A boundary layer wind tunnel for building aerodynamics

Abstract A wind tunnel of open-circuit configuration designed specifically for building aerodynamics is described and its performance is discussed. It has a working section 2 m wide × 1 m high × 8 m long with a maximum windspeed of 20 ms−1 under typical operating conditions. The overall length is 14 m. The tunnel has some special features to assist the simulation of the atmospheric boundary layer. At the upstream end of the working section is a region where various combinations of flow processing devices can be easily and quickly inserted. At the downstream end of the working section, a portion of the test area floor is removable and may be exchanged for a second floor unit. The test area is serviced by a 3-component traversing mechanism which allows the remote positioning of probes anywhere within the area. The flow conditions in the working section are satisfactory for a wide range of building aerodynamics studies. The characteristics of the fan allow a wide variation of power factor without a significant loss in maximum velocity. Full-depth atmospheric boundary layer simulations up to 1/500 scale and part-depth simulations up to 1/200 scale are practical in this tunnel.