Effects of ambient pressure on the instability of a liquid boiling explosively at the superheat limit

Thesis/Dissertation · Tue Jan 01 04:00:00 EST 1985

OSTI ID:6864243

Frost, D L

The effect of ambient pressure on the dynamical behavior of a single droplet (1-2 mm diameter) of volatile liquid boiling explosively at the limit of superheat is studied experimentally and theoretically. Raising the ambient pressure lowers the superheat attained at the superheat limit, which decreases the vaporization rate. At high pressure, boiling consists of normal slow vaporization from a smooth interface. Observed bubble growth rates show reasonable agreement with theory. At intermediate pressures, a transitional regime of stability occurs in which a drop initially vaporizes stably for several milliseconds while incipient instability wave develop on the evaporating interface. When only a small amount of liquids remains in the drop in the shape of a thin cap, heat transfer from the surrounding hot host fluid initiates violent boiling at the edge of the liquid cap. The subsequent rapid vaporization generates a radiated pressure field two orders of magnitude larger than during stable boiling, and sets the bubble into violent oscillation. The bubble is subject to the Rayleigh Taylor instability and rapidly disintegrates into a cloud of small bubbles. Lowering the ambient pressure decreases the time delay between nucleation and onset of unstable boiling.

• Research Organization: California Inst. of Tech., Pasadena (USA)
• OSTI ID: 6864243
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420400* -- Engineering-- Heat Transfer & Fluid Flow
BOILING
BUBBLE GROWTH
BUBBLES
ENERGY TRANSFER
FLUIDS
HEAT TRANSFER
HEATING
INSTABILITY
LIQUIDS
NUCLEATE BOILING
PHASE TRANSFORMATIONS
PRESSURE EFFECTS
RAYLEIGH-TAYLOR INSTABILITY
SUPERHEATING