FLOW PATTERNS AND PRESSURE FIELD AROUND A FULL-SCALE BUILDING

This paper describes measurements of the flow patterns and pressure fi eld around a low-rise portal framed building (24 m long x 13 m span x 4 m eaves height, 10-degrees roof pitch) on which extensive full-scale wind load measurements have been made. Flow patterns have been observ ed using smoke, generated from a smoke canister, nylon tufts attached to the surface of the building, and on one occasion the deposition of snow on and around the building. These techniques provide some quantit ative information about the flow pattern but are primarily qualitative , aiding an understanding of the three-dimensional flow field for comp arison with wind-tunnel studies and computational fluid dynamics predi ctions. A technique, using static pressure probes, is described which provides more quantitative information on the pressure field around th e building for a wind direction transverse to the line of the ridge. M easurements were made on the major axes of the building, extending to 50 m upstream, 10 m downstream, and 20 m to one side. Over 220 hours o f recordings were made when the mean wind speed at building ridge heig ht was greater than 8 m/s. Results of these pressure field measurement s are presented and compared with predictions from computational fluid dynamics using a k-epsilon model. These results have implications for the siting of instrumentation in boundary layer wind tunnels where a major problem has been the location of the reference static pressure s ensor. The static pressure field measurements give an indication of su itable locations and possible levels of error in past work.