REYNOLDS NUMBER EFFECTS ON FREQUENCY DOMAIN CHARACTERISTICS OF WIND PRESSURES ON 2D RECTANGULAR PRISMS

Pressure measurement tests of 2D rectangular prisms with side ratios of 2, 2.5, 3, 3.5 and 4 were performed, which were conducted in low-turbulence uniform flow with the Reynolds number ranging from 1.1×10⁵ to 6.8×10⁵. Power spectra of pressure coefficients for three typical measuring points on the surface of each model were analyzed, and pressure correlations on the side surfaces of each model were studied. The results show that power spectra of pressure coefficients of three typical measuring points are obviously influenced by the flow reattachment on the side surface of the model, and power spectra of pressure coefficients of three typical measuring points on the surface of the 4:1 rectangular prism are Reynolds number dependent. Good correlation of wind pressures on the side surface of the 2:1 rectangular prism is observed. For rectangular prisms with side ratios of 2.5, 3 and 3.5, good correlations of the pressures near the leading edge and the trailing edge are observed, whereas the wind pressures near the midpoint of the side surface have poor correlations with the wind pressures near the leading and trailing edges. For the 4:1 rectangular prism, significant changes in the pressure correlation at the Reynolds number of 6.8×10⁵ are observed.