Surface Forces and Their Application to Particle Deposition and Resuspension
The purpose of this chapter is to provide an introduction to surface forces and to highlight their role in the context of particle deposition and resuspension. For that purpose, surface forces are first presented with a specific emphasis on the DLVO theor
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Abstract The purpose of this chapter is to provide an introduction to surface forces and to highlight their role in the context of particle deposition and resuspension. For that purpose, surface forces are first presented with a specific emphasis on the DLVO theory, which combines both van der Waals and electrostatic double-layer contributions within a single theory. The limitations and possible extensions of the DLVO theory are also briefly outlined, especially the role played by surface properties (such as surface roughness or surface charge heterogeneities). Then, the impact of such surface forces on particle deposition and resuspension is analysed with a brief review of some experimental results. Besides, the development of modelling approaches including the coupling and resulting effects of these various phenomena/mechanisms (with very different spatial- and time-scales) is illustrated with a thorough description of a one-point PDF modelling approach together with corresponding numerical results.
1 Introduction As emphasised in the general Introduction by Jean-Pierre Minier, particle deposition results from the interplay between hydrodynamic transport and physico-chemical interactions. Whereas other chapters are mostly focussed on the hydrodynamic interactions (i.e. how particle-fluid interactions affect the motion of suspended materials) either from an experimental or a theoretical/numerical point of view, the present chapter is mostly concerned with physico-chemical interactions that occur between surfaces (i.e. upon particle-surface or particle-particle encounters). In particular, the various examples of systems affected by particle deposition presented in the general introduction have revealed the intricate coupling between hydrodynamic interactions
C. Henry (B) Institute of Fluid Flow Machinery, Polish Academy of Science, ul. Fiszera 14, 80-231 Gda´nsk, Poland e-mail: [email protected] © CISM International Centre for Mechanical Sciences 2017 J.-P. Minier and J. Pozorski (eds.), Particles in Wall-Bounded Turbulent Flows: Deposition, Re-Suspension and Agglomeration, CISM International Centre for Mechanical Sciences 571, DOI 10.1007/978-3-319-41567-3_5
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and physico-chemical forces between surfaces. Therefore, the aim of the present chapter is to provide insights into the following questions: (1) What are the main forces at play in the physico-chemical interactions between surfaces? What are their main characteristics? (2) What are the effects of these physico-chemical interactions on particle deposition and particle resuspension? (3) How can modelling approaches be designed to capture this intricate coupling between hydrodynamics and interface forces? For that purpose, the DLVO theory is first presented in Sect. 2, where the two main contributions of DLVO forces are detailed (i.e. van der Waals forces in Sect. 2.1 and electrostatic double-layer interactions in Sect. 2.2) and the resulting DLVO forces are described in Sect. 2.3. The limitations of the DLVO theory together
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