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ISSN Online: 2377-424X

ISBN Print: 0-89116-130-9

International Heat Transfer Conference 6
August, 7-11, 1978, Toronto, Canada

THE DYNAMICS OF TWO-PHASE FLOW IN A DUCT

Get access (open in a dialog) DOI: 10.1615/IHTC6.690
pages 345-350

Resumo

The instantaneous, three dimensional form of the conservation equations for transient flow boiling is reduced to an ensemble averaged one dimensional form by using certain mathematical theorems and postulates. The resulting set of equations may be solved numerically for the case where the averaged velocities, temperatures and pressures in each phase at the same cross-section are all unequal (unequal velocity, unequal temperature, unequal pressure model − UVUTUP). We show that the UVUTUP equations have real characteristics.
However, information is lost in the averaging process and it becomes necessary to use empirical correlations for heat, mass and momentum transfer between the phases, and between the duct wall and each phase. To reduce the empirical information required, we use certain additional postulates to derive two simpler flow boiling models, EVETEP and EVUTEP. The former (EVETEP) produces a set of three first order partial differential equations, and the latter (EVUTEP) five. Both of these sets are hyperbolic. The method of characteristics and a finite difference form based on the method of characteristics have been used to obtain results for both models. The results are compared with data from a simple blowdown experiment.