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

Conference · Sat Dec 31 23:00:00 EST 1983

OSTI ID:5961207

Sturtevant, B; Frost, D

The effect of ambient pressure on the intrinsic instability of rapid vaporization in single droplets boiling explosively at the limit of superheat has been studied experimentally and theoretically in a series of experiments with pentane, isopentane and ethyl ether in a bubble-column apparatus it has been shown that the baroclinic interfacial instability may be suppressed by increasing the ambient pressure. High-speed microphotography shows that, while at atmospheric pressure bubble boundaries are rough and opaque, at elevated pressure the liquid-vapor interface is smooth and transparent. Pressure measurements show that the radiated pressure field is two orders of magnitude smaller from stabilized bubbles than from unstable. At intermediate pressures bubble growth occurs in two stages, first stable, then unstable. The transitional regime between unstable and stable vaporization provides convenient conditions for exhibiting many features of unstable vaporization. The Landau mechanism for the instability of laminar flames has been adapted to the case of vaporization by accounting for the effects of surface tension and acceleration. A formulation of the theory in spherical geometry predicts absolute stability at atmospheric pressure, while the theory for planar interfaces yields results in general agreement with observation. Apparently the instability occurs at such small wavelengths that the spherical constraint is inappropriate. Furthermore, its high sensitivity to temperature suggests that small temperature nonuniformities may be responsible for quantitative departures of the behavior from predictions. 22 references, 16 figures.

• Research Organization: California Inst. of Tech., Pasadena (USA). Graduate Aeronautical Labs.
• DOE Contract Number: AT03-80ER10634
• OSTI ID: 5961207
• Report Number(s): CONF-841201-32-App.; ON: DE85009476
• Country of Publication: United States
• Language: English

Related Subjects

2-METHYLBUTANE
45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEFENSE
450100* -- Military Technology
Weaponry
& National Defense-- Chemical Explosions & Explosives
ALKANES
BOILING
BUBBLES
DIAGRAMS
DROPLETS
ETHERS
ETHYL ETHER
EVAPORATION
EXPLOSIONS
FLAMES
FLUIDS
FRAGMENTATION
GASES
HEATING
HYDROCARBONS
INSTABILITY
INTERFACES
LIQUIDS
NUCLEATION
ORGANIC COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
PARTICLES
PENTANE
PHASE DIAGRAMS
PHASE TRANSFORMATIONS
PRESSURE EFFECTS
SUPERHEATING
SURFACE PROPERTIES
SURFACE TENSION
VAPORS