- : # l 6 ooc 4405 Ventilation and Air Quality in Indoor Ice Skating Arenas
There are thousands of indoor ice rink arenas in the United States, Canada, and Europe. The combustion byproducts from the feel-powered ice resurfacing equipment are a potential health risk to both athletes and spectators. A field survey of ten ice rink arenas in Greater Boston and Halifax, Nova Scotia, indicates that the fael type used by the resurfacer as well as the air exchange rate, the air distribution method, and the operation strategy of the ventilation system are significant contributing factors to the indoor air quality (JAQ) . Computational fluid dynamics (CFD) has been used to systematically investigate the impact of the air exchange rate, air distribution method, and ventilation control strategies on the IAQ in an arena. With CFD, it is possible to develop design and operating guidelines for ventilation systems in order to reduce contamination levels in the arenas.
An experimental method for contaminant dispersal characterization in large industrial buildings for IAQ applications.
Spatial contaminant distribution in large semiopen building areas such as sports arenas, warehouses, atriums, malls and other industrial halls is critical to estimating exposure, health risks and building energy performance. It is considered a challenge to measure experimentally how effectively the ventilation system removes or dilutes the pollutant in a large open space, taking into consideration the usual non uniformity of the air flow created by local heat and contamination sources, geometrical obstructions and the air distribution system. An experimental method is presented in this paper which can be used for both the experimental evaluation of ventilation effectiveness as well for CFD modeling validation in large open space applications. The developed method which is based on a passive perfluorocarbon tracer gas (PFT) system previously used for infiltration measurements in homes has been successfully used for the experimental evaluation of ventilation effectiveness in an ice skating arena in the Boston area and for the validation of a developed CFD model for the analysis of the IAQ in ice rink facilities. The method is very easy to use, fast and fairly inexpensive and it does not interfere with human and other activities within the building environment.
Turbulent boundary layer wall‐pressure fluctuations downstream from an abrupt change in surface roughness
Spectra of wall‐pressure fluctuations beneath a turbulent boundary layer have been investigated immediately downstream from an abrupt change in surface roughness, from slightly rough to very rough. Over the measurable frequency band (400 Hz to 7 kHz), the spectra in the first 150 mm scale on wall variables. This indicates that the motions responsible for the pressure fluctuations measured in this region are very close to the wall. Farther downstream this scaling procedure breaks down. It is suggested that the initially thin internal layer behaves independently of the flow external to it until it has grown appreciably and only then interacts with the outer boundary layer. It was found that, for all frequencies measured, the dimensional spectral level decreases initially then rises to a maximum at 250 mm from the roughness change before decreasing once more. The position of the maximum is close to where the internal layer ceases to have a distinct edge.