Two-phase flow regime transition criteria in post-dryout region based on flow visualization experiments

Technical Report · Mon Jun 01 04:00:00 EDT 1987

OSTI ID:6302828

Obot, N T; Ishii, M

A visual study of film boiling using photographic and high speed motion-picture methods was carried out to determine the flow regime transition criteria in the post-CHF region. An idealized inverted annular flow was obtained by introducing a liquid jet of Freon 113 through a nozzle, precisely centered with respect to the internal diameter of the test section, with an annular gas flow. The respective ranges for liquid and gas exit velocities were 0.05 to 0.5 and 0.03 to 7.9 m/s. Nitrogen and helium were used in the study. For the present configuration, there are four basic flow regimes. Beginning from the nozzle exit, there is a smooth, inverted annular flow section with liquid in the core and gas in the annulus; followed by the rough wavy section with an intact liquid core, the agitated and the dispersed flow regimes. For a given liquid jet velocity, the axial extent of each flow regime decreases with increasing gas velocity through the annulus. Generalized transition criteria and simplified correlations for the axial limits of the various flow regimes have been developed, by extending the results of previous studies on adiabatic inverted annular flow.

• Research Organization: Argonne National Lab., IL (USA); Nuclear Regulatory Commission, Washington, DC (USA). Div. of Accident Evaluation
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 6302828
• Report Number(s): NUREG/CR-4972; ANL-87-27; ON: TI87013015
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
220900* -- Nuclear Reactor Technology-- Reactor Safety
42 ENGINEERING
420400 -- Engineering-- Heat Transfer & Fluid Flow
BOILING
DATA
DRYOUT
ELEMENTS
EXPERIMENTAL DATA
FILM BOILING
FLUID FLOW
FLUIDS
GASES
HELIUM
INFORMATION
NITROGEN
NONMETALS
NUMERICAL DATA
PHASE TRANSFORMATIONS
RARE GASES
REACTOR SAFETY
REACTOR SAFETY EXPERIMENTS
SAFETY
TWO-PHASE FLOW