Heat Transfer from the Human Body in Hyperthermic, Low Gas-Velocity Environments

摘要

The authors studied the physics of heat transfer from the human body under conditions of low air velocity (LAV). For 1 ATA, the authors calculated values of the evaporative heat transfer coefficient of 5.24 and 5.37 where ambient temperature/relative humidities, were 38 C/70% and 35 C/80%, respectively, and ambient velocities of 0.06 m s-1 in both cases. This is near our newly conceived minimum value of 4.94, significantly greater than the 2.8 and 3.4 values that are calculated using the Lewis relation. The authors further described an iso-vapor pressure temperature difference, which transcribes a water vapor pressure difference into a temperature difference, thus allowing use of classical nondimensional analysis to account for the increasing importance of heat loss through evaporation on LAV. Water vapor pressure differences in LAV hypobaric environments will account for increased heat losses.