DOI QR코드

DOI QR Code

3-D characteristics of conical vortex around large-span flat roof by PIV technique

  • Sun, Huyue (Key Laboratory of Concrete and Pre-stressed Concrete Structures of China Ministry of Education, Southeast University) ;
  • Ye, Jihong (Key Laboratory of Concrete and Pre-stressed Concrete Structures of China Ministry of Education, Southeast University)
  • 투고 : 2015.05.15
  • 심사 : 2016.04.19
  • 발행 : 2016.06.25

초록

Conical vortices generated at the corner regions of large-span flat roofs have been investigated by using the Particle Image Velocimetry (PIV) technique. Mean and instantaneous vector fields for velocity, vorticity, and streamlines were measured at three visual planes and for two different flow angles of $15^{\circ}$. The results indicated that conical vortices occur when the wind is not perpendicular to the front edge. The location of the leading edge corresponding to the negative peak vorticity and maximum turbulent kinetic energy was found at the center of the conical vortex. The wind pressure reaches the maximum near the leading edge roof corner, and a triangle of severe suctions zone appears downstream. The mean pressure in uniform flow is greater than that under turbulent flow condition, while a significant increase in the fluctuating wind pressure occurs in turbulent streams. From its emergence to stability, the shape of the vortex cross-section is nearly elliptical, with increasing area. The angle that forms between the vortex axis and the leading edge is much smaller in turbulent streams. The detailed flow structures and characteristics obtained through FLUENT simulation are in agreement with the experimental results. The three dimensional (3-D) structure of the conical vortices is clearly observed from the comprehensive arrangement of several visual planes, and the inner link was established between the vortex evolution process, vortex core position and pressure distribution.

키워드

참고문헌

  1. Arie, M. and Rouse, H. (1956), "Experiments on two-dimensional flow over a normal wall", J. Fluid Mech., 1(2), 129-141. https://doi.org/10.1017/S0022112056000093
  2. Banks, D., Meroney, R.N., Sarkar, P.P., Zhao, Z. and Wu, F. (2000), "Flow visualization of conical vortices on flat roofs with simultaneous surface pressure measurement", J. Wind Eng. Ind. Aerod., 84, 65-85. https://doi.org/10.1016/S0167-6105(99)00044-6
  3. Banks, D. and Meroney, R.N. (2001), "A model of roof top surface pressures produced by conical vortices: Evaluation and implications", Wind Struct., 4(2), 1-20. https://doi.org/10.12989/was.2001.4.1.001
  4. Gu, Z.F., Yang, L.T. and Chen, Q.S. (2008), "Wind loading on plane roof of a large hangar", Acta Scientiarum Naturalium Universitatis Pekinensis, 44(4), 501-506.
  5. Kawai, H. and Nishimura, G. (1996), "Characteristics of fluctuating suction and conical vortices in a flat roof in oblique flow", J. Wind Eng. Ind. Aerod., 60, 211-225. https://doi.org/10.1016/0167-6105(96)00035-9
  6. Kim, K.C., Ji, H.S. and Seong, S.H. (2001), "PIV measurement of roof corner vortices", Wind Struct., 4(5), 441-454. https://doi.org/10.12989/was.2001.4.5.441
  7. Li, J.G. (2007), "Flow-trace and Pressure Measuring Experiments of Boundary Layer Wind Tunnel and Standard Building Model", Shanghai: Civil Engineering, Tongji University.
  8. Tutar, M. and Oguz, G. (2002), "Large eddy simulation of wind flow around parallel buildings with varying configuration", Fluid Dynam. Res., 9, 289-315.
  9. Wu, F., Sarkar, P.P., Mehta, K.C. and Zhao, Z. (2001), "Influence of incident wind turbulence on pressure fluctuations near flat-roof corners", J. Wind Eng. Ind. Aerod., 89(5), 403-420. https://doi.org/10.1016/S0167-6105(00)00072-6
  10. Ye, J.H. and Dong, X. (2014), "Improvement and validation of a flow model for conical vortices", Wind Struct., 19(2), 113-144. https://doi.org/10.12989/was.2014.19.2.113
  11. Zhao, Z. (1997), "Wind flow characteristics and their effects in low-rise buildings", Lubbock, Texas: Civil Engineering, Texas Tech University.

피인용 문헌

  1. Investigation of crossflow features of a slender delta wing vol.31, pp.3, 2016, https://doi.org/10.12989/was.2020.31.3.229