Book contents
- Frontmatter
- Contents
- Preface
- Notation
- 1 Introduction
- 2 Mesoscale description of polydisperse systems
- 3 Quadrature-based moment methods
- 4 The generalized population-balance equation
- 5 Mesoscale models for physical and chemical processes
- 6 Hard-sphere collision models
- 7 Solution methods for homogeneous systems
- 8 Moment methods for inhomogeneous systems
- Appendix A Moment-inversion algorithms
- Appendix B Kinetics-based finite-volume methods
- Appendix C Moment methods with hyperbolic equations
- Appendix D The direct quadrature method of moments fully conservative
- References
- Index
5 - Mesoscale models for physical and chemical processes
Published online by Cambridge University Press: 05 March 2013
- Frontmatter
- Contents
- Preface
- Notation
- 1 Introduction
- 2 Mesoscale description of polydisperse systems
- 3 Quadrature-based moment methods
- 4 The generalized population-balance equation
- 5 Mesoscale models for physical and chemical processes
- 6 Hard-sphere collision models
- 7 Solution methods for homogeneous systems
- 8 Moment methods for inhomogeneous systems
- Appendix A Moment-inversion algorithms
- Appendix B Kinetics-based finite-volume methods
- Appendix C Moment methods with hyperbolic equations
- Appendix D The direct quadrature method of moments fully conservative
- References
- Index
Summary
This chapter illustrates and discusses some of the most widely used mesoscale models for describing particulate processes. The reader should keep in mind that the chapter is not a comprehensive discussion of all the possible mesoscale models, but is simply a collection of some example models, used in this context to highlight the major issues typically encountered in the simulation of multiphase systems. Although some of the models illustrated in the next sections have general validity, they typically assume slightly different forms when applied to the simulation of solid–liquid systems (e.g. crystallization and precipitation processes), solid–gas systems (e.g. fluidized suspensions, aerosol reactors), liquid–liquid systems (e.g. emulsions), gas–liquid systems (e.g. bubble columns and gas–liquid stirred tanks), and liquid–gas systems (e.g. evaporating and non-evaporating sprays). In what follows we will often refer to the elements of the disperse phase as “particles” to indicate both solid particles (such as crystals, solid amorphous particles, and solid aggregates) and fluid particles (such as droplets and bubbles). The remainder of the chapter is organized as follows. After providing an overview of the philosophy behind the development of mesoscale models in Section 5.1, specific examples of phase-and real-space advection processes (and the consequent diffusion processes) are discussed in Sections 5.2–5.5. Subsequently, phase-space point (discontinuous) processes are presented in Sections 5.6–5.8. For each of these processes, the corresponding functional form of the mesoscale model appearing in the final GPBE is derived and discussed.
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- Publisher: Cambridge University PressPrint publication year: 2013