Reports wind tunnel tests of wind velocity, RMS velocity fluctuations and energy spectra for the streamwise velocity component in the lee of model fences of permeability 0% 20%, 34% and 50%. Compares results with existing field and wind-tunnel data. Turbulence measurements define the leeward flow regions which are dominated respectively by the bleed flow and by thedisplacement flow. Gives separate empirical relationships between mean velocity and turbulence intensity for these two regions.
Reports the results of three programmes of measurements of ventilation carried out in one-family houses, which in most cases were of the 'council house' type. The first programme measured ventilation rates using tracer gasin two houses room by room. Wind speed and direction were recorded but no general relation between ventilation and wind was found. The second measured ventilation rate in individual rooms in a house under six different wind conditions. The third measured ventilation rates in three identical homes.
Describes computer program developed by BSRIA to predict ventilation rates and directions of air flow in buildings for given sets of conditions. These conditions are wind speed and direction, temperature differences between inside and outside the building, air leakage characteristics of the components and the mechanically induced air flow rates. The report is in the form of anoperating manual for the program.
Describes technique for measuring the volume of air leaving a house through the loft. Two tracer gases are used; nitrous oxide is released in the house and carbon dioxide in the loft. The mean concentration of N2O in the loft gives the volume of house air infiltrating the loft: and the mean concentration of CO2 gives the ventilation rate of the loft itself.< Gives two examples of the use of this technique and gives loft ventilation rate as a function of wind speed for one house.
Describes computer program for the prediction of the air infiltration load in small residential buildings. The model represents an oil-fired furnace, a smoke pipe with barometric damper, a chimney and a non-partitioned building, with leakage openings in the building envelope. The model can be used to predict the air change rate of a small house under various combinations of indoor/outdoor temperature, wind-speed, wind direction and operation of an oil fired furnace.
Reports measurements made in six blocks of flats of energy consumption and wind speed. Gives graphs of results. Concludes that a moderate wind (of 30m/s) increases energy consumption by12% and a strong wind (60m/s) by 25%. Suggests heat loss can be reduced by tightening windows and controlling ventilation.
Natural ventilation of inhabited rooms is studied with regard to its dependence on wind velocity and temperature difference between the interior of buildings and outside air. On the basis of simultaneous aerosol and carbon dioxide measurements an attempt has been made to separate the two components of air exchange: ventilation through walls and ventilation through clefts and chinks.
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.
Reports wind measurements made on a multi-storey building. Gives contours of overall pressure coefficients and wind velocity profiles. Compares results with series of wind-tunnel model tests and finds full-scale measurements were quite different from model tests. In an attempt to gain greater physical insight into the problem tests were made on a two-dimensional bluffplate immersed in a turbulent boundary layer. Finds correlation of drag coefficient with boundary layer parameters for quasi-equilibrium type layers.
Describes both the macro and micro meteorological structure of strong winds in the earths boundary layer. Discusses the wind speed spectrum, characteristics of mean flow and gustiness and the structure of turbulence. Concludes that almost all theproperties of the wind that might be needed in structural design can be estimated from the mean-wind field and the groundroughness. Suggests areas for further research.
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