Simulation of drainage

If the adsorbed surfactant is unable to completely prevent lateral motion at the film surfaces, it is still possible to obtain an analytical solution for the rate of drainage of a film of uniform thickness. The most recent of these analyses (Singh et al., 1996), which employs an improved boundary condition on the surface velocity at the film perimeter based on results of numerical simulations of drainage of nonuniform films, yields the following expression for the ratio V ... 

The left side of the equation has the form of a modified Bessel function of zero order. After defining suitable dimensionless variables, this equation can be solved to obtain Equation 7.81 (Singh et al., 1996). The boundary conditions employed in the solution are that 1/ = 0 for r = 0 and dt//dr = 0 at the film periphery r = R. The latter condition is based on the results of numerical simulation of drainage with nonuniform thickness. It was found that dWdr was zero at the barrier ring (i.e., the point of minimum thickness between the central part of the film and the surrounding meniscus). 

M. Hilpert and C. T. Miller, Pore-morphology-based simulation of drainage in totally wetting porous media , Water Resour., 24,243 (2001). 

Simulations of drainage in the Finney pack were conducted with the algorithms described above for the different levels of W connectivity. The simulations began with the pore space occupied entirely by W phase and were carried out to irreducible W phase saturation that is, the capillary pressure was increased in increments until no fiirther movement of the meniscus was possible. When W is assumed to be completely connected, the meniscus moves indefinitely at grain contacts with no gap between the spheres, but the area and volume of the pendular rings at these contacts quickly become negligible. 

The conservation experiments required books uniformly damaged by flood water. A simulated flood, drainage, and book-freezing sequence was developed so that it would be applied to these two groups of books resulting in a minimal variation in damage. The composition of the uncoated and the coated paper was held basically constant in these studies. Future extension of this research effort should consider varying... 

Simulation of the flood to determine its effect on the quality of paper in books as well as the structure of the book itself is reproducible. The simulation of the drainage conditions is also reproducible for books manufactured with the same materials. There is evidence that the rate of water loss from the books is associated with the type of paper in the text of the book. Evidence exists that comparable amounts of water are... 

Recently Joye et at. [74] have reported a numerical simulation of instability causing asymmetric drainage in foam films. The results obtained confirmed the rapid increase in drainage rate. 

Testing for applications in belt presses is most commonly done by flocculation in beakers and visual observation of the size and strength of the formed floes. The conditioned sluny can be poured into a filter for a gravity drainage test. These tests can be useful for an e3q>erienced person to evaluate if a sluny can be used in belt presses and to optimize an existing belt press. However, the simulation of the final cake dryness is not... 

The maximum rate of entry into surface water (2 m average depth) via runoff is 0,019 lb PBO per acre X 10 acres of drainage = 0,19 lb PBO per acre (or 0 084 kg ha ) water. For the model simulation. PBO loads were introduced in the environment consistent writh 10 applications. 1 week apart, beginning in June, EXAMS then simulated the late and distribution of PBO foiiowing such a treatment regimen. 

Fig. 3.7 Mutek DFR-04 (Photo courtesy of BTG). The Miitek DFR-04 Drainage Retention Freeness tester is the first laboratory unit that automatically detects the retention of fibres, fines and fillers. Within a few minutes it can be changed for drainage as well as freeness measurements. Advanced hardware and software allows simulation of paper machine conditions and evaluation of drainage and retention aids ...

Study on goaf spontaneous combustion prediction simulation of gas-drainage in spontaneously flammable and thick coal seam... 

Research on the evolution of drainage networks in a simulated loss watershed based on fractal dimension... 

Figure 2. The fitting maps for calculating box dimension of drainage networks in the simulated loess watershed.

Table 2. The Horton dimension values of drainage networks in the simulated watershed. ...

Compared with the box dimension and Horton dimension of drainage networks in six periods, the HI values of the simulated watershed keep reducing and the H(S) values of the watershed keep rising from the 1st to 6th period all the time. It reflects that there are some differences in the evolution process of drainage networks and the watershed which would deserve to be discussed in the future. 

Various tests, that are documented in detail in Holler (2006), have been performed to validate and verify the presented model. Among these were a simulation of air flow through dry sand, a drainage test after Liakopoulos, and a simulation of soil layer consolidation. In this section, the consolidation problem will be discussed. A fully-saturated soil layer of thickness h — m was subjected to a surface load of 0 = 10 kN/and width 2a = 2 w at time r = 0 s. The solution of the given example was carried out analytically and by means of numerical simulation. Figure 1 shows... 

The approach combines developments from three areas characterization of the model porous medium simulation of the drainage process within the model medium and computation of interfacial area and phase volumes for a given phase configuration. 

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