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

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 lowspeed wind tunnels (23.029.7 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 lowblockage 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.