Fundamental study of ventilation in air layer in clothing considering real shape of the human body based on CFD analysis

Abstract

To properly predict thermal comfort using a thermal model of the human body, heat and moisture transfer in and around clothing as well as the thermophysiological response of the human body must be evaluated. Among the phases for modeling heat and moisture transfer in and around clothing, ventilation in the air layer in clothing is one of the most difficult elements to quantify. The low air velocity in clothing and the complex shape of the air layer complicates measurement. In this study, computational fluid dynamics (CFD) analysis around the human body considering the air layer in clothing was conducted instead of measurement. By importing three-dimensional (3D) shape data obtained by a laser scanner, the air distribution in and around clothing was observed by CFD analysis, for an adult human wearing single-layered clothing in typical indoor environmental conditions. The typical characteristics of the air flow around a clothed human body were clarified, and the influence of the ventilation of clothing air layers on the heat flux at the skin surface under the clothing was determined to be minimal. In addition, the results of the CFD analysis were consistent with those of a thermal manikin experiment, validating the CFD analysis.