After a general introduction on the cause of wind, the dependence of wind speed increase with height on surface roughness and atmospheric stability is discussed. For the purpose of wind load calculation on structures this speed increase is often approximated by the pth power of height where the exponent p varies both with roughness, stability and the height of the layer in question. The last mentioned variation implies that extrapolations of p above its determination height cannot be depended upon.
Presents results obtained from a digital analogue method of calculating infiltration rates in building. The results are compared with a set of full-scale observations carried out by G.T.Tamura and A.G. Wilson. (abstract no.192). Finds that calculated and full-scale results give good agreement in terms of the rate of change of air infiltration rate with wind speed and that both show that total infiltration rate is more sensitive to wind speed than wind direction.
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.
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.
Ventilation rates in two test home were measured using helium as a tracer gas. Pressure differences across the exterior walls of the house were recorded using pressure taps. Gives results for air infiltration tests and the calculated air infiltration. Finds that during summer air infiltration rates varied approximately linearly with wind velocity. During the winter, the pattern and extent of air infiltration were influenced by both house stack action and furnace operation.
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.
States heat load on buildings due to wind is dependent on the shape of building, wind direction and wind speed. Gives theoretical calculation for the heat loss due to wind based ongerman standard DIN 4701. Discusses fundamentals of fluid dynamics and the practicalities of wind tunnel tests. Recounts tests made of a block of flats in Munich. Pressure distribution due to wind was determined by a wind tunnel test on a model, giving c-profiles for different wind directions.
Describes experiments made to determine the air infiltration rate through revolving doors. Estimates infiltration by combining air leakage past the door seals with infiltration caused by the revolving of the door. Finds that air exchange depends on door speed and temperature differential and somewhat on wind and indoor air velocities. Gives flow past the door seals as function of indoor -outdoor pressure differential and flow related to door movement for a motor- driven revolving door and for a manually operated door for traffic rates up to 2000 people per hour.
Gives method for calculating infiltration of a building due to wind and stack effect. Uses equations from ASHRAE guide of 1958, but resolves wind vector into horizontal and vertical components and takes the angle between wind and ground into effect. Method is used to calculate infiltration due to wind for a given building of height h at a distance d from the nearest building with height c and a sample calculation is given
Gives measurements of air infiltration made in ten houses in Indiana using helium as a tracer gas. Assumes linear dependence of infiltration rate on temperature difference and wind velocity and calculates infiltration rate per unit crack length. Change rates ranged from about 0.6 to 1.5 changes per hour.
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