Experimental two-phase liquid-metal magnetohydrodynamic generator program. Annual report, October 1976--September 1977

Technical Report · Mon May 01 00:00:00 EDT 1978

DOI:https://doi.org/10.2172/6869238· OSTI ID:6869238

Petrick, M; Fabris, G; Pierson, E S; Fischer, A K; Johnson, C E

Testing of the second diverging-channel generator with the revised ambient-temperature NaK-N/sub 2/ facility has been completed. The primary goal of the revised facility, demonstrating reduced slip ratio (ratio of gas velocity to liquid velocity) with higher liquid velocity (flow rate), was accomplished. The reduction in slip ratio was dramatically demonstrated by a series of consecutive runs with varying flow rate (from 6 kg/s to 12 kg/s for the liquid). Substantial increases in generator efficiency were obtained with higher liquid flow rates. Experiments to demonstrate that good liquid-to-gas heat transfer exists in the generator were successfully completed. Good heat transfer is essential because it is the almost-constant-temperature expansion of the gas (vapor) in the generator that yields the higher system efficiencies for liquid-metal MHD power cycles. The feasibility of generating relatively-stable bubbles, hence, a foam, in liquid metals has been demonstrated. Photographic documentation of these phenomena, both motion and still pictures, was made. Surface tension measurements and foaming experiments have shown that viscosity is also a factor in promoting bubble formation and persistence. Wetting and contact angle measurements have been made for stainless steel and carbon steel immersed in eutectic NaK. An analytical study of the liquid shunt (wall) layer sizes and losses has shown that these losses are not expected to be significant for large generators; less than 1.0 percent decrease in efficiency is anticipated. A two-phase pressure-gradient correlation developed for MHD flows has been shown to agree to within 20 percent with the generator data.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States)
• DOE Contract Number: W-31-109-ENG-38
• OSTI ID: 6869238
• Report Number(s): ANL/MHD-78-2; TRN: 79-000248
• Country of Publication: United States
• Language: English

Related Subjects

30 DIRECT ENERGY CONVERSION
LIQUID-METAL MHD GENERATORS
PERFORMANCE TESTING
TWO-PHASE FLOW
ANALYTICAL SOLUTION
BUBBLES
EFFICIENCY
END EFFECTS
EUTECTICS
FLOW RATE
FOAMS
HEAT TRANSFER
MAGNETIC FIELDS
MATHEMATICAL MODELS
MIXTURES
MOLTEN SALTS
NITROGEN
POTASSIUM
PRESSURE GRADIENTS
SLIP RATIO
SODIUM
SURFACE TENSION
TEST FACILITIES
VISCOSITY
ALKALI METALS
COLLOIDS
CRYOGENIC FLUIDS
DIRECT ENERGY CONVERTERS
DISPERSIONS
ELEMENTS
ENERGY TRANSFER
FLUID FLOW
FLUIDS
METALS
MHD GENERATORS
NONMETALS
SALTS
SURFACE PROPERTIES
TESTING
300104* - MHD Generators- Duct Engineering & Fluid Dynamics
300102 - MHD Generators- Performance & Testing