![]() In this paper, a vertical cylinder model of wind chill has been modified so that just the cooling of its windward side is considered. Wind chill has sometimes been modeled as the overall heat transfer from the surface of a cylinder in cross flow, but such models average the cooling over the whole surface and thus minimize the effect of local cooling on the upwind side, particularly at low wind speeds. The latter was based on experiments with a heated model of a face in a wind tunnel. Wind chill equivalent temperatures calculated from a recent vertical cylinder model of wind chill are several degrees colder than those calculated from a facial cooling model. Windward Cooling: An Overlooked Factor in the Calculation of Wind Chill. A comparison of hourly and daily mean values show that the means do not indicate the real range of wind-chill during the day. Thessaloniki does not experience “frost-bite†conditions during the coldest months but does experience “warm†conditions during the summer period. The values of wind-chill are discussed in terms of Terjung's scale. The hourly values of wind-chill were calculated by Siple-Passel's formula which still appears to be most widely used. This is the first attempt in Greece to describe bioclimatic conditions using wind-chill data. The diurnal variations of wind-chill at Thessaloniki, Greece, are considered using hourly data from January 1960 to December 1977. The combined effect of these two factors is to overestimate the effect of a given wind velocity and to predict a wind chill temperature that is too low.ĭiurnal variation of wind-chill at Thessaloniki, Greece The resultant equation for the wind chill temperature assumes an unrealistic constant skin temperature and utilizes heat transfer coefficients that differ markedly from those obtained from equations of modern convective heat transfer methods. The currently used wind chill factor was found to be based on a primitive study conducted by the U.S. As this wind chill factor has social and economic significance, an investigation was conducted on the development of this factor and its applicability based on modern heat transfer principles. Meteorologic charts provide wind chill temperatures meant to represent the hypothetical air temperature that would, under conditions of no wind, effect the same heat loss from unclothed human skin as does the actual combination of air temperature and wind velocity. The wind chill factor has become a standard meteorologic term in cold climates. An evaluation of the wind chill factor: its development and applicability.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |