Book contents
- Frontmatter
- Contents
- Preface
- Frequently Used Notation
- TWO-PHASE FLOW, BOILING AND CONDENSATION IN CONVENTIONAL AND MINIATURE SYSTEMS
- PART ONE TWO-PHASE FLOW
- 1 Thermodynamic and Single-Phase Flow Fundamentals
- 2 Gas–Liquid Interfacial Phenomena
- 3 Two-Phase Mixtures, Fluid Dispersions, and Liquid Films
- 4 Two-Phase Flow Regimes – I
- 5 Two-Phase Flow Modeling
- 6 The Drift Flux Model and Void–Quality Relations
- 7 Two-Phase Flow Regimes – II
- 8 Pressure Drop in Two-Phase Flow
- 9 Countercurrent Flow Limitation
- 10 Two-Phase Flow in Small Flow Passages
- PART TWO BOILING AND CONDENSATION
- APPENDIX A Thermodynamic Properties of Saturated Water and Steam
- APPENDIX B Transport Properties of Saturated Water and Steam
- APPENDIX C Thermodynamic Properties of Saturated Liquid and Vapor for Selected Refrigerants
- APPENDIX D Properties of Selected Ideal Gases at 1 Atmosphere
- APPENDIX E Binary Diffusion Coefficients of Selected Gases in Air at 1 Atmosphere
- APPENDIX F Henry's Constant of Dilute Aqueous Solutions of Selected Substances at Moderate Pressures
- APPENDIX G Diffusion Coefficients of Selected Substances in Water at Infinite Dilution at 25°C
- APPENDIX H Lennard–Jones Potential Model Constants for Selected Molecules
- APPENDIX I Collision Integrates for the Lennard–Jones Potential Model
- APPENDIX J Physical Constants
- APPENDIX K Unit Conversions
- References
- Index
5 - Two-Phase Flow Modeling
- Frontmatter
- Contents
- Preface
- Frequently Used Notation
- TWO-PHASE FLOW, BOILING AND CONDENSATION IN CONVENTIONAL AND MINIATURE SYSTEMS
- PART ONE TWO-PHASE FLOW
- 1 Thermodynamic and Single-Phase Flow Fundamentals
- 2 Gas–Liquid Interfacial Phenomena
- 3 Two-Phase Mixtures, Fluid Dispersions, and Liquid Films
- 4 Two-Phase Flow Regimes – I
- 5 Two-Phase Flow Modeling
- 6 The Drift Flux Model and Void–Quality Relations
- 7 Two-Phase Flow Regimes – II
- 8 Pressure Drop in Two-Phase Flow
- 9 Countercurrent Flow Limitation
- 10 Two-Phase Flow in Small Flow Passages
- PART TWO BOILING AND CONDENSATION
- APPENDIX A Thermodynamic Properties of Saturated Water and Steam
- APPENDIX B Transport Properties of Saturated Water and Steam
- APPENDIX C Thermodynamic Properties of Saturated Liquid and Vapor for Selected Refrigerants
- APPENDIX D Properties of Selected Ideal Gases at 1 Atmosphere
- APPENDIX E Binary Diffusion Coefficients of Selected Gases in Air at 1 Atmosphere
- APPENDIX F Henry's Constant of Dilute Aqueous Solutions of Selected Substances at Moderate Pressures
- APPENDIX G Diffusion Coefficients of Selected Substances in Water at Infinite Dilution at 25°C
- APPENDIX H Lennard–Jones Potential Model Constants for Selected Molecules
- APPENDIX I Collision Integrates for the Lennard–Jones Potential Model
- APPENDIX J Physical Constants
- APPENDIX K Unit Conversions
- References
- Index
Summary
General Remarks
The design and analysis of systems often require the solution of mass, momentum, and energy conservation equations. This is routinely done for single-phase flow systems, where the familiar Navier–Stokes equations are simplified as far as possible and then solved. The situation for two-phase flow systems is more complicated, however. The solution of the rigorous differential conservation equations is impractical, and a set of tractable conservation equations is needed instead. To derive tractable and at the same time reasonably accurate conservation equations, one needs deep physical insight (to make sensible simplifying assumptions) and mathematical skill. Fortunately, the subject has been investigated for decades, and at this time we have well-tested sets of tractable two-phase conservation equations that have been shown to do well in comparison with experimental data.
Generally speaking, conservation equations can be formulated and solved for multiphase flows in two different ways. In one approach, every phase is treated as a continuum, and all the conservation equations are presented in the Eulerian frame (i.e., a frame that is stationary with respect to the laboratory). This approach is quite general and can be applied to all flow configurations. In another approach, which is applicable when one of the phases is dispersed while the other phase is contiguous (e.g., in dispersed-droplet flow), the contiguous phase (the gas phase in the dispersed-droplet flow example) is treated as a continuum and its conservation equations are formulated and solved in the Eulerian frame.
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- Two-Phase Flow, Boiling, and CondensationIn Conventional and Miniature Systems, pp. 137 - 172Publisher: Cambridge University PressPrint publication year: 2007
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