Index
Note: ‘Page numbers followed by “f” indicate figures and “t” indicate tables.’
Active devices, 44
Aerodynamic drag
CFD calculations, 137–138
CFD modelling, 130–131
Davis equation, 129–130
deceleration/velocity curve, 134f
determination, 133–138
drag reduction methods, 146–149
full-scale coasting tests, 133–135
low-speed hauling test, 134
predictive formulae, 139–141
reduction and optimisation, 133
Reynolds' number, 137
specification of, 129–133
Air quality, 307
Alleviation, tunnel, 283–291
adjustment of train speed, 283–284
cross-passages, 287
modification of tunnel area, 283
Ambient airflows, 116
Atmospheric wind, 28–33
Aural pressure comfort, 272–282
Ballast flight beneath trains
AeroTRAIN, 181–182
authorisation, 196–199
ballast in motion, 192–195
ballast movement initiation, 188–190
ejection, 195–196
incipient motion analysis, 190–192
infrastructure operation, 196–199
safe behavioural boundary, 192
stone impact, 195–196
Characteristic wind curves, 230–231
calculated values, 258t
train parameters, 258t
Chinese hat method, 246–248
Codified methodologies, 15
Collation
pressure loads, 155–162
Compressible flow models, 268–270
constant density, finite speed-of-sound model, 269
constant entropy with friction model, 268
constant entropy without friction model, 269
incompressible flow model, 269
variable entropy model, 268
Computational techniques
analytical methods, 53–55
computational fluid dynamics (CFD), 54
detached eddy simulation (DES), 54
direct numerical simulation, 62–65
cell size, 62–63
one-dimensional discretisation, 68f
time step limits, 62–63
Laplace's equation, 55–56
large eddy simulation (LES), 54
Lattice Boltzmann method (LBM), 54–55
optimisation methods, 66–71
design approach, 67
multiobjective optimisation, 71
rationale, 66–67
surrogate model, 68–71
representation of turbulence, 58–59
Reynolds stress models, 61–62
turbulence viscosity models, 59–61
unsteady Reynolds-averaged Navier–Stokes, 62
Conservation of energy, 19
Conservation of mass, 19
Conservation of momentum, 19
Constant density model, 269
Constant entropy with friction model, 268
Constant entropy without friction model, 269
Cross-passages, 287
stability, 230–231
Data acquisition, 35–37
Data analysis, 37
Davis equation, 129–130
Deceleration/velocity curve, 134f
Dewirement analysis, 226–227
Dimensional analysis, 17–18
Direct numerical simulation, 62–65
cell size, 62–63
one-dimensional discretisation, 68f
time step limits, 62–63
Drag, 4–9
Drag reduction methods, 146–149
Energy, 19
Equations of motion, 21–23
Finite speed-of-sound model, 269
Flow around trains
boundary layer region, 83–88
flow regions, 73–75
model-scale experiments, 73
nose peak-to-peak pressure coefficients, 82t
skin friction coefficients, 96t
train side and roof, 83–88
Flow regions, 73–75
Fluid mechanics concepts
atmospheric wind near the ground, 28–33
boundary layers, 20
conservation of energy, 19
conservation of mass, 19
conservation of momentum, 19
dimensional analysis, 17–18
energy, 19
equations of motion, 21–23
forces, 19
frames of reference, 18–19
free flows, 20
Gumbel distribution, 31f
Navier–Stokes equations, 22–23
potential flow, 25–26
Reynolds stress, 23
second viscosity, 22
separation, 20–21
thunderstorms, 33
tornadoes, 33
turbulence, 20
turbulent flows, 26–28
velocity intensity, 32f
wakes, 20–21
Force and moment coefficients
characteristics, 238–239
Force measurement, 50
Frames of reference, 18–19
Free flows, 20
Friction coefficients, 183
Full-scale coasting tests, 133–135
Full-scale testing
data acquisition, 35–37
data analysis, 37
instruments, 35–37
Gumbel distribution, 31f
Gust wind speed, 246
High winds, train overturning
aerodynamic characteristics, 231–244
CFD calculations, 237–238
crosswind stability, 230–231
force and moment coefficients
characteristics, 238–239
full-scale measurements, 233–234
generic assessment methodology, 231f
issues, 229–230
physical model tests, 234–237
train authorisation, 259
vehicle system models, 251–253
wind simulations, 245–249
Chinese hat method, 246–248
extreme gust, 246–248
gust wind speed, 246
small-scale storms, 248–249
wind speeds, 245
wind time series, 248
Horizontal mechanical force, 188
Incompressible flow model, 269
Instability risk
stability data, 174–176
Laplace's equation, 55–56
Large-scale physical models, 183
Laser Doppler anemometry (LDA), 49
Limit values comparison, 174–176
Low-speed hauling test, 134
Micropressure waves, 123–124
Modelling basics, 267–268
Model-scale experiments, 73
Momentum equations, 22
Multiobjective optimisation, 71
Navier–Stokes equations, 22–23
New forms of transport, 308–309
New materials, 308
Non-carbon-based power systems, 305
Non-streamlined bodies, 20–21
Nose peak-to-peak pressure coefficients, 82t
One-dimensional discretisation, 68f
Overhead current collection system, 202–204
Overhead line equipment (OLE) systems, 201–202
aerodynamic issues, 204–210
essential clearance, 204
intentional contact, 203
Overhead wire
displacements, 204
galloping instabilities, 207–210
self-induced forces, 204
wind effects, 205–207
Pantograph aerodynamics, 9
aerodynamic force optimisation, 217–225
aerodynamic issues, 210–217
CFD modelling, 217
full-scale testing, 215–216
testing, 210–217
Particle image velocimetry (PIV), 49
Pitot-static tube, 47
Pneumatic railway, 3
Potential flow, 25–26
Pressure coefficient data, 185–186
Pressure loads
analytical models, 155
application, 162–164
CFD calculations, 154–155
collation, 155–162
full-scale measurements, 152–153
measuring methods, 152–155
quantifying methods, 152–155
slipstream loads, 151
Technical Standards for Interoperability (TSIs), 152–153
UIC guidance, 155–156
Pressures, 75–80
Pressure transducer system, 51f
Pressure transients calculation, 267–272
Pressure waves, 114
RANS, See Reynolds-averaged Navier-Stokes (RANS)
Reducing energy consumption, 305–306
Representation of turbulence, 58–59
Resilient rail networks, 306–307
representation of turbulence, 58–59
Reynolds stress models, 61–62
turbulence viscosity models, 59–61
unsteady Reynolds-averaged Navier–Stokes, 62
Route overturning risk, 260–262
risk calculation, 261–262
wind probability distributions, 260–261
Second viscosity, 22
Separation, 20–21
Shields parameter, 190
Skin friction coefficients, 96t
Slipstream loads, 151
application, 172–179
computational fluid dynamics, 168
limit values comparison, 174–176
measuring methods, 165–168
nature, 164–165
physical model measurements, 167–168
quantifying methods, 165–168
Slipstream velocity, 11
Small-scale storms, 248–249
assessing micropressure wave generation, 291–292
Streamlined bodies, 20–21
Structural loading, 299
Subjective pressure tests, 273–274
Surrogate model, 68–71
Technical Standards for Interoperability (TSIs), 152–153
Testing techniques
physical model testing, 38–51
active devices, 44
force measurement, 50
Laser Doppler anemometry (LDA), 49
particle image velocimetry (PIV), 49
pressure measurement, 50
pressure transducer system, 51f
Reynolds number, 39
Thunderstorms, 33
Time step limits, 62–63
Tornadoes, 33
Train aerodynamics
aerodynamic issues, 9–12
crosswind effects, 11–12
pantograph aerodynamics, 9
passing trains pressure, 11
train slipstreams, 11
tunnel aerodynamics, 10
Train information
freight locomotives, 318–322
high-speed passenger trains, 311–314
low-speed passenger trains, 316–318
medium-speed passenger trains, 314–316
Train pressure sealing, 287–288
Train pressure transients, 11
Train slipstreams, 11
TRANSAERO project, 15
Transient Railway Aerodynamic Investigation Rig (TRAIN Rig), 45–46
Transport carbon-based energy consumption, 305
Trumpet-shaped portals, 117
alleviation, 283–291
adjustment of train speed, 283–284
cross-passages, 287
methods, 283
modification of tunnel area, 283
aural pressure comfort, 272–282
compressible flow models, 268–270
constant density, finite speed-of-sound model, 269
constant entropy with friction model, 268
constant entropy without friction model, 269
incompressible flow model, 269
variable entropy, 268
empirical inputs, 270–272
health limits, 272–282
long tunnel, 300–302
medical safety limit, 281–282
methods of solution, 270
modelling basics, 267–268
physiological effects, 272–273
pressure transients calculation, 267–272
structural loading, 299
subjective pressure tests, 273–274
Tunnels
air movements, 111
ambient airflows, 116
blockage ratio, 116
installed tunnel equipment, 122
micropressure waves, 123–124
pressure emissions, 111
pressure waves, 114
solid angle, 124
trumpet-shaped portals, 117
unattenuated pressure changes, 117
Turbulence, 20
viscosity models, 59–61
Turbulent flows, 26–28
Unsteady Reynolds-averaged Navier–Stokes, 62
Variable entropy model, 268
Vehicle system models, 251–253
Very high-speed transport, 309–310
Virtual coupling, 308–309
Wakes, 20–21
Wind-induced galloping oscillations, 9
Wind probability distributions, 260–261
Wind simulations, 245–249
Chinese hat method, 246–248
extreme gust, 246–248
gust wind speed, 246
small-scale storms, 248–249
wind speeds, 245
wind time series, 248
Wind speeds, 245
Wind time series, 248
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