Briefly discusses wind-pressure on buildings. Derives equations for air-flow in a building without internal walls caused by wind pressure from perpendicular and oblique wind. Gives simplified method for calculating air flows inside a building with internal walls. Gives tables showing results of calculation of air flows for a building with two and three rooms. Discusses more complicated building types and gives results of calculation. Outlines determination of ventilation heat loss, air leakage of windows and doors.
Detailed sets of time-averaged surface pressure coefficients were recorded over the walls and roof of a rectangular building model, set in a simulated high density urban area. The 1/400 scale model represented a generalized smooth surfaced building of 100x150 ft plan form, whose height varied from 300 ft to 200,100 and 50ft. Surrounding roughness elements equalled the heightof the 50ft, building model. Tests were carried out at twelve wind angles using a power low velocity profile with an exponent of 0.43.
Presents results of measurements of fluctuating wind pressures on prisms of square and rectangular section mounted on the rooftop of a 4-storied building. Describes models and experimental methods. Finds pressure fluctuations of thewindward side are subject to the influence of wind turbulence. Negative pressure on leeward side is relatively stable exceptwhere strong vortices are being shed Very high negative pressures were observed intermittently along the edges of a top board.
Developes procedure for calculating air infiltration rates due to wind pressures on the exterior walls of buildings, assuming no chimney and mechanical ventilation effects. Assumes resistance to internal air flow is small. Using results of wind tunnel test, presents calculations showing the significant effects a single neighbouring building can have on the infiltration rates. Relative building heights, distance between buildings and wind direction are varied, and both uniform and shear flows are considered.
Discusses use of long boundary layer wind tunnel to produce a more realistic model of natural wind than that obtained in conventional aeronautical wind tunnel. Reports tests made tofind wind velocity profile and model tests to find dynamic response to wind loads and local pressures on buildings. Finds aeroelastic model response in turbulent flow is markedly different from that in smooth uniform velocity. Concludes that adequate simulation of natural wind has been obtained. Finds comparison between model and full-scale tests is encouraging.
Discusses problem of assessing wind loads on buildings. Describes general properties of the wind and suggests wind can be described by its mean velocity with superimposed gusts. Suggests averaging period of 10-15 minutes for the mean velocity. Gives empirical expression for wind spectra. Considers relationship between extreme value of wind speed and the parent distribution. Suggests influence of gusts is not best determined by maximum gust speeds. Finds mean wind speed profile and turbulent structure are strongly dependent on terrain.
Reviews some previous work on the measurement of wind pressures at full-scale. Deals with some of the problems arising. Describes pilot investigation being made at State House, Holborn to develop suitable techniques and to study the effect of gusts on pressure distribution. Gives preliminary results and mentions problem of establishing a suitable reference pressure.
Reports wind tunnel investigation of the wind pressure on houses. Tests were made on model of traditional form with sides in the ratio 1:3 and 1:6, roof pitch of 14 and heights of 2,3,4 and 8 storeys. Results were obtained in the form of pressure coefficients which are transformed into isobars using spline interpolation. Gives diagrams showing pressure coefficients and isobars for each test.
In connection with the revision of the German specification for loads due to wind, DIN 1055, section 4, an extensive review of literature was carried out. The present report contains a chronological summary of the major research investigations in the field of aerodynamics of structures and the corresponding specifications for various different countries. The historical development of wind load research, the considerations and the tests, which served as a basis for the German specification as well as aerological problems are briefly discussed.
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