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In two-phase flows in which the properties of the two phases are vastly different, errors in the computation of the surface tension force at the interface cause Front-Capturing methods such as Volume of Fluid (VOF) and Level-Set method (LS) to develop interfacial spurious currents. To better solve such flows, special treatment is required to ...
The non-random two-liquid model [1] (abbreviated NRTL model) is an activity coefficient model introduced by Renon and Prausnitz in 1968 that correlates the activity coefficients of a compound with its mole fractions in the liquid phase concerned. It is frequently applied in the field of chemical engineering to calculate phase equilibria.
Phase-field models are usually constructed in order to reproduce a given interfacial dynamics. For instance, in solidification problems the front dynamics is given by a diffusion equation for either concentration or temperature in the bulk and some boundary conditions at the interface (a local equilibrium condition and a conservation law), [14] which constitutes the sharp interface model.
Different modes of two-phase flows. In fluid mechanics, two-phase flow is a flow of gas and liquid — a particular example of multiphase flow.Two-phase flow can occur in various forms, such as flows transitioning from pure liquid to vapor as a result of external heating, separated flows, and dispersed two-phase flows where one phase is present in the form of particles, droplets, or bubbles in ...
In chemistry, the lever rule is a formula used to determine the mole fraction (x i) or the mass fraction (w i) of each phase of a binary equilibrium phase diagram.It can be used to determine the fraction of liquid and solid phases for a given binary composition and temperature that is between the liquidus and solidus line.
In order to increase the calculation speed for viscosity calculations based on CS theory, which is important in e.g. compositional reservoir simulations, while keeping the accuracy of the CS method, Pedersen et al. (1984, 1987, 1989) [17] [18] [2] proposed a CS method that uses a simple (or conventional) CS formula when calculating the reduced ...
This is it for the analytical equations, but when the programmer transform the flow equation into a finite difference equation and further into a numerical algorithm, they are eager to minimize the number of computational operations. Here is an example with two constants that can be reduced to one by the fusion
where is the volume fraction of the fibers in the composite (and is the volume fraction of the matrix).. If it is assumed that the composite material behaves as a linear-elastic material, i.e., abiding Hooke's law = for some elastic modulus of the composite and some strain of the composite , then equations 1 and 2 can be combined to give