High multiphase flows

Chung PM-Y, Kawaji M (2004) The effect of channel diameter on adiabatic two-phase flow characteristics in micro-channels. Int J Multiphase Flow 30 735-761 Colgan E (2005) A practical implementation of silicon microchannel coolers for high power chips. 

Optical systems can be used in multiphase flows at a very low volume fraction of the dispersed phase. Through a refractory index matching of hquid-liquid or liquid-solid systems, it is also possible to measure at high void fractions. However, it is not possible to obtain complete refractory index matching since the molecules at the phase boundary have different optical properties than the molecules in the bulk. Consequently, it is possible to measure at a higher fraction of the dispersed phase with larger drops and particles because of the lower surface area per volume fluid. 

The low density of gases makes it more difficult to keep the bubbles dispersed. The bubbles will move to the low-pressure areas, that is, behind the impellers, in the trailing vortices close to the impeller, behind the baffles, and at the inner side after a bend. The bubbles will coalesce in these areas with high gas holdup. It is very difficult to design reactors without low-pressure regions where the low-density fluid will accumulate. One such reactor is the monolith reactor for multiphase flow [32, 33]. 

Because gasoline is composed of some highly volatile and soluble hydrocarbon fractions, its components can move in the subsurface in three states vapor, solute, and liquid. The form of its components in the soil are vapor, solute, free product, and adsorbate. The multiphase flow of... 

Celata, G. P., 1991, A Review of Recent Experiments and Predictive Aspects of Burnout at Very High Fluxes, Proc. Int. Conf. on Multiphase Flow, Tsukuba, Japan, September. (5)... 

Jens, W. H., and P. A. Lottes, 1951, Analysis of Heat Transfer, Burnout, Pressure Drop, and Density Data for High Pressure Water, USAEC Rep. ANL-4627, Argonne Natl. Lab., Argonne, IL. (4) Jepson, W. P., and R. E. Taylor, 1993, Slug Flow and Its Transitions in Large-Diameter Horizontal Pipes, Int. J. Multiphase Flow 19(3) 410420. (3)... 

Although several different system configurations have been simulated, the focus of this paper will be on the unsteady, compressible, multiphase flow in an axisymmetric ramjet combustor. After a brief discussion of the details of the geometry and the numerical model in the next section, a series of numerical simulations in which the physical complexity of the problem solved has been systematically increased are presented. For each case, the significance of the results for the combustion of high-energy fuels is elucidated. Finally, the overall accomplishments and the potential impact of the research for the simulation of other advanced chemical propulsion systems are discussed. 

One of the important characteristics of gas-solid multiphase flows is concerned with the electrostatic effect. Particles can be charged by surface contact in a collision, by corona charging and scattering in an ionized gas, by thermionic emission in a high-temperature environment, and by other charging mechanisms such as colloidal propulsion... 

Savage, S. B. (1983). Granular Flows at High Shear Rates. In Theory of Dispersed Multiphase Flow. Ed. R. E. Meyer. New York Academic Press. 

To further stabilize multiphase flow, the liquid-liquid interface can be created at the boundary formed at a constricted opening [427]. Moreover, guide structures (5 pm high) were fabricated in a microchannel (20 pm deep) to stabilize a three-phase flow, as shown in Figure 3.16. These structures were etched on quartz using... 

With regard to multiphase flow measurement, two of the most commonly used flow meter devices in industry are the Coriolis flow meter and electromagnetic flow meter. The Coriolis flow meter is widely used owing to its high accuracy (Tavoularis, 2005) but it assumes... 

Especially for multiphase systems flow visualization (Wen-Jei Yang, 1989 Merzkirch, 1987) can provide valuable initial information on the prevailing flow patterns and should at least always be considered as a first step. Of course, in applications that involve extreme conditions such as high temperature and/or pressure it is very difficult if not impossible to apply flow visualization and other techniques should be considered. Here the use of cold flow models which permit visual observation might be considered as an alternative as an important first step to obtain (qualitative) information on the flow regime and associated flow pattern. Of course, multiphase flows exist such as dense gas-solid flows that do not permit visual observation and in such cases the application of idealized flow geometries should be considered. A well-known example in this respect is the application of so-called 2D gas fluidized beds to study gas bubble behavior (Rowe, 1971). 

M. Aritomi, T. Miyata, M. Horiguchi, and S. Sudi. Thermohydraulics of boiling two-phase flow in high conversion light water reactors (thermohydraulics at low velocities) . International Journal of Multiphase Flow, 19, l,pp. 51-63 (1993). 

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