Abstract:Experiments were performed on 3∶1 rectangular prisms with various rounded corners (R/D=0, 5%, 10%, 15%) in low turbulence uniform flow to measure the surface pressures of four models for the testing Reynolds number ranging from 1.1×105 to 6.8×105. The aerodynamic forces were obtained by integrating the wind pressures on the model surface. Reynolds number effects on the aerodynamic force coefficients and their power spectrums are presented. The results show that drag coefficients of rectangular prisms with R/D=0 and 5% increase with the increasing Reynolds numbers, whereas sudden decreases of the drag coefficients root mean square(RMS) drag coefficients and RMS lift coefficients are observed for the rectangular prisms with R/D=10% and 15%. The power spectrums of drag and lift coefficients for rectangular prisms with R/D=0 and 5% change slightly with the increasing Reynolds numbers, whereas significant influences of the Reynolds number on the power spectrums of areodynamic force coefficients are found for the models with R/D=10% and 15%. Besides, Strouhal numbers of the 3∶1 rectangular prisms obviously increase with the increasing rounded corner ratio.
