Study of nonequilibrium flashing of water in a converging-diverging nozzle. Volume 1: experimental

Technical Report · Mon Jun 01 04:00:00 EDT 1981

OSTI ID:6221124

Abuaf, N; Wu, B J.C.; Zimmer, G A; Saha, P

A steady water loop with well controlled flow and thermodynamic conditions was designed, built, and made operational for the measurement of net vapor generation rates under nonequilibrium conditions. The test section consists of a converging-diverging nozzle with 49 pressure taps and two observation windows at the exit. Pressure distributions, photographic observations, diametrical averaged centerline void fraction distributions, detailed transverse distributions of the chordal averaged void fractions at 27 axial locations, and area averaged void fraction distributions along the nozzle were recorded under various flashing conditions. The effects of various parameters were investigated and are reported here. The development of voids in nonequilibrium flashing flows is shown through the Oswatitsch integral to be dependent on three major factors of the void inception point which determines the initial and subsequent liquid superheats and must be accurately described; of the interfacial mass transfer rates, which depend on the local superheat and must be specified; and the local interfacial area density where the mass transfer occurs. The flashing onset correlation of Alamgir and Lienhard (1979) was extended to predict flashing inception in pipe and nozzle flows with subcooled inlet conditions. A void development model for bubbly flows (..cap alpha..<0.30) was based on a simple concept for interfacial area density in conjunction with a conduction-controlled bubble growth law. A general model of vapor generation following flashing inception was also developed. In this model, bubbly flow, bubbly-slug flow, a transitional flow comprising the annular and annular-mist regimes and finally fully dispersed droplet flow were assumed to occur at successively higher void fraction ranges. 163 figs., 23 tabs.

• Research Organization: Brookhaven National Lab., Upton, NY (USA)
• DOE Contract Number: AC02-76CH00016
• OSTI ID: 6221124
• Report Number(s): NUREG/CR-1864-Vol.1; BNL-NUREG-51317-Vol.1; ON: TI85015900
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
210100 -- Power Reactors
Nonbreeding
Light-Water Moderated
Boiling Water Cooled
210200 -- Power Reactors
Nonbreeding
Light-Water Moderated
Nonboiling Water Cooled
22 GENERAL STUDIES OF NUCLEAR REACTORS
220900* -- Nuclear Reactor Technology-- Reactor Safety
ACCIDENTS
BWR TYPE REACTORS
CONTAINERS
COOLING SYSTEMS
DATA ACQUISITION
DENSITOMETERS
DEPRESSURIZATION
ECCS
ENERGY SYSTEMS
ENERGY TRANSFER
ENGINEERED SAFETY SYSTEMS
FLASH HEATING
FLUID FLOW
HEAT TRANSFER
HEATING
HIGH TEMPERATURE
HYDROGEN COMPOUNDS
LOSS OF COOLANT
MASS TRANSFER
MATHEMATICAL MODELS
MEASURING INSTRUMENTS
MEDIUM TEMPERATURE
NOZZLES
OXYGEN COMPOUNDS
PHASE VELOCITY
PHOTOMETERS
PRESSURE GRADIENTS
PWR TYPE REACTORS
REACTOR ACCIDENTS
REACTOR COMPONENTS
REACTOR COOLING SYSTEMS
REACTOR PROTECTION SYSTEMS
REACTOR SAFETY
REACTOR VESSELS
REACTORS
SAFETY
TEMPERATURE GRADIENTS
THERMODYNAMICS
VELOCITY
VOID FRACTION
VOIDS
WATER
WATER COOLED REACTORS
WATER MODERATED REACTORS