A nonequilibrium vapor generation model for flashing flows

Journal Article · Wed Feb 01 04:00:00 EST 1984 · J. Heat Transfer; (United States)

DOI:https://doi.org/10.1115/1.3246634· OSTI ID:7021896

Saha, P; Abuaf, N; Wu, B J.C.

A nonequilibrium vapor generation model for flashing flows is presented. The model consists of a flashing inception point, a bubbly flow regime followed by a bubbly-slug regime, an annular or annular-mist regime, and finally a dispersed-droplet regime. Existence of superheated liquid at the inception point and beyond is recognized. The vapor generation rate is calculated from the flow-regime dependent interfacial area density and net interfacial heat flux. However, the bubble number density at the flashing inception point was varied to obtain optimum fits with the void fraction data taken in a vertical converging-diverging nozzle. The interfacial area density at the inception point, thus determined, showed a rapid increase with the decrase in the liquid superheat at this point. This trend is plausible, since in the limit of thermal equilibrium flow where the liquid superheat approaches zero, the interfacial area for heat and mass transfer should be very large.

• Research Organization: Department of Nuclear Energy, Brookhaven National Laboratory, Upton, New York 11973
• OSTI ID: 7021896
• Journal Information: J. Heat Transfer; (United States), Journal Name: J. Heat Transfer; (United States) Vol. 106:1; ISSN JHTRA
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420400* -- Engineering-- Heat Transfer & Fluid Flow
BUBBLES
ENERGY TRANSFER
EVAPORATION
FLASHING
FLUID FLOW
HEAT TRANSFER
MATHEMATICAL MODELS
NOZZLES
NUCLEATION
PHASE TRANSFORMATIONS
TWO-PHASE FLOW