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.
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.
Describes a photo-electric technique for instant determination of contaminant concentration in wind tunnel studies of stack gas dispersion. A roving sensor is used to measure the light scattered by the particles of oily aerosol representing theprototype stack effluent. The minature probe has a noise level of only one hundred thousandth of the full linear range of the output signal for a time constant of 5s. Device is also suitablefor measurement of fluctuating flow properties, such as turbulence, where a high frequency response is required.
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.
In 1978 the Swedish parliament adopted a ten-year "energy saving plan for existing buildings". Outlines energy saving measures which qualify for public support. Describes survey made of randomly chosen buildings, which had received loans or subsides, to evaluate their effectiveness. Describes collection of information and gives method for calculating energy savings. Reports preliminary result that extra attic insulation leads to substantial energy saving as did replacement of boiler and burner in multi-family homes.
Presents measurements of the mean and fluctuating pressure field acting on two-dimensional square cylinder in uniform and turbulent flows. Shows the addition of turbulence to the flow raises the base pressure and reduces thedrag of the body. Suggests this is attributable to the manner in which increased turbulence intensity thickens the shear layers, which causes them tobe deflected by the downstream corners of the body and results in the downstream movement of the vortex formation region.
Describes experimental techniques used to produce turbulent boundary layers in a wind tunnel. Gives model law for velocity profile in a turbulent flow over a rough surface. Describes wind tunnel, five tunnel coatings used to generate turbulence, themodels and instrumentation. Gives as an example the test results from a model of house with desk roof.
Sets out the similarity requirements which must be observed so that results of wind tunnel tests may be used to predict behaviour of full-scale prototypes in the natural wind. Discusses rigid models, suspension bridges, models of slender towers. Outlines problems of representing natural wind and the effect of wind tunnel-wall interference. Introduces correction procedure for wake blockage which permits the use of larger wind-tunnel models than would otherwise be possible without serious errors.
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.
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.