Summarizes measurements made on a flat. These include inside to outside temperature and pressure differences, infiltration rates using helium as a tracer gas, duration of opening windows and doors and weather conditions. Also describes wind tunnel measurements made on a model of the building with and without obstacles and terrain roughness.
Reports measurements of air pressure differences to determine influence of wind on air flow directions through door and window gaps. Studies measures to prevent air transport between the 4 wings of the cross-shaped hospital and to ensure air flows from the corridors to the rooms on both sides. Pressure differences measured between facades agreed well with wind-tunnel results. Air flow directions measured agreed with results from an electrical analogue ventilation model.
Describes experimental techniques used in the low-speed wind tunnels at the Building Research Station when studying air flow around buildings and pressure distribution over their surfaces. Includes flow visualisation both in the stream and in boundary layers over surfaces, velocity measurements around small-scale models, and methods of building models containing pressure tappings. Gives names of suppliers and details of some instruments and equipments. Describes in an appendix how a simply constructed heated-sphere anemometer is made.
States that to obtain accurate estimates of wind induced natural ventilation of buildings the pressure distribution over the building is required. Reviews the available information for isolated buildings and groups of buildings. Gives the results of wind tunnel measurements made on a cuboid when surrounded by buildings of the same shape. Results are presented statistically and indicate that the pressure distribution on a building can be fairly accurately determined provided the density of the built form and the roughness fetch are known.
Full scale measurements were made of wind pressures on the 177m high post office tower, London. The variation of pressure with height was studied from recordings made at nine different levels between 49m and 168m above ground level. It is suggested that wind speeds of greater magnitude than those at the top of the tower sometimes occurred at lower levels.
Analyses theoretically the natural ventilation of buildings. Derives fundamental formula for the amount of ventilation due to temperature difference from Bernouilli's theorem considering buoyancy. Explains physical meaning of friction loss and theneutral zone, derives pressure distribution due to wind from the shape of buildings and the location of openings. Obtains total expression for amount of ventilation due to both temperature difference and wind.
Notes importance of air motion in shielded buildings in hot and humid climates. Describes wind-tunnel investigations on shielding effect of buildings for a group of buildings comprising parallel rows of identical blocks. Also considers influence of cross-ventilation through shielding building and variations in relative heights of the buildings. Discusses variation of wind speeds inside shielded building related to its distance from shielding building. gives optimum distances of separation for maximum and minimum shielding effect.
Describes experiments in a wind tunnel on a model of a tall building of rectangular plan to show the effects of variation in wind velocity with height and the variation of local wind pressures with angle of wind. Discusses the effect of rounding the corners of the building.
Compares wind pressures measured on a single-family dwelling with results obtained from a 1:50 scale model in a turbulent boundary layer. Shows that fluctuating components of surface pressures far exceeded mean or steady pressures and are well correlated over sizeable roof areas. Suggests that certain current provisions are marginal for tributary areas and excessive for localised area such as ridges, eaves and corners. Describes procedure for expressing loads on both localised and extended roof areas in terms of mean pressure coefficients and a peak factor.
Describes method for simulating natural wind boundary layer in a conventional, short working section, aeronautical wind tunnel. Boundary layers, which may be as thick as one-half of the working section height are generated by spires at the working section inlet. This approach is used to measure mean wind pressures and pressure spectra on a model of a tall building in downtown Montreal. Measurements are repeated using the long roughness fetch technique for boundary layer generation and results from the two methods compared.
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