A parametric, experimental analysis of conical vortices on curved roofs of low-rise buildings

Different methods to reduce the high suction caused by conical vortices have been reported in the literature: vertical parapets, either solid or porous, placed at the roof edges being the most analysed configuration. Another method for alleviating the high suction peaks due to conical vortices is the use of some non-standard parapet configuration like cantilever parapets. In this paper the influence of roof curvature on the conical vortex pattern appearing on a curved roof (Fig. 1) when subject to oblique winds is experimentally analysed by testing the mean pressure distribution on the curved roofs of low-rise building models in a wind tunnel. Also, the efficiency of cantilever parapets to reduce mean suction loads on curved roofs is experimentally checked. Very high suction loads have been measured on curved roofs, the magnitude of these high suction loads being significantly decreased when cantilever parapets are used. Thus, the suitability of these parapets to reduce wind pressure loads on curved roofs is demonstrated.

[1]  A. Laneville,et al.  An Experimental Evaluation of Drag Coefficient for Rectangular Cylinders Exposed to Grid Turbulence , 1982 .

[2]  Theodore Stathopoulos,et al.  Roof corner wind loads and parapet configurations , 1988 .

[3]  David Surry,et al.  Wind loading of flat roofs with and without parapets , 1983 .

[4]  H. Kawai,et al.  Characteristics of fluctuating suction and conical vortices on a flat roof in oblique flow , 1996 .

[5]  Santiago Pindado,et al.  Wind tunnel study on the influence of different parapets on the roof pressure distribution of low-rise buildings , 2003 .

[6]  H. Tieleman,et al.  The distribution of pressure near roof corners of flat roof low buildings , 1995 .

[7]  M Kazakevitch.  The aerodynamics of a hangar membrane roof , 1998 .

[8]  Tatsuo Maeda,et al.  Aerodynamic Characteristics of Train/Vehicles under Cross Winds , 2001 .

[9]  C. J. Wood,et al.  Conical vortex movement and its effect on roof pressures , 1997 .

[10]  H. Kawai,et al.  Structure of conical vortices related with suction fluctuation on a flat roof in oblique smooth and turbulent flows , 1997 .

[11]  David Surry,et al.  Characteristics of mean and fluctuating pressure coefficients under corner (delta wing) vortices , 1994 .

[12]  Chris Letchford,et al.  On the influence of v and w component turbulence on roof pressures beneath conical vortices , 1997 .

[13]  R. P. Hoxey,et al.  The role of corner vortices in the design of structures , 1998 .

[14]  H. W. Tieleman,et al.  Model/full scale comparison of pressures on the roof of the TTU experimental building , 1996 .

[15]  R. J. Kind.  Worst suctions near edges of flat rooftops with parapets , 1988 .

[16]  Chris Letchford,et al.  Pressure factors for edge regions on low rise building roofs , 1995 .

[17]  Santiago Pindado,et al.  Wind Tunnel Analysis On The Influence OfCantilever Parapets On The Wind Loads OnCurved Roofs , 2004 .

[18]  Theodore Stathopoulos,et al.  Mean wind pressures on flat roof corners affected by parapets: field and wind tunnel studies , 1999 .

[19]  M. M. Zdravkovich,et al.  Aerodynamics of a covered pedestrian bridge of a trapezoidal section , 1997 .

[20]  D. Banks,et al.  Flow visualization of conical vortices on flat roofs with simultaneous surface pressure measurement , 2000 .

[21]  R. J. Kind,et al.  Worst suctions near edges of flat rooftops on low-rise buildings , 1986 .

[22]  Kishor C. Mehta,et al.  Full/model-scale comparison of surface pressures on the Texas Tech experimental building , 1996 .