Scaling of two-phase flow regimes in a rod bundle with freon
Fluid to fluid modeling of the thermal-hydraulics of steam/water systems using Freon has been the subject of research for the past 25 years. However, there is as yet no universally accepted set of scaling laws to define the geometry and velocity scaling requirements of an equivalent Freon test of the full scale steam/water system being simulated. This paper describes a scaling concept where the Weber and Froud numbers of the Freon model are matched to that of the prototype being simulated, thus creating a comparable balance among inertia, surface tension and buoyancy forces. In this test it was demonstrated that similar flow regime transitions are observed in a half scale Freon simulation of a full scale steam/water test run at Dynatech. It is also shown using a two fluid analytical model and existing correlations for friction and interfacial momentum exchange from the open literature, that a half scale simulation leads to nearly the same slip ratio as for full scale steam/water, while the slip ratio for a full scale Freon simulation is too high. A comparison of the predicted flow distribution in the 4-rod bundle is made using the COBRA-IV code for a full scale simulation using Freon, a half scale simulation using Freon and full scale test with water. The COBRA results demonstrated that a half scale test section model using Freon yields a subchannel flow distribution similar to the steam/water case, while a full scale Freon simulation results in a distorted subchannel flow distribution. It is concluded that the appropriate geometric scale factor for Freon simulation of two-phase steam/water flow in tube bundles is one-half for a broad range of thermal-hydraulic conditions. 24 refs., 12 figs., 4 tabs.
- Research Organization:
- Knolls Atomic Power Lab., Schenectady, NY (USA)
- Sponsoring Organization:
- DOE/NE
- DOE Contract Number:
- AC12-76SN00052
- OSTI ID:
- 6892195
- Report Number(s):
- KAPL-4718; ON: DE90016661
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
42 ENGINEERING
99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE
REACTOR COOLING SYSTEMS
SIMULATION
TWO-PHASE FLOW
BUBBLES
C CODES
COMPARATIVE EVALUATIONS
COMPUTERIZED SIMULATION
FLOW MODELS
FREONS
HEAT TRANSFER
HYDRAULICS
HYDRODYNAMICS
INTERFACES
LOSS OF COOLANT
PRESSURE EFFECTS
REACTOR SAFETY
SCALE MODELS
SCALING LAWS
SHEAR
STEAM
TEMPERATURE EFFECTS
TRANSITION FLOW
WATER
ACCIDENTS
COMPUTER CODES
COOLING SYSTEMS
ENERGY SYSTEMS
ENERGY TRANSFER
FLUID FLOW
FLUID MECHANICS
HALOGENATED ALIPHATIC HYDROCARBONS
HYDROGEN COMPOUNDS
MATHEMATICAL MODELS
MECHANICS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
OXYGEN COMPOUNDS
REACTOR ACCIDENTS
REACTOR COMPONENTS
SAFETY
STRUCTURAL MODELS
220900* - Nuclear Reactor Technology- Reactor Safety
220100 - Nuclear Reactor Technology- Theory & Calculation
420400 - Engineering- Heat Transfer & Fluid Flow
990200 - Mathematics & Computers