Discusses flow of air between two rooms through an open door. Considers 6 cases with and without mechanical ventilation and with a temperature difference between the two rooms. Gives examples of the calculation of air flow. Recommends that for hospitals where the transfer of bacteria should be avoided, doors should be kept shut as much as possible and that it is not economically justifiable to choose such a high ventilation rate that no undesirable back flow occurs with the doors open.
An earlier paper gave the flow to be expected through an open door from theoretical considerations. Describes model tests designed to check these theoretical predictions. The model used was 6.3% of full size and water was used instead of air for the flow medium. Concludes there is reasonably good agreement between model and theory.
Steeply sloping ventilated roofs are preferred for single and two-family houses in West Germany. Notes lack of any scientifically substantiated notions concerning physical laws governing air exchange between ventilated zones and outside air. Describes air flow and heat transfer investigations in a 48 deg. sloping roof. Gives details of roof constructions. Illustrates roof space and distribution of thermocouples and arrangement for injecting tracer gas. Describes experimental procedure. Provides some measurement results. Compares theoretical bases with experimental results.
Presents the results of a series of wind tunnel tests in which the surface pressure fields of low-rise buildings have been studied. These tests start with an examination of how the body shape influences the surface pressures for a range of isolated bodies. The test results then go on to describe how theparameters which describe an array of such model buildings influence the surface pressures.
Describes method for calculating the adventitious ventilation of a building using information from a pressurization test. The method requires a knowledge of the surface pressures on a building, calculated from wind speed and direction, the inside-outside temperature difference, and the distribution and characteristics of openings in the building shell. Applies formulae to threebuildings and finds a great dependence of infiltration on wind direction. Discusses the effect of wind and stack effect, separately and combined.
Describes the development of an anemometer for the measurement of rapidly fluctuating air flows. Describes the B.R.E. shielded hot wire anemometer. Discusses modifications made to this anemometer to improve its response by using different shields and moving sensor wires closer together. Outlines system for processing signals from the anemometer using a micro-computer. Gives results of performance tests. Gives simple applications of theinstrument.
Briefly surveys past work on wind tunnel measurements on the surface pressures on low rise buildings. Describes experimental investigation of the surface pressures on an isolated model. Discusses results of flow around a model of varying height and aspect ratio, and the influence of upstream fetch on surface pressures. Gives figures showing recorded pressure coefficients and details of pressure tappings on the various models.
Considers the characteristics of flow through small gaps. Discusses relation between wind tunnel measurements and actual wind pressure on buildings and the effect of building shape on ventilation. Derives equations for flow rate through a gap for different temperature and pressure differences and sizes of gap. The equations consider the pressure as a function of time thus modelling the effects of a turbulent wind incident on a gap.
Measurements have been made of the air-leakage rates through structural components of conventional metal-panel and concrete buildings which may serve as containment for nuclear reactors. The component measurements included structural penetrations such as doors and louvers as well as materials such as caulking compounds, gaskets, and paints. Specimens were sealed inside of test vessels.
CAFE is a suite of computer programs, developed by Atkins Research and Development, to solve engineering problems involving fluid flow and heat transfer. Based on a finite difference method, its main advantage over other programs is its generality, which enables problems requiring a variety of different boundary conditions to be studied.< Describes the mathematical formulation of the program and its major features. Gives examples of its application including modelling the ventilation of a building to reduce concentrations of dangerous gases.
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