DOI QR코드

DOI QR Code

Field measurements of wind characteristics over hilly terrain within surface layer

  • He, Y.C. (Deparment of Architecture and Civil Engineering, City University of Hong Kong) ;
  • Chan, P.W. (Hong Kong Observatory) ;
  • Li, Q.S. (Deparment of Architecture and Civil Engineering, City University of Hong Kong)
  • Received : 2014.01.03
  • Accepted : 2014.08.31
  • Published : 2014.11.25

Abstract

This paper investigates the topographic effects on wind characteristics over hilly terrain, based on wind data recorded at a number of meteorological stations in or near complex terrain. The multiply data sources allow a more detailed investigation of the flow field than is normally possible. Vertical profiles of mean and turbulent wind components from a Sodar profiler were presented and then modeled as functions of height and wind speed. The correlations between longitudinal and vertical wind components were discussed. The phenomena of flow separation and generation of vortices were observed. The distance-dependence of the topographic effects on gust factors was revealed subsequently. Furthermore, the canyon effect was identified and discussed based on the observations of wind at a saddle point between two mountain peaks. This study aims to further understanding of the characteristics of surface wind over rugged terrain. The presented results are expected to be useful for structural design, prevention of pollutant dispersion, and validation of CFD (computational fluid dynamics) models or techniques over complex terrains.

Keywords

wind characteristics;hilly terrain;profile;flow separation;canyon effect;topographic effect

Acknowledgement

Supported by : National Natural Science Foundation

References

  1. Apsley, D.D. and Castro, I.P. (1997), "Flow and dispersion over hills: comparison between numerical predictions and experimental data", J. Wind Eng. Ind. Aerod., 67-68, 375-386. https://doi.org/10.1016/S0167-6105(97)00087-1
  2. Architectural Institute of Japan (2004), AIJ Recommendation for Loads on Building, Japan.
  3. ASCE 7 (2005), Wind loads, American Society of Civil Engineers ASCE7-05 Standard.
  4. Baker, C.J. (1984), "Determination of topographical exposure factors in complicated hilly terrain", J. Wind Eng.Ind. Aerod., 17(2), 239-249. https://doi.org/10.1016/0167-6105(84)90058-8
  5. Cao, S.Y. and Tamura, T. (2006), "Experimental study on roughness effects on turbulent boundary layer flow over a two-dimensional steep hill", J. Wind Eng. Ind. Aerod., 94(1), 1-19. https://doi.org/10.1016/j.jweia.2005.10.001
  6. Baker, C.J., Wood, C.J. and Gawthorpe R.G. (1985), "Strong wind in complicated hilly terrain-field measurements and wind-tunnel study", J. Wind Eng.Ind. Aerod., 18(1), 1-26. https://doi.org/10.1016/0167-6105(85)90072-8
  7. Beljaars, A.C.M., Walmsley, J.L. and Taylor, P.A. (1987), "A mixed spectral finite-difference model for neutrally stratified boundary-layer flow over roughness changes and topography", Bound.- Lay. Meteor., 38(3), 273-303. https://doi.org/10.1007/BF00122448
  8. Bowen, A.J. and Clucas, H. (1992), "The measurement and interpretation of peak-gust wind speeds over an isolated hill", J. Wind Eng.Ind. Aerod., 41-44, 381-392.
  9. Cao, S.Y., Wang, T., Ge, Y.J. and Tamura, Y. (2012), "Numerical study on turbulent boundary layers over two-dimensional hills-effects of surface roughness and slope", J. Wind Eng. Ind. Aerod., 104-106, 342-349. https://doi.org/10.1016/j.jweia.2012.02.022
  10. Chan, P.W. (2008), "Measurement of turbulence intensity profile by a mini-sodar", Meteorol. Appl., 15(2), 249-258. https://doi.org/10.1002/met.66
  11. Chan, P.W. (2014), "Observation and numerical simulation of vortex/wave shedding for terrain-distributed airflow at the Hong Kong International Airport during Typhoon Nesat in 2011", Meteorol. Appl., 21, 512-520. https://doi.org/10.1002/met.1310
  12. Cochran, L. and Derickson, R. (2011), "A physical modeler's view of computational wind engineering", J. Wind Eng. Ind. Aerod., 99(4), 139-153. https://doi.org/10.1016/j.jweia.2011.01.015
  13. Coppin, P.A., Bradley, E.F. and Finnigan, J.J. (1994), "Measurements of flow over an elongated ridge and its thermal stability dependence: the mean field", Bound.-Lay. Meteor., 69(1-2), 173-199. https://doi.org/10.1007/BF00713302
  14. Derickson, R.G. and Peterka, J.A. (2004), "Development of a powerful hybrid tool for evaluating wind power in complex terrain: atmospheric numerical models and wind tunnels", Proceedings of the 23rdASME Wind Energy Symposium, 15, Reno, Nevada, USA.
  15. ESDU (1985), Characteristics of atmospheric turbulence near the ground. Part 2: single point data for strong winds (neutral atmosphere). Item No. 85020, ESDU International, London, UK.
  16. Griffiths, A.D. and Middleton, J.H. (2010), "Simulations of separated flow over two dimensional hills", J. Wind Eng.Ind. Aerod., 98(3), 155-160. https://doi.org/10.1016/j.jweia.2009.10.011
  17. ESDU (1983), Strong wind in the atmospheric boundary layer, Part 2: Discrete gust speeds. Item No. 83045, ESDU International, London, UK.
  18. Garratt, J.R. (1992), The Atmospheric Boundary Layer, Cambridge atmospheric and space science series, Cambridge University Press, New York, USA.
  19. GB50009-2012 (2012), China Academy of Building Research, National load codes for the design of building structures, China Architectural & Building Press, Beijing, China.
  20. He, Y.C., Chan, W.P. and Li, Q.S. (2013), "Wind characteristics under different terrain conditions", J. Wind Eng. Ind. Aerod., 120, 51-69. https://doi.org/10.1016/j.jweia.2013.06.016
  21. Hunt, J.C.R., Abell, C.J., Peterka, J.A. and Woo, H. (1978), "Kinematical studies of the flows around free or surface-mounted obstacles; applying topology to flow visualization", J. Fluid Mech., 86(1), 179-200. https://doi.org/10.1017/S0022112078001068
  22. Hunt, J.C.R., Leibovich, S. and Richards, K.J. (1988), "Turbulent shear flows over low hills", Q. J. Roy. Meteor. Soc., 114(484), 1435-1470. https://doi.org/10.1002/qj.49711448405
  23. Hunt, J.C.R. and Richards, K.J. (1984), "Stratified airflow over one or two hills", Bound.- Lay. Meteor., 30, 223-259. https://doi.org/10.1007/BF00121956
  24. Jackson, P.S. and Hunt, J.C.R. (1975), "Turbulent wind flow over a low hill", Q. J. Roy. Meteor. Soc., 101(430), 929-955. https://doi.org/10.1002/qj.49710143015
  25. Keith, W.A. and Dale, E.H. (2004), "Observations of boundary-layer wind-tunnel flow over isolated ridges of varying steepness and roughness", Bound.- Lay. Meteor., 112(3), 525-556. https://doi.org/10.1023/B:BOUN.0000030663.13477.51
  26. Kustas, W.P. and Brutsaert, W. (1986), "Wind profile constants in a neutral atmospheric boundary layer over complex terrain", Bound.-Lay. Meteor., 34(1-2), 35-54. https://doi.org/10.1007/BF00120907
  27. Lemelin, D.R., Surry, D. and Davenport, A.G. (1988), "Simple approximations for wind speed-up over hills", J. Wind Eng.Ind. Aerod., 28(1-3), 117-127. https://doi.org/10.1016/0167-6105(88)90108-0
  28. Mengelkamp, H.T. (1999), "Wind climate simulation over complex terrain and wind turbine energy output estimation", Theor. Appl. Climatol., 63(3-4), 129-139. https://doi.org/10.1007/s007040050098
  29. Mason, P.J. and Sykes, R.I. (1979), "Flow over an isolated hill of moderate slope", Q. J. Roy. Meteor. Soc., 105(444), 383-395. https://doi.org/10.1002/qj.49710544405
  30. Mason, P. J. and King, J. C. (1985), "Measurements and predictions of flow and turbulence over an isolated hill of moderate slope", Quart. J. Roy. Meteor. Soc., 111(468), 617-640. https://doi.org/10.1002/qj.49711146818
  31. Masters, F.J., Vickery, P.J., Bacon, P. and Rappaport, E.N. (2010), "Toward objective, standardized intensity estimates from surface wind speed observations", B. Am. Meteorol. Soc., 91(12), 1665-1681. https://doi.org/10.1175/2010BAMS2942.1
  32. Mickle, R.E., Cook, N.J., Hoff, A.M., Jensen, N.O., Salmon, J.R., Taylor, P.A., Tetzlaff, G. and Tunissen, H.W. (1988), "The Askervein Hill Project: vertical profiles of wind and turbulence", Bound.- Lay. Meteor., 43(1-2), 143-169. https://doi.org/10.1007/BF00153977
  33. Ngo, T. and Letchford, C. (2008), "A comparison of topographic effects on gust wind speed", J. Wind Eng. Ind. Aerod., 96(12), 2273-2293. https://doi.org/10.1016/j.jweia.2008.01.002
  34. Powell, M.D., Vickery, P.J. and Reinhold, T.A. (2003), "Reduced drag coefficient for high wind speeds in tropical cyclones", Nature, 422, 279-283. https://doi.org/10.1038/nature01481
  35. Salmon, J.R., Bowen, A.J., Hoff, A.M., Johnson, R., Mickle, R.E., Taylor, P.A., Tetzlaff, G. and Walmsley, J.L. (1988), "The Askervein Hill Project: mean wind variations at fixed heights above ground", Bound.- Lay. Meteor., 43(3), 247-271. https://doi.org/10.1007/BF00128406
  36. Stearns, C.R. (1970), "Determining surface roughness and displacement height", Bound.- Lay. Meteor., 1(1), 102-111. https://doi.org/10.1007/BF00193908
  37. Tamura, T., Cao, S.Y. and Okuno, A. (2007a), "LES study of turbulent boundary layer over a smooth and a rough 2D hill model", Flow Turbul. Combust., 79(4), 405-432. https://doi.org/10.1007/s10494-007-9106-2
  38. Tamura, T., Okuno, A. and Sugio, Y. (2007b), "LES analysis of turbulent boundary layer over 3D steep hill covered with vegetation", J. Wind Eng.Ind. Aerod., 95(9-11), 1463-1475. https://doi.org/10.1016/j.jweia.2007.02.014
  39. Tamura, Y., Iwatani, Y., Hibi, K., Suda, K., Nakamura, O., Maruyama, T. and Ishibashi, R. (2007), "Profiles of mean wind speeds and vertical turbulence intensities measured at seashore and two inland sites using Doppler SODAR", J. Wind Eng.Ind. Aerod., 95(6), 411-427. https://doi.org/10.1016/j.jweia.2006.08.005
  40. Takahashi, T., Ohtsu, T., Yassin, M.F. and Kato, S. (2002), "Turbulence characteristics of wind over a hill with a rough surface", J. Wind Eng.Ind. Aerod., 90(12-15), 1697-1706. https://doi.org/10.1016/S0167-6105(02)00280-5
  41. Taylor, P.A., Mason, P.J. and Bradley, E.F. (1987), "Boundary-layer flow over low hills", Bound.- Lay. Meteor., 39(1-2), 107-132. https://doi.org/10.1007/BF00121870
  42. Taylor, P.A. and Teunissen, H.W. (1987), "The Askervein Hill Project: overview and background data", Bound.- Lay. Meteor., 39(1-2), 15-39. https://doi.org/10.1007/BF00121863
  43. Taylor, P.A. (1998), "Turbulent boundary-layer flow over low and moderate slope hills", J. Wind Eng. Ind. Aerod., 74-76, 25-47. https://doi.org/10.1016/S0167-6105(98)00005-1
  44. Walmsley, J.L., Salmon, J.R. and Taylor, P.A. (1982), "On the application of a model of boundary-layer flow over low hills to real terrain", Bound.- Lay. Meteor., 23(1), 17-46. https://doi.org/10.1007/BF00116110
  45. Walmsley, L. and Taylor P.A. (1996), "Boundary-layer flow over topography: impacts of the Askervein study", Bound.-Lay. Meteor., 78, 291-320. https://doi.org/10.1007/BF00120939
  46. Wiggs, G.F.S., Livingstone, I, Thomas, D.S.G. and Bullard, J.E. (1996), "Airflow and roughness characteristics over partially vegetated linear dunes in the southwest Kalahari Desert", Earth Surf. Proc. Land., 21, 19-34. https://doi.org/10.1002/(SICI)1096-9837(199601)21:1<19::AID-ESP508>3.0.CO;2-P
  47. Wood, N. (1995), "The onset of separation in neutral, turbulent flow over hills", Bound.- Lay. Meteor., 76(1-2), 137-164. https://doi.org/10.1007/BF00710894
  48. Wood, N. (2000), "Wind flow over complex terrain: a historical perspective and the prospect for large-eddy modeling", Bound.- Lay. Meteor., 96(1-2), 11-32. https://doi.org/10.1023/A:1002017732694
  49. Xu, D., Ayotte, K.W. and Taylor, P.A. (1994), "Development of the NLMSFD model of turbulent boundary-layer flow over topography", Bound.- Lay. Meteor., 70, 341-367. https://doi.org/10.1007/BF00713775

Cited by

  1. Observational study on thermodynamic and kinematic structures of Typhoon Vicente (2012) at landfall vol.172, 2018, https://doi.org/10.1016/j.jweia.2017.11.008
  2. Estimation of roughness length at Hong Kong International Airport via different micrometeorological methods vol.171, 2017, https://doi.org/10.1016/j.jweia.2017.09.019
  3. Standardization of Offshore Surface Wind Speeds vol.55, pp.5, 2016, https://doi.org/10.1175/JAMC-D-15-0299.1
  4. Vertical wind profiles for typhoon, monsoon and thunderstorm winds vol.168, 2017, https://doi.org/10.1016/j.jweia.2017.06.004