Airflow through a building has both mean and fluctuating components due to spatial and temporal variations in wind-induced pressures. Most of the existing investigations consider the average values of wind pressures and predict steadystate solutions for airflow [1]. This paper presents some experimental results for the validation of a proposed fluctuating airflow model [2]. The new model employs spectral analysis and statistical linearization methods to model the pulsating airflow through buildings.
Shows that the interior pressures in buildings are amenable to more detailed analysis than is conventionally given them and that useful information on them can be easily derived from the wind tunnel data on external pressures. The uncertainties can be expressed in parallel statistical terms. The importance of fluctuating pressures are related to the area of the opening and interior volume and a simple criterion indicates when these are likely to be important.
A knowledge of the pressure fluctuations on buildings exposed to strong winds is important for wind loading calculations. Presents the statistical quantities of such fluctuations in terms of rms values and power spectra for models resembling the Aylesbury experimental building of BRE, and compares this with full-scale results. Suggests that, provided the properties of the longitudinal velocity component are suitably simulated, then agreement between full-scale and model results in terms of rms values and power spectra can be achieved.
Reports measurements of wind pressure distributions on a model of tall building made in a turbulent wind tunnel with a velocity gradient. The wind pressure distributions in a constant uniform velocity field were also measured and the differences in thepatterns of pressure distributions due to the effects of velocity gradient were observed at lower part of the model.< Also describes measurement of natural wind pressures and glass strains on a 36 storey office building. Finds inter alia considerably large pressure fluctuations of short gusts although average pressures are small.
Reports an investigation of wind loading with emphasis on the local pressure fluctuations, on a small scale building model in a thick turbulent boundary layer wind tunnel. A striking similarity between the oncoming turbulent energy spectra andsurface pressure-fluctuation spectra was consistently observed. This similar behaviour suggests that the upstream turbulence plays a dominant role in producing the pressure fluctuations on the upwind face of a bluff body.
Gives a brief account of exploratory efforts to isolate the contributions of flow separation and reattachment to local surface pressure fluctuations. The study is restricted to tall buildings with sharp vertical edges. Pressure fluctuation measurements were made on small scale models of actual buildings placed in uniform flow of low turbulence level. Gives figures showing mean and root-mean-square pressure coefficients. Finds maximum instantaneous pressure fluctuation was four times the root-mean-square value. Describes characteristics of pressure fluctuations.
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