Multiphase movement

In the upper unsaturated zone (above the capillary fringe), multiphase movement and transformation are typical. Vapor-phase gasoline becomes more important gasoline adsorption by soil, dissolution in pore water, and free product in the pore space can also be significant. 

Similar to gasoline, the properties of DNAPLs such as immiscibility with water, volatility, and solubility of some of its components cause the presence of multiphase (pure product, solute, gas, and adsorbate) products and movement that is typical of the phenomena associated with DNAPL release. The theory associated with the interaction of gasoline with soil is applicable to DNAPLs. However,... 

Fig. 11.1 Schematic representation of NAPL movement from land surface to the water table region, (a) LNAPL movement, and (b) DNAPL movement (after Abriola and Pinder 1985). Reproduced by permission of American Geophysical Union. Abriola LM, Pinder GF (1985) A multiphase approach to the modelling of porous media contamination by organic compounds. Water Resour Res 21 11-18. Copyright 1985 American Geophysical Union...

A variety of factors affect the horizontal and vertical migration of PAHs, including contaminant volume and viscosity, temperature, land contour, plant cover, and soil composition (Morgan Watkinson, 1989)- Vertical movement occurs as a multiphase flow that will be controlled by soil chemistry and structure, pore size, and water content. For example, non-reactive small molecules (i.e., not PAHs) penetrate very rapidly through dry soils and migration is faster in clays than in loams due to the increased porosity of the clays. Once intercalated, however, sorbed PAHs are essentially immobilized. Mobility of oily hydrophobic substances can potentially be enhanced by the biosurfactant-production capability of bacteria (Zajic et al., 1974) but clear demonstrations of this effect are rare. This is discussed below in more detail (see Section 5 5). 

Fraser Russell I d like to say a bit about multiphase fluid mechanics. If one is concerned with design and, as Gary said, focusing on the macroscale (Fig. 1), one needs a lot more information about the creation and/or movement... 

Two things occur during in situ combustion underground (a) oxidation of some of the substances, and (b) thermal treatment of the oil-bearing bed by heat released during this oxidation process. The movement of substances in the zone that has been heated and ahead of it can be described by using equations for filtration of multiphase fluids. 

There is a growing interest in the development of multiphase ceramics. Both the processing and the use of each of the materials described above may involve a solid-state reaction and the movement of a phase boundary. There are, of course, many other situations in which solid-state... 

Electroosmotic multiphase flows. Multiphase flows driven by electrical force have attracted increasing levels of interest and potential applications in biomedical techniques. Such flows include unchanging-interface suspension flows, such as blood cell or DNA molecule suspension, and multiphase interface flows, such droplet movement in a microchannel driven by an electric held. No good solutions by conventional CED have been found for such flows. Since much progress has been made in solving the multiphase interface problems by LBM, the LPBM is very promising to provide full simulations and analysis of electroosmotic multiphase flows. 

A. Kibar, R. Ozbay, M. A. Sarshar, Y. T. Kang, and C.-H. Choi, Air bubble movement over and under hydrophobic surfaces in water, in Proceedings of the 8th International Conference on Multiphase Flow, Jeju, Korea, (May 2013). 

---