![]() Note that the inhomogeneous model is not same as separated flow model. ![]() The homogeneous model is also known as "friction factor" or "fog flow" model where two-phase flow is considered as single phase flow possessing mean flow properties. *Same pressure field shared by all phases. Homogeneous or inhomogeneous turbulence field Momentum equations for each phase: interfacial forces ** acting on each phase causes momentum transfer Mixture momentum equation: momentum transfer between phases is assumed to be very large Interphase mass and momentum transfer are considered There is no interphase mass and momentum transfer The differences are tabulated below.Īll phases move at same velocity, same flow field Another broad classification of multiphase flows are 'homogeneous' and 'inhomogeneous'. Three such types namely bully, slug and annular are described in later paragraphs. Gas-liquid flows are further grouped into many categories depending upon the distribution and shape of gas parcels. On the other hand, the adjective "Eulerian" is used to describe correlations between two fixed points in a fixed frame of reference - such as counting the type of vehicles and their speeds while passing through a fixed point on the road. The adjective "Lagrangian" indicates that it relates to the phenomena of tracking a moving points ("fluid particles") - such as tracking a moving vehicle on a road. In a multi-phase flow, one of the phase is usually continuous (carrier phase) and the other phase(s) are dispersed in it. As can be seen, the immiscibility is a important criteria. Multiphase flow regimes are typically grouped into five categories: gas-liquid (which are naturally immiscible) flows and (immiscible) liquid-liquid flows, gas-solid flows, liquid-solid flows, three or more phase flows. For example, water flowing through packed bed of rocks is a single phase flow. In a multiphase flow, the interface between the phases are influenced by motion of fluid. Some of the general characteristics and categories of multi-phase flow are described below before moving to actual application of OpenFOAM utilities. Multi-phase flows have wide applications in process, refrigeration, air conditioning, petroleum, oil and gas, food processing, automotive, power generation and metal industries including phenomena like mixing, particle-laden flows, CSTR - Contunuously Stirred Tanks Reactor, Water Gas Shift Reaction (WGSR), fluidized bed, fuel injection in engines, bubble columns, mixer vessels, Lagrangian Particle Tracking (LPT). Multi-phase Flow in OpenFOAM Multi-phase Flows and Discrete Phase Models
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