Pressures on surface-mounted prisms: The effects of incident turbulence

Abstract This paper discusses the effect of small-scale turbulence on the pressures observed on surface-mounted prisms placed in a variety of turbulent boundary layers. The effects of turbulence intensity and prism geometry are discussed in detail for oblique angles of attack with emphasis on observations on the top surface near the upstream corner and along its leading edges. In order to achieve a better simulation of the lateral turbulence intensity and the small-scale turbulence, small spires are placed directly upstream of the model location. Model/full scale comparison of the mean and fluctuating pressure coefficients are made to evaluate the effect of the spires on these coefficients in comparison with the conventional spire-roughness simulation method. Two specific situations are discussed with emphasis on the very low suction pressures usually encountered near the leading prism edges and under the corner vortices.

[1]  B. J. Vickery.  Fluctuating lift and drag on a long cylinder of square cross-section in a smooth and in a turbulent stream , 1966, Journal of Fluid Mechanics.

[2]  H. W. Tieleman,et al.  Problems associated with flow modelling procedures for low-rise structures , 1992 .

[3]  R. Akins.  Effects of turbulence on mean force and moment coefficients , 1992 .

[4]  P. W. Bearman,et al.  An Investigation of the Flow around Rectangular Cylinders , 1972 .

[5]  Jack E. Cermak,et al.  Physical modelling of the atmospheric surface layer , 1992 .

[6]  T. Morel,et al.  Effect of free stream turbulence on the flow around bluff bodies , 1983 .

[7]  E. C. Polhamus.  Vortex lift research: Early contributions and some current challenges , 1986 .

[8]  W. H. Melbourne,et al.  THE GENERATION OF PEAK PRESSURES IN SEPARATED/REATTACHING FLOWS , 1989 .

[9]  Multi-sensor investigation of delta wing high-alpha aerodynamics , 1991 .

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

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

[12]  W. H. Melbourne.  TURBULENCE EFFECTS ON MAXIMUM SURFACE PRESSURES - A MECHANISM AND POSSIBILITY OF REDUCTION , 1980 .

[13]  Kishor C. Mehta,et al.  Texas Tech field experiments for wind loads part 1: building and pressure measuring system , 1992 .

[14]  A Bailey,et al.  Wind pressures on buildings , 1933 .

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