–135CrossRefGoogle Scholar
  21. Romanic D, Parvu D, Hangan H (2017) Influence of background winds and storm motion on downburst outflow. In: 7th European and African conference on wind engineering (EACWE 2017), Liège, Belgium, 3–6 July 2017Google Scholar
  22. Solari G, Repetto MP, Burlando M, De Gaetano P, Pizzo M, Tizzi M, Parodi M (2012) The wind forecast for safety management of port areas. J Wind Eng Ind Aerodyn 104–106:266–277CrossRefGoogle Scholar
  23. Solari G, De Gaetano P, Repetto MP (2015) Thunderstorm response spectrum: fundamentals and case study. J Wind Eng Ind Aerodyn 143:62–77CrossRefGoogle Scholar

Copyright information

© Springer Nature Switzerland AG 2019

Authors and Affiliations

  1. 1.Wind Engineering, Energy and Environment (WindEEE) Research InstituteWestern UniversityLondonCanada

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