Human Thermal Model Expressing Local Characteristics of Each Segment

Shintaro Yokoyama, Takafumi Maeda, Masashi Kuramae, Naoto Kakuta
2007 Journal of the Human-Environment System  
Introduction The laboratory to which the authors belong studies heat transfer between humans and the environment, and lists the evaluation and control of indoor thermal environments among its traditional research subjects. This paper describes the genealogy of research on those subjects and related human thermal models, and presents the research results obtained recently in the laboratory. Development of a thermoregulatory model expressing local characteristics of each segment of the body
more » ... an epoch of research on human thermal models. Its purpose is to link the thermoregulatory model with a thermal environment measuring system equipped with a microprocessor, and use them for achieving optimal environmental design, evaluation and control through the process of evaluation and prediction of thermal environments. Subjects presented in past papers on this model include a method for estimating local heat generation as a basic point and estimated values based on it, the heat transfer equation in the human body, a mathematical model of the controlled output of the thermoregulatory system, calculation algorithm of the heat balance equation for the entire vascular system, a highly accurate con-trolled object-type database, warm-cold sensitivity based on the calculated value of in vivo temperature, prediction of thermal comfort and the results of several numerical simulations. There are actually a variety of heat transfer phenomena, such as thermogenesis, heat storage, thermal conduction, blood advection, heat transfer from vascular walls, respiratory heat loss from the lungs, convective, radiative and evaporative heat transfer on the body surface, and thermal conduction with contact surfaces. With the intention of making some contribution to the development of this field, this paper reviews the fundamentals of human thermal models with focus on the genealogy of research conducted by our predecessors, as well as on the results obtained in relation to local characteristics of each segment of the body. Thermal comfort equation and the two-node model Evaluation methods based on thermal equilibrium between humans and thermal environments, which are frequently used in the world today, include the thermal comfort equation (Fanger, 1970 (Fanger, , 1982 of the Technical University of Denmark and the two-node Abstract We discussed the present research trends of mathematical models of heat transfer phenomena within human body. In addition we introduced our mathematical model expressing local characteristics of each segment including a subroutine of calculation of physiological thermoregulatory responses. By using this computer program several simulations under various combinations of thermal environmental conditions and working levels were performed. The calculated results were agreed with the measured results and suggested the validity of the present mathematical model to evaluate human responses.
doi:10.1618/jhes.10.51 fatcat:zhbyamd2zfffpdtbucununabpe