Reports investigation of mean and fluctuating pressure inside buildings, induced by wind using boundary layer wind tunnel and computer simulation techniques. Mean and root-mean-square fluctuating internal pressure coefficients were both found to be monotonic functions of the ratio of windward to leeward opening areas.< The case of a single windward opening was treated as a damped Helmholtz resonator.
Compares full-scale pressure coefficients obtained from a 57-storey building in Toronto with wind tunnel results for tests in the 9m by 9m wind tunnel at the National Research Council of Canada. Demonstrates good agreement where sufficient full-scale data exists. Proposes a method of treating peak pressures based on the fit of an exponential distribution to a population of "significant independent events", called pressure spikes. This distribution provides a good fit to both full-scale and wind tunnel results, which generally agree.
A short note giving formulae for the design of spires for use in simulating the planetary boundary layer. Gives expressions for the height and base length of triangular spires which will produce given values of the boundary layer thickness and power-law exponent. Gives comparisons of calculated values with experimental data.
Describes a covariance integration method for the determination of fluctuating overall structural loads due to wind and their effects on low rise buildings. The required aerodynamic information can be obtained from boundary-layer wind tunnel tests: static structural influence coefficients are also required. Themethod is an alternative to the direct on-line weighting technique, but is less demanding on wind tunnel instrumentation and data acquisition facilities. To obtain peak values, Gaussian probability distributions have been assumedfor the loads or their effects.
Gives a brief historical review of the development of wind engineering as a discipline. Discusses the simulation of wind loads on buildings, the development of boundary layer wind tunnels and problems in modelling the natural wind. Describes modelling of the aerolastic behaviour of buildings andof stack gas diffusion. Describes instrumentation and measurement techniques. Indicates areas requiring further development.
Describes further experiments from the wind tunnel simulation of wind pressures on the Aylesbury housing estate. These experiments are not concerned with the acquisition of further data, but are designed to examine the validity of measurements.< Discusses the effect of varying observation and averaging times. Reports results of experiments, varying these times, but finds no observable trends in the dispersion results.
Reports root mean square and extreme pressure measurements made on a model of the Aylesbury housing estate in the Oxford wind tunnel. Also presents a complete set of measurements on the test house alone, corresponding to the varied roof pitch records. Presents extreme value data in the form of a Fisher-Tippett type probability function.< Discusses design of the experiments, experimental procedures and results. Gives 47 tables comparing full scale with wind tunnel results. Includes results of wind tunnel measurements made at Bristol University.
Describes the first stage of an investigation designed to simulate in a wind tunnel the full scale wind pressure measurements made by the Building Research Establishment on the Aylesbury test house. Describes in detail the wind tunnel, instrumentation, measurement techniques and experimental procedures. Discusses the problems of simulating natural wind.< Discusses the results of measurements of mean pressure coefficients. Compares results with full scale measurements and results of a wind tunnel simulation made at the University of Bristol.
Reports wind tunnel measurements of the wind-induced internal pressures of models of low-rise buildings of different geometry and internal volume. Three different uniform porosities (0.0 0.5 and 3.0% of the total surface area) have been examined in combination with openings in a wall ranging from 0 to 100% of that wall's area. Two terrain roughnesses were used corresponding to open country and suburban regions.< Finds that internal pressures are variable but generally lower than local external pressures.
Describes the operating characteristics of a small aspirated concentration sensor based on a hot-film anemometer. Constant aspiration velocity past the sensor produces a linear output over a wide range of tracer gas concentrations, and a useful bandwidth of 0-500 Hz. A simple experimental technique for dynamic calibration is presented, with frequency response inferred from a model of the effects of molecular diffusion and hot-film response.
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