Wind Penetration through Fabric Systems. Part I

Abstract

Total and local heat transfer coefficients obtained on heated cylinders under similar environmental conditions of wind speed and air temperature are used as "figures of merit" for comparing fabric systems with different partitional dimensions and material compositions and covered by windbreaks of different permeability. It was found that two moderately air permeable windbreaks with a space between them could provide protection from wind penetration equal to or greater than a single windbreak of low permeability. It was also shown that the variation in heat loss around the cylinder was much greater with certain arrangements of fabric layers than with others even though the average (over-all) coefficients were often the same. This suggests that comparisons of fabric systems based on average or over-all insulating values may be highly misleading, since no indication of potential "cold spots" in a wind (particularly on the windward side) is possible.