What Is Fluid Turbulence? (eBook)

Turbulent oscillation and convection

Gert Naue (Autor)

eBook Download: PDF

2018 | 1. Auflage
420 Seiten
TWENTYSIX (Verlag)
978-3-7407-0155-0 (ISBN)

Infos

This book presents an innovative wave structure theory of turbulence. The most important advancement is the provision of turbulence parameters of the optimal self-organization of turbulence from theoretical investigations via information entropy assessments. The new theoretical results are in very good agreement with the experimentally confirmed results of turbulent convection velocity fields at free and forced turbulence. In connection with the logarithmic wall law, it is shown that there is no viscous sublayer. The formulation of the oscillation problem of turbulence and the solution of boundary value tasks with coordinate systems adapted to the specific task are provided for many technically significant turbulent flows, including smooth and rough pipe flow, confusor and diffuser flow, swirl flow, stirrer flow, inlet flow, intermittency, wake flow and free jets. An epistemological component of the innovation is the representation of turbulence by con-travariant vector fields which are characterized by the stability of the turbulence structures at changed structural density. The turbulence structures act as active momentum transmitters of refracted monopoles, dipoles, tripoles and quadrupoles in the flow field. The dissipation mechanism with regard to the processes in turbulence structures is, for the first time, qualita-tively and quantitatively described. The transition from the contravariant turbulence velocity field to the covariant convection velocity field induce refraction and entanglement. The principles of turbulence act as fractal principle, reflection principle, entanglement principle, refractive principle and convolution principle. The wave structure theory of turbulence provides an arraying tool for further investigations into numerous open problems.

Gert Naue was born July 21st, 1934 in Leipzig, Germany. Following his Abitur (general qualification for university entrance) in 1953, he studied aerodynamics at the Technical University of Dresden and obtained an engineering diploma in 1958 and a doctorate in 1962. His habilitation in 1967 was supervised by Prof. Werner Albring. From 1961 to 1965 Gerd Naue held the position of Head of the Research Department for Thermodynamics at the Research and Testing Institute for Fluid Kinetic Machines in Dresden and the Scientific and Technical Center for Power Plants in Pirna. From 1965 to 1967 he was Lecturer and then from 1967 to 1992 Full Professor of Fluid Mechanics at the Technical University of Merseburg. In 1992 he became a managing partner at a privately held engineering service provider in Dresden. Since retirement in 1999 he has been engaged in freelance assignments in the fields of process engineering, fluid mechanics and thermodynamics.

Inhalt

Title Page 2
Copyright 3
Preface 4
Introduction 7
Table of Contents 11
1. Laminarity, turbulence and structures 14
2. Turbulence convection models 24
2.1 Navier-Stokes equation 25
2.2 Turbulence models 26
2.3 Trajectory equation 27
3. Coherences and differences of convection model and oscillation model 32
3.1 Velocity terms and definitions 32
3.2 Wave propagation . 33
3.3 Connectivity of Navier-Stokes equation and oscillation equation 37
4. Optimal self-organization of turbulence 40
4.1 Space-time-averaging of the fluctuation motion 40
4.2 Information entropy as an assessment measure in turbulence processes 43
4.3 Phase differences and phase entanglement 46
4.4 Turbulence velocity 47
4.5 Critical quantities 50
4.6 Impact laws of turbulent structures 53
4.7 Pressure loss in case of forced turbulence 56
4.8 Self-similar dimension of dissipation structures 69
4.9 Free jet spreading 73
4.10 Free jet buckling and maximal height in cross winds 77
4.11 Turbulence structures 82
4.11.1 Turbulence structures in wave packets 82
4.11.2 Turbulence structures as singularities 84
4.11.3 Turbulence structures as modified singularities 86
4.11.4 Similarity behavior of modified polar structures 90
4.11.5 Coexistence of polar structures 94
5. Oscillation model of turbulence 98
5.1 Oscillation shape of turbulence 98
5.2 Amplitude shape of turbulence 102
5.3 Polar shape of turbulence 104
5.4 Phase shape of turbulence 106
5.5 Coexistence shape of turbulence 110
5.6 Performance and energy shapes of turbulence 114
5.7 Convolution shapes of turbulence 123
5.7.1 Continuous convolution 123
5.7.2 Discrete convolution with mapping of information entropy 127
5.8 Geometric entanglement shape of turbulence 128
6. Principles of turbulence 132
6.1 Fractal principle 133
6.2 Reflection principle 136
6.3 Entanglement principle 137
6.4 Principle of refraction 138
6.5 Convolution principle 142
7. Special forced-turbulent flows 144
7.1 Smooth pipe flow 144
7.2 Rough pipe flow 165
7.3 Swirl promoter flow 175
7.4 Diffusor and confusor flows 185
7.5 Solitons and soliton waves in channel flows 191
7.6 Intermittency 200
7.7 Inlet flow in the pipe 215
7.8 Ring flow 225
7.8.1 Turbulent ring flow 226
7.8.2 Turbulent stirrer flow 235
7.9 Pressure changes in axial flows 237
7.9.1 Separation-free axial flows 237
7.9.2 Axial flows with flow separations 238
7.10 Dissipation and turbulence structure 242
7.11 Summary 251
8. Free-turbulent flows 252
8.1 Interlayer flow 253
8.2 Wake flow 260
8.2.1 Planar wake flow 262
8.2.2 Round wake flow 282
8.2.3 Generalization of wake flow effects 291
8.3 Free jet flow 293
8.3.1 Geometric coherences 294
8.3.2 Oscillation model of the free jet 302
8.3.3 Mass- and momentum flows along the free jet axis 314
8.3.4 Free jets of continuously miscible fluids 328
8.3.5 Range of round straight free jets 334
8.3.6 Round free jet in crosswind 339
9. Discussion of the ‘universal’ laws of the wall of forced turbulence 344
9.1 ‘Universal’ law and viscous sublayer in the smooth pipe 344
9.1.1 Momentum limitation in the areas closest to the wall 347
9.1.2 Refraction in the range close to the wall at Re á 3ö49 353
9.1.3 Transformation of the velocity distributions into the metric space 355
9.1.4 Motion variety at forced turbulence 359
9.2 Universal’ law of the wall in the rough pipe 363
9.2.1 Wall law in the constancy range of the mean velocity 366
9.2.2 Additional velocities due to radial and axial transverse waves 368
10. Open problems 374
10.1 Flow separation 374
10.2 Stagnation flows / Impact jets 375
10.3 Energy induced free turbulence 375
10.4 Wall boundary layers 376
10.5 Flows in non-circular channels 377
10.6 Two-phase flows 377
10.7 Detection of turbulence structures (quadrupoles, dipoles) 378
10.8 Particle flows in the cosmos 378
10.9 Compactness of turbulence structures 379
11. Directories 382
11.1 Bibliography 382
11.2 Index 384
12. Appendix 394
12.1 Transformation of Cartesian coordinates into curvilinear coordinates 395
12.2 Operations applied to physical components and / or covariant vector fields, respectively 397
12.3 Operations, applied to contravariant vector fields 399
12.4 Distributions of convection and turbulence velocity in the smooth pipe as a function of the Reynolds number, see Explanations p. 343 re. Fig. 9-9 400
12.5 Convection velocity distributions in the rough pipe at different sand roughness, see Explanatory notes pp. 359/360 re. Figs. 9-21 and 9-22 416

Produkt-Details

• Erscheint lt. Verlag: 1.8.2018
• Sprache: englisch
• Themenwelt: Naturwissenschaften ► Physik / Astronomie
• ISBN-10: 3-7407-0155-2 / 3740701552
• ISBN-13: 978-3-7407-0155-0 / 9783740701550