The characteristics of the ABRI wind tunnel

In 2001, the ABRI (Architecture and Building Research Institute, Ministry of the Interior, Taiwan) initiated a project to establish an environmental wind tunnel in the Kui-Ren campus of National Cheng Kung University. This project was completed in 2004. The wind tunnel is of a closed-return type, featuring two test sections in series. The primary test section is 3 m by 2.6 m in cross section and 36.5 m in length; the secondary test section is 6 m by 2.6 m in cross section and 21 m in length. The wind tunnel uses a 500 KW axial fan. Immediately after the completion of the wind tunnel, the wind tunnel was calibrated. The results of the calibration indicate that the maximum speed at the inlet of the primary test section is 36 m/s and that the turbulence intensity and non-uniformity of the flow measured at the inlet of the main test section are less than 0.3% and 0.4%, respectively. At a flow of speed more than 30 m/s, the energy ratio calculated from the fan test data, is about 0.94, which almost coincides with that predicted by the design data. The flow quality of the wind tunnel was further examined using an experiment withtwo circular cylinders at Reynolds numbers in the critical regime. The base pressure coefficients measured were found to be in good agreement with those reported in the literature. The oil-film flow visualization performed in this experiment further provides information regarding the flow patterns corresponding to different flow states in the critical regime.