人体に関する対流およびふく射熱伝達率

Abstract

A general equation to give mean convective heat transfer coefficient for the human body was theoretically derived based on the heat balance between man and his environment. The equation is weighted with the local convective heat transfer coefficients and the area ratios of the human skin. Under hot and high air velocity conditions, with the above equation derived and Hilpert's equation of forced convective heat transfer, eighteen centimeter was obtained by the reverse calculation as the diameter of a man-equivalent cylinder from the standpoint of heat transmission. Further, by applying Oosthuizen-Madan's equation which considers both natural and forced convective heat transfer at the same time to the cylinder with eighteen centimeter in diameter, an equation of convective heat transfer coefficient for the human body was proposed and compared with the values of the convective coefficients by earlier workers. A radiative heat transfer coefficient and a radiant temperature with new concepts were derived by extending Gebhart's absorption factor method on radiant heat exchange and by applying it to the space between the human body and the surrounding walls and by linearizing from the so-called raising to the fourth power radiation law. The new radiative heat transfer coefficient is consisted of the emissivity of the human body surface, Stefan-Boltzmann's constant and the temperature factor. On the other hand, the new mean radiant temperature is weighted with the absorption factors between the human body and the surrounding walls.