Textiles and Human Thermophysiological Comfort in the Indoor Environment | Radostina A. Angelova

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Textiles and Human Thermophysiological Comfort in the Indoor Environment
By Radostina A. Angelova

Textiles and Human

Contents
List of Figures ……………………………………………………………………………………….. xvii
List of Tables ………………………………………………………………………………………..xxvii
Preface ………………………………………………………………………………………………….. xxxi
Author …………………………………………………………………………………………………xxxiii
Section I Interaction of Textiles and Clothing with the Environment and Man
1. Human Comfort: Thermophysiological Comfort ………………………………3
1.1 Role of Textiles and Clothing ……………………………………………………..3
1.2 Human Comfort …………………………………………………………………………4
1.3 Physiological and Thermophysiological Comfort ……………………….5
1.3.1 Physiological Comfort …………………………………………………….5
1.3.2 Thermophysiological Comfort ………………………………………..6
1.3.2.1 Phases of Thermophysiological Comfort …………..6
1.3.2.2 Terms Associated with
Thermophysiological Comfort ………………………….7
1.4 Summary ……………………………………………………………………………………9
2. Textiles and Clothing in the Indoor Environment ………………………….. 11
2.1 Interaction between the Human Body and the Indoor
Environment ……………………………………………………………………………. 11
2.2 Textiles in the Indoor Environment …………………………………………. 13
2.2.1 Risk Factors in the Indoor Environment ………………………. 13
2.2.2 Floor Coverings ……………………………………………………………. 15
2.2.3 Upholstery Textiles ………………………………………………………. 17
2.2.4 Bedding and Blankets ………………………………………………….. 18
2.2.5 Curtains and Screens …………………………………………………… 18
2.3 Summary …………………………………………………………………………………. 19
3. Thermal Insulation Properties of Textiles and Clothing ………………… 21
3.1 Hierarchical Structure of Textiles …………………………………………….. 21
3.2 Heat Transfer through a Textile Layer ………………………………………22
3.2.1 Dry Heat Transfer …………………………………………………………23
3.2.1.1 Conduction ……………………………………………………..23
3.2.1.2 Convection ………………………………………………………23
3.2.1.3 Radiation ……………………………………………………….. 24
3.2.2 Impact of the Hierarchical Structure on the Dry Heat
Transfer ………………………………………………………………………… 24
3.2.3 Latent Heat Transfer ……………………………………………………..25
3.2.4 Impact of the Hierarchical Structure on the Latent
Heat Transfer ………………………………………………………………..26
3.3 Transfer of Fluid through a Textile Layer ………………………………….27
3.4 Thermal Insulation of Textiles and Clothing …………………………….28
3.5 Factors That Influence the Thermal Insulation of the Textiles …..29
3.6 Methods for Determination of Thermal Insulation
Properties of Textiles ……………………………………………………………….. 32
3.7 Thermophysiological Comfort and Special Textile Materials
and Garments …………………………………………………………………………..33
3.7.1 Silver Fibers…………………………………………………………………..33
3.7.2 Carbon Fibers ……………………………………………………………….34
3.7.3 Phase-Change Materials ……………………………………………….34
3.7.4 Application of Special Textile Materials ………………………..35
3.7.4.1 Active Wear …………………………………………………….35
3.7.4.2 Automotive Textiles ………………………………………..35
3.7.4.3 Outdoor Sports Clothing …………………………………36
3.7.4.4 Lifestyle Apparel …………………………………………….36
3.7.4.5 Aerospace Textiles …………………………………………..36
3.7.4.6 Medical Textiles ………………………………………………36
3.8 Summary …………………………………………………………………………………. 37
4. Interaction between Textiles and Clothing and the Human Body ……….. 39
4.1 Regulation of Body Heat ………………………………………………………….. 39
4.2 Mechanisms of Heat Loss and Heat Generation of the
Human Body ……………………………………………………………………………. 41
4.2.1 Mechanisms of Heat Loss …………………………………………….. 41
4.2.2 Mechanisms of Heat Generation …………………………………..42
4.3 Impact of Textiles in the Indoor Environment on the
Human Body …………………………………………………………………………….44
4.3.1 Effect of Chairs ……………………………………………………………..44
4.3.2 Effect of Bedding Textiles ……………………………………………..44
4.3.2.1 Duvets …………………………………………………………….45
4.3.2.2 Common Blankets …………………………………………..45
4.3.2.3 Electric Blankets ……………………………………………..46
4.3.3 Some Solutions for Improving the Effect of Textiles
on Human Thermophysiological Comfort …………………….46
4.4 Summary ………………………………………………………………………………….47
Section II Experimental Study of Woven Textiles
Used in the Indoor Environment
5. General Considerations and Methodology
of the Experimental Study ……………………………………………………………….. 51
5.1 Aims and Scope of the Experimental Study …………………………….. 51
5.2 General Description of the Study …………………………………………….. 52
5.2.1 Experimental Investigation of the Mesostructure ………… 52
5.2.1.1 Linear Density ……………………………………………… 52
5.2.1.2 Twist ……………………………………………………………..53
5.2.1.3 Width of Ribbons ………………………………………….53
5.2.1.4 Tenacity and Elongation at Break ………………….53
5.2.2 Experimental Investigation of the Macrostructure ……….53
5.2.2.1 Warp and Weft Density …………………………………53
5.2.2.2 Thickness ………………………………………………………53
5.2.2.3 Yarn Crimp……………………………………………………53
5.2.2.4 Fabric Weight ………………………………………………..54
5.2.2.5 Warp and Weft Cover Factor …………………………54
5.2.2.6 Fabric Cover Factor ……………………………………….54
5.2.2.7 Fabric Areal Porosity …………………………………….54
5.2.2.8 Air Permeability ……………………………………………55
5.2.2.9 Thermal Resistance ……………………………………….55
5.2.2.10 Liquid Transfer ……………………………………………..55
5.3 Calculation of the Relative Error ………………………………………………55
5.4 Summary ………………………………………………………………………………….56
6. Experimental Investigation of the Mesostructure …………………………… 57
6.1 State of the Art of the Problem: Impact of the Mesostructure
on the Transfer of Heat and Fluids …………………………………………… 57
6.2 Properties of the Yarns ……………………………………………………………..60
6.3 Manufacturing of Identical Woven Structures from
Different Yarns …………………………………………………………………………60
6.4 Analysis of the Effect of the Mesostructure on the Air
Permeability of the Macrostructure ………………………………………….65
6.4.1 Effect of the Linear Density …………………………………………..66
6.4.2 Effect of the Twist ………………………………………………………… 67
6.5 Analysis of the Effect of the Mesostructure on Heat
Transfer through the Macrostructure ………………………………………. 69
6.5.1 Effect of the Linear Density ………………………………………….. 69
6.5.2 Effect of the Twist ………………………………………………………… 70
6.6 Analysis of the Effect of the Mesostructure on Moisture
Transfer through the Macrostructure ……………………………………….71
6.6.1 Effect of the Linear Density …………………………………………..71
6.6.2 Effect of the Twist …………………………………………………………73
6.7 Summary …………………………………………………………………………………. 74
7. Experimental Investigation of the Macrostructure of Textiles
for Clothing and Bedding …………………………………………………………………75
7.1 Introduction ……………………………………………………………………………..75
7.2 Properties of the Macrostructures …………………………………………….75
7.3 Experimental Assessment of the Porosity ………………………………… 76
7.4 Experimental Assessment of the Air Permeability ……………………85
7.4.1 Analysis of the Air Permeability of Gray Fabrics…………..92
7.4.2 Analysis of the Air Permeability of Finished Fabrics …….93
7.5 Experimental Assessment of the Conductive Heat Transfer ……..94
7.6 Experimental Assessment of the Moisture Transport ……………….99
7.7 Summary ……………………………………………………………………………….. 102
8. Experimental Investigation of the Macrostructure of Textiles
for Surgical Clothes and Medical Drapes ……………………………………… 103
8.1 Introduction …………………………………………………………………………… 103
8.2 Thermophysiological Comfort in an Operating Room …………… 104
8.2.1 Surgeons …………………………………………………………………….. 104
8.2.2 Anesthesiologists and Nurses …………………………………….. 107
8.2.3 Patient ………………………………………………………………………… 107
8.3 Properties of Single Woven Structures for Surgical Clothes
and Drapes …………………………………………………………………………….. 108
8.4 Experimental Assessment of the Air Permeability
of a Single Layer …………………………………………………………………….. 110
8.5 Experimental Assessment of the Air Permeability
of Multilayer Systems …………………………………………………………….. 113
8.5.1 Theoretical Model of Clayton……………………………………… 114
8.5.2 Air Permeability of a System of Two Identical Layers ………114
8.5.3 Air Permeability of a System of Two Different Layers ………116
8.5.4 Air Permeability of a System of Three Identical
Layers ……………………………………………………………………… 116
8.5.5 Regression Models for the Air Permeability of
Systems of Layers ……………………………………………………….. 118
8.5.5.1 Regression Models for the Air Permeability
of a System of Identical Layers ……………………… 118
8.5.5.2 Regression Models for the Air Permeability
of a System of Different Layers …………………….. 119
8.6 Theoretical Models for the Air Permeability of Systems
of Layers ………………………………………………………………………………. 119
8.6.1 Theoretical Model for the Air Permeability
of a System of Identical Layers ………………………………… 119
8.6.2 Theoretical Model for the Air Permeability
of a System of Different Layers ……………………………….. 121
8.7 Experimental Assessment of the Moisture Transport …………… 121
8.7.1 Effect of Fabric Weight …………………………………………….. 123
8.7.2 Effect of Thickness ………………………………………………….. 124
8.7.3 Effect of Areal Porosity ……………………………………………. 126
8.8 Summary ……………………………………………………………………………… 126
9. Experimental Investigation of the Macrostructure of Upholstery
Textiles ……………………………………………………………………………………………. 129
9.1 State of the Art of the Problem ……………………………………………… 129
9.2 Experimental Assessment of the Air Permeability ……………….. 133
9.3 Experimental Assessment of the Heat Transfer ……………………. 138
9.4 Summary ……………………………………………………………………………… 140
10. Experimental Investigation of the Macrostructure of Textiles
for Packing ……………………………………………………………………………………… 141
10.1 State of the Art of the Problem ……………………………………………… 141
10.2 Properties of the Macrostructures ………………………………………… 143
10.3 Experimental Assessment of the Porosity …………………………….. 144
10.4 Experimental Assessment of the Air Permeability of a
Single Layer ………………………………………………………………………….. 148
10.5 Experimental Assessment of the Air Permeability of
Double-Layered Systems ………………………………………………………. 154
10.6 Theoretical Assessment of the Air Permeability of
Double-Layered Systems …………………………………………………..155
10.7 Summary ……………………………………………………………………………… 157
11. Experimental Investigation of Textile Macrostructures in the
Indoor Environment ……………………………………………………………………….. 159
11.1 Introduction …………………………………………………………………………. 159
11.2 Materials in Contact with the Air in the Indoor Environment …… 161
11.2.1 Wood and Wood-Based Materials …………………………… 163
11.2.2 Textiles ……………………………………………………………………. 163
11.2.3 Paper and Paper-Based Materials ……………………………. 164
11.2.4 Gypsum and Gypsum Boards …………………………………. 164
11.2.5 Concrete and Ceramics……………………………………………. 164
11.2.6 Other Materials ……………………………………………………….. 164
11.3 Distribution of Moisture Buffering Materials in Real
Enclosures: Offices and Hotel Rooms …………………………………… 165
11.4 Interaction of Textiles with Water Vapor Indoors …………………. 170
11.5 Sorption Isotherms ………………………………………………………………. 172
11.6 Summary ……………………………………………………………………………… 174
Section III Mathematical Modeling and
Numerical Study of the Properties
of Woven Structures with Respect
to Thermophysiological Comfort
12. Mathematical Modeling and Numerical Simulation of
Air Permeability and Heat Transfer through Woven
Macrostructures: State of the Art …………………………………………………… 177
12.1 Introduction …………………………………………………………………………. 177
12.2 Air Permeability Modeling …………………………………………………… 178
12.3 Heat Transfer Modeling ……………………………………………………….. 182
12.4 Summary ……………………………………………………………………………… 184
13. Simulation of Air Permeability by Using
Hagen–Poiseuille Law …………………………………………………………….. 185
13.1 Applicability of the Hagen–Poiseuille Law …………………………… 186
13.2 Mathematical Model for Calculation of Air Permeability ……………186
13.2.1 Calculation of the Number of Voids np in the
Woven Macrostructure …………………………………………. 187
13.2.2 Calculation of the Diameter of the Threads…………… 187
13.2.3 Determination of the Pore Size ……………………………… 187
13.2.4 Calculation of the Pore Area and Pore Perimeter ….. 188
13.2.5 Determination of the Porosity of the
Macrostructure ……………………………………………………… 188
13.2.6 Calculation of the Thickness …………………………………. 189
13.2.7 Calculation of the Hydraulic Diameter of the Void …….189
13.2.8 Determination of the Mean Velocity ……………………… 189
13.2.9 Calculation of the Hydraulic Area of the Pore ………. 190
13.2.10 Determination of the Air Flow Rate through
the Sample …………………………………………………………….. 190
13.2.11 Determination of the Air Permeability
Coefficient Bp of the Macrostructure……………………… 190
13.3 Theoretical Results ……………………………………………………………….. 191
13.4 Verification of the Model ………………………………………………………. 196
13.5 Numerical Simulation of the Air Permeability of Textiles
for Clothing and Bedding …………………………………………………….. 198
13.5.1 Numerical Procedure and Results …………………………… 198
13.5.2 Verification of the Results ……………………………………….. 199
13.6 Summary ……………………………………………………………………………… 201
14. Mathematical Modeling and Numerical Simulation of the Air
Permeability of Woven Structures by CFD …………………………………….203
14.1 Methods for Modeling of Fluid Flows …………………………………..204
14.2 Mathematical Model ……………………………………………………………..205
14.3 Turbulence Modeling ……………………………………………………………206
14.4 Theoretical Background of the Modeling of Woven
Macrostructures ……………………………………………………………………208
14.4.1 Jet Systems ……………………………………………………………….208
14.4.2 Approximation of a Woven Structure to a Jet
System …………………………………………………………………210
14.5 Numerical Procedure for the Parametric Study ……………………. 211
14.5.1 Computational Domain …………………………………………… 211
14.5.2 Selection of the Woven Macrostructure …………………… 212
14.5.3 Selection of the Jet System ……………………………………….. 213
14.5.4 Selection of a Grid …………………………………………………… 213
14.5.5 Turbulent Model ……………………………………………………… 215
14.5.6 Initial and Boundary Conditions …………………………….. 216
14.5.7 Convergence Conditions …………………………………………. 216
14.5.8 Additional Conditions …………………………………………….. 216
14.5.9 Summary of the Investigated Cases ………………………… 216
14.6 Numerical Results from the Parametric Study ………………………220
14.6.1 Effect of the Number of Jets in the System ……………….220
14.6.2 Effect of the Shape of the Pore Cross Section ……………223
14.6.3 Effect of the Initial Flow Velocity ……………………………..226
14.6.4 Effect of the Numerical Grid ……………………………………228
14.7 Numerical Procedure for the Model Study ……………………………229
14.7.1 Computational Domain ……………………………………………230
14.7.2 Selection of the Woven Macrostructure ……………………230
14.7.3 Selection of the Jet System ………………………………………..230
14.7.4 Selection of a Grid ……………………………………………………230
14.7.5 Turbulent Model ……………………………………………………… 231
14.7.6 Initial and Boundary Conditions …………………………….. 231
14.7.7 Convergence Conditions …………………………………………. 231
14.7.8 Additional Conditions …………………………………………….. 232
14.7.9 Summary of the Investigated Cases ………………………… 232
14.8 Numerical Results from the Model Study ……………………………..233
14.8.1 Effect of the Turbulent Model …………………………………..233
14.8.2 Effect of the Woven Macrostructure ………………………..236
14.8.3 Verification of the Numerical Results for the Air
Permeability from the Model Study ………………………… 239
14.8.4 Modeling of the Porosity of the Mesostructure ……….. 241
14.9 Summary ……………………………………………………………………………… 243
15. Mathematical Modeling and Numerical Simulation of
Heat Transfer through Woven Structures by CFD ………………………… 245
15.1 Mathematical Model …………………………………………………………….. 245
15.2 Numerical Procedure for the Study ……………………………………… 246
15.2.1 Computational Domain …………………………………………… 246
15.2.2 Selection of the Woven Macrostructure …………………… 247
15.2.3 Jet System and Turbulence Modeling ………………………. 247
15.2.4 Selection of a Grid …………………………………………………… 247
15.2.5 Initial and Boundary Conditions …………………………….. 247
15.2.6 Convergence Conditions …………………………………………. 249
15.2.7 Summary of the Investigated Cases ………………………… 249
15.3 Numerical Results …………………………………………………………………250
15.4 Summary ………………………………………………………………………………254
Section IV Mathematical Modeling and Numerical
Study of Thermophysiological
Comfort with a Thermophysiological
Model of the Human Body
16. Thermoregulation of a Clothed Body: Physiological
Peculiarities ………………………………………………………………………………..257
16.1 Thermophysiological Control of the Human Body ……………….. 257
16.1.1 Role of the Hypothalamus ……………………………………….258
16.1.2 Mechanisms of Body’s Thermoregulation ………………. 259
16.1.2.1 Effect of the Environment with High
Air Temperature ………………………………………. 259
16.1.2.2 Effect of the Environment with Low
Air Temperature ………………………………………. 260
16.1.2.3 Body Reactions of Thermal Discomfort ……260
16.2 Thermophysiological Models ……………………………………………….. 261
16.2.1 Hardy’s Classification ……………………………………………… 262
16.2.1.1 Qualitative Models …………………………………… 262
16.2.1.2 Quantitative Models …………………………………263
16.2.2 Classification Based on the Number of Body
Segments ………………………………………………………………….263
16.2.2.1 One-Cylinder Models ……………………………….263
16.2.2.2 Two-Cylinder Models ……………………………….264
16.2.2.3 Multilayered and Multisegment Models …..264
16.2.2.4 New Models ……………………………………………..265
16.3 Gagge’s Thermophysiological Model …………………………………….265
16.3.1 Advantages of the Model …………………………………………265
16.3.2 Description of the Model…………………………………………. 266
16.3.3 Passive System ………………………………………………………… 267
16.3.3.1 Heat Exchange between the Body and
the Environment ……………………………………… 267
16.3.3.2 Heat Exchange between the Core Body
and the Skin …………………………………………….. 270
16.3.4 Control System ………………………………………………………… 271
16.4 Implementation of the Model in FLUENT CFD Software
Package ………………………………………………………………………………… 273
16.5 Summary ……………………………………………………………………………… 273
17. Numerical Study of the Thermophysiological Comfort
of a Clothed Body …………………………………………………………………………… 275
17.1 Specifics of the Study ……………………………………………………………. 275
17.2 Mathematical Model …………………………………………………………….. 276
17.3 Procedure of the Study …………………………………………………………. 278
17.3.1 Local Thermophysical Properties of Textiles
and Clothing …………………………………………………………… 278
17.3.2 Selection of Clothing ……………………………………………….. 279
17.3.3 Selection of Activity ………………………………………………… 279
17.3.4 Parameters of the Indoor Environment ……………………280
17.3.5 Parameters of the Human Body ………………………………. 281
17.3.6 Summary of the Investigated Cases ………………………… 281
17.4 Summary ……………………………………………………………………………… 281
18. Results from the Numerical Study on the Thermophysiological
Comfort of a Clothed Body ……………………………………………………………..283
18.1 Influence of the Environmental Parameters ………………………….283
18.2 Influence of the Clothing Insulation …………………………………….. 287
18.3 Influence of the Activity ………………………………………………………..290
18.4 Application Analyses of the Numerical Results ……………………. 292
18.4.1 Skin Temperature and Clothing Temperature
Isotherms ………………………………………………………………… 292
18.4.2 Regression Analysis ………………………………………………… 295
18.4.2.1 Influence of the clo Value …………………………. 295
18.4.2.2 Influence of the Activity …………………………… 297
18.4.2.3 Application of the Regression Models
and Their Verification ………………………………. 297
18.5 Summary ………………………………………………………………………………300
References …………………………………………………………………………………………….. 301
Index ……………………………………………………………………………………………………… 319

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