An Experimental Study of Evaporation Waves in a Superheated Liquid

Hill, Larry

doi:10.1007/978-3-642-83587-2_3

Cited by 51 publications

(33 citation statements)

References 6 publications

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“…This implies that -stand higher pressure; in other words, it represents the contributions of the wall friction and shear stress in highly viscous starch syrup foam that balance the kinetic energy of its motion. Further, these effects are more clearly observable in this study than in previous experiments that employed other analogue materials; the decompressions in superheated liquids (Hill and Sturtevant, 1990), GRA system (Phillips, et al, 1995), and CO 2 saturated water Sparks et al, 1994;Mader et al, 1996;Zhang et al, 1997) show a more rapid acceleration of the fragmented foam with a constant acceleration regime ( V t 2 ).…”

Section: Fragmentation Processcontrasting

confidence: 44%

Model experiment on magma fragmentation in explosive volcanic eruption

Yamamoto

Takayama

Ishikawa

2008

Journal of Mineralogical and Petrological Sciences

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A new experimental facility has been developed to investigate the fragmentation of vesicular magma undergoing rapid decompression. The facility based on a vertical shock tube was designed and constructed to produce starch syrup foams of high void fraction but low permeability, high liquid viscosity, and at high pressure as alternative to foamy magma exposed to expansion waves. The highly viscous material (starch syrup) of dynamic shear viscosities ranging from 5 to 10 12 Pa s were intermixed with nitrogen gas bubbles under 1.6 to 2.6 MPa and were subsequently loaded into an acrylic test section. The foamy starch syrup was pressurized up to 2.6 MPa and then rapidly decompressed to 0.1 MPa, which caused its fragmentation and simultaneous ejection of the fragmentation products into a large -volume chamber. In ejecting high -pressure foam into a low -pressure chamber, the foam's fragmentation process was characterized with the help of pressure measurements and highspeed video recording. Prior to decompression experiments, we examined the viscoelastic properties of the foam specimens by using a rheometer. The rapid decompression generated wide varieties of fragment shapes with smooth or conchoidal fracture. The results prove that a shock dynamic approach is effective to model magma fragmentations.

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Section: Fragmentation Processcontrasting

confidence: 44%

Model experiment on magma fragmentation in explosive volcanic eruption

Yamamoto

Takayama

Ishikawa

2008

Journal of Mineralogical and Petrological Sciences

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“…Chaves et al (1987) suggested that the onset of evaporation occurs upon the arrival of the first rarefaction wave reflected from the bottom of the test cell. Hill (1991) observed that the time delay between the first expansion wave and wave onset was enough to accommodate several acoustic transits in his experiments with refrigerants. Our results are consistent with Hill's findings and we refer the reader to his excellent photographs and discussion of the startup process, in which an evaporation front spreads across the initially quiescent surface and develops into an unstable evaporation wave.…”

Section: Resultsmentioning

confidence: 99%

“…Previous experimental studies (Chaves et al 1985;Hill 1991) in confined flows have resulted only in twophase downstream states. Kurschat, Chaves & Meier (1992) were able to obtain complete evaporation when they allowed highly-superheated liquid to expand radially as a supersonic jet in a low-pressure chamber.…”

Section: Complete Evaporation Wavesmentioning

confidence: 99%

“…Under specific conditions, described below, a superheated liquid will evaporate in a wave-like process; that is, the phase change process is confined to a discrete and observable zone, which moves into the undisturbed metastable liquid and a two-phase mixture is observed downstream of the wave front (Terner 1962;Grolmes & Fauske 1974; Thompson et al 1987;Hill 1991;Simões-Moreira 1994;Simões-Moreira & Shepherd 1994). The occurrence of the evaporation wave depends on several factors: the thermodynamic properties of the substance, the degree of superheat, the absence of activated nucleation sites, and the depressurization time scale.…”

Section: Introductionmentioning

confidence: 99%

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Evaporation waves in superheated dodecane

Simões-Moreira¹,

Shepherd

1999

J. Fluid Mech.

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We have observed propagating adiabatic evaporation waves in superheated liquid dodecane, C 12 H 26 . Experiments were performed with a rapid decompression apparatus at initial temperatures of 180-300 • C. Saturated dodecane in a tube was suddenly depressurized by rupturing a diaphragm. Motion pictures and still photographic images, and pressure and temperature data were obtained during the evaporation event that followed depressurization. Usually, a front or wave of evaporation started at the liquid free surface and propagated into the undisturbed regions of the metastable liquid. The evaporation wave front moved with a steady mean velocity but the front itself was unstable and fluctuating in character. At low superheats, no waves were observed until a threshold superheat was exceeded. At moderate superheats, subsonic downstream states were observed. At higher superheats, the downstream flow was choked, corresponding to a Chapman-Jouguet condition. At the most extreme superheat tested, a vapour content of over 90% was estimated from the measured data, indicating a nearly complete evaporation wave. Our results are interpreted by modelling the evaporation wave as a discontinuity, or jump, between a superheated liquid state and a two-phase liquid-vapour downstream state. Reasonable agreement is found between the model and observations; however, there is a fundamental indeterminacy that prevents the prediction of the observed wave speeds.

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“…The phase transition in channels with different shapes was studied in the paper [2] and it was shown that the wave speed is independent from the channel diameter and its shape. This paper continues the experimental study of [3] and [4]. In these articles, the adiabatic evaporation waves were investigated during the rapid transition of Freon in the metastable state after pressure relief.…”

Section: Introductionmentioning

confidence: 99%

Experimental study of metastable liquids decay during depressurization in cylindrical channel

2017

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Abstract. Patterns of the nonequilibrium phase transitions during propagation of an adiabatic wave phase transition in metastable refrigerants R141b, R113 and pentane C5H12 were experimentally established. Experiments were carried out in a wide range of initial temperatures and pressures in a transparent cylindrical channel. Visualization of liquids decay was performed using high-speed video camera.

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An Experimental Study of Evaporation Waves in a Superheated Liquid

Cited by 51 publications

References 6 publications

Model experiment on magma fragmentation in explosive volcanic eruption

Model experiment on magma fragmentation in explosive volcanic eruption

Evaporation waves in superheated dodecane

Experimental study of metastable liquids decay during depressurization in cylindrical channel

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