Effect of High Blockage Ratios on Surface Pressures of an Inclined Flat Plate

Abstract

The walls of the wind tunnel test section affect severely the flow characteristics around bluff bodies. In this study, the blockage effect was experimentally investigated in two lowspeed wind tunnels (23.029.7 m/s). An inclined flat plate, representing blockage ratio of 2.11%17.64%, was installed on the wind tunnel floor. The mean surface pressures on the upper and lower surfaces in a smooth flow were measured. Compared with the data in the lowblockage tunnel, the effect of the magnitude of blockage ratio on the separated flow over the inclined flat plate was more sustainable. A procedure developed from the dynamic pressure increment around the model was employed. It is observed that the effect of blockage ratio on sectional lift and drag coefficients on the centerline of an inclined flat plate can be corrected through the application of a conventional blockage formula.

Wind Loads on a Solar Panel at High Tilt Angles

“…The blockage ratio is up to 6.3%. Note that a blockage correction is required for the mean surface pressure for a tilted panel if the blockage ratio is more than 10% [22].…”

Investigation of the Blockage Correction to Improve the Accuracy of Taylor’s Low-Speed Wind Tunnel

“…Ross and Altman [15] discovered that the identical vertical-axis wind turbine concept's wake characteristics and VAWT performance were evaluated at different physical sizes and in two distinct wind tunnels in an attempt to provide some direction on the scaling of the combined impacts on the blockage. Chung and Chen [16] devised a method for calculating the dynamic pressure increment around the model. It has been discovered that using a typical blockage formula, the effect of blockage ratio on the sectional lift and drag coefficients on the centreline of an inclined flat plate can be compensated.…”