Heat and Moisture Transfer between Human Body and Environment [Hardcover]

Human adaptation under cold or hot temperatures has always required specific fabrics for clothing. Sports or protective garment companies propose to improve performance or safety. Behind thermal comfort lays many physical/physiological topics: human thermoregulation loop, natural or forced convection, heat and vapor transfer through porous textile layers, solar and infrared radiation effects. This book leads through progressive and pedagogic stages to discern the weight of all the concerned physical parameters.

Preface ix

Chapter 1. Building a Model for a Coupled Problem 1

1.1. Basic equations of the models (Appendix 1) 2

1.2. Boundary layers 3

1.2.1. Forced convection 4

1.2.2. Natural convection 6

1.3. Heat balance for a “system” and boundary conditions 8

1.4. On the problem of cooling of a cup of tea 11

1.4.1. Balance equations 12

1.4.2. Research of transfer correlations13

1.4.3. Surface temperature as a function of average temperature of the liquid 15

1.4.4. Liquid temperature as a function of time 16

1.5. Bather on a beach 19

Chapter 2. Approximate Determination of Transfer Coefficients 25

2.1. Natural convection around an isolated sphere 25

2.1.1. Equations of boundary layers depending on velocity and temperature 26

2.1.2. Integration over the boundary layer thickness 28

2.1.3. Dimensionless formulation 32

2.1.4. Numerical solution 33

2.2. Coupled exchanges around the head of a baby lying down 37

2.2.1. System of equations 38

2.2.2. Boundary layers for the horizontal disk 40