This paper describes a set of velocity measurements which were made within a series of models of rectangular enclosures whose dimensions in plan were varied, the heights of the walls being held constant. The airflow's speed was measured at each of the points of a rectangular grid and the arithmetic mean of these measurements was adopted as a measure of the enclosure's performance in providing shelter from the wind, and was used to compare the effectiveness of one geometry against another. It was found that the degree of shelter could be optimised by a correct choice of geometry.
The appearance of bubbles used for flow visualisation around bluff bodies in a wind tunnel is illustrated. It is demonstrated that the large diameter and low density properties of bubbles could enable them to represent raindrops in a wind tunnel.
Gives detailed results of an extensive programme of wind tunnel testing of a standard scale model of a one-room, flat-roofed building. A major requirement was coverage of those characteristics of window openings or window accessories which were known (or which appeared) to have a significant effect on indoor air flow.
The thermal effects of air flows in building structures have been analyzed by computer simulation. Some laboratory experiments have also been carried out concerning natural convection in closed and semi-open cavities filled with fibrous insulating material. Three different flow systems in building structures have been studied: natural/forced convection in open/semi-open (permeable cold surface) 2-dimensional insulation structures, heating of infiltrating air in cracks and diffusive infiltration.
Models are defined for various mixing conditions, in continuous flow systems. Differential equations are derived which take into account aneffective volume of mixing, possible short-circuiting, hold-up time of the system, partial displacement or piston flow. The values of the different factors contained in the integrated equations can be determined experimentally by the particular response of a given system to a sudden change in composition of the feed. A correlation of the effective volume of mixing and the agitator r.p.m. is presented.
One important factor in the spread of airborne infection must be the movement of the air itself i.e. the ventilation, although an exact correlation of it with the risk of infection has yet to be found. As part of an infection survey in a hospital ward we made a detailed study by physical methods of the movements of the air and of the transport of particles by this means. A description is given of the methods employed.
This paper describes an original investigation of a new flowmeter and a method of balancing of airflow circuits in low pressure ventilating systems. The flowmeter is simple and robust in its construction, imposes virtually no resistance to
The pressure drop and flow characteristics of short capillary tubes have been investigated experimentally for length-to-diameter ratios varying from 0.45 to 18 at diameter Reynolds numbers ranging from 8 to 1500. In the range of the dime
The growing interest in the response of structures to turbulent wind forces and the realization of the important role played by root-coherence in the prediction of such response has led to the proposal of several expressions for the power
The effect of ventilation in the space between a main wall and an exterior siding is examined with respect to reducing the building's cooling load. The buoyant force of the air in the space is considered as the motive force of air flow and the effect is treated as a problem of simultaneous heat and mass-transfer. A simulation program of heat and air flows in a wall has been developed using laminar flow theory, and its validity is examined by thecomparison of the simulation results with a weather exposed full-scale model test.
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