Evaporation waves in superheated dodecane

Abstract

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.

Dynamical freeze-out in three-fluid hydrodynamics

“…Physics of this process is studied both experimentally and theoretically [48,49,50,51]. Evaporation from free surface of normal (not superheated) fluid is a very slow process.…”

“…In our simplified version of the "continuous emission", λ mfp = 0 in the fluid phase and λ mfp → ∞ in the gas phase. Therefore, a particle can escape only from the free surface, which cannot move inward the system faster than with the speed of sound [51].…”

Molecular interpretation of nonclassical gas dynamics of dense vapors under the van der Waals model

“…1 A detailed description of wave propagation in vapors exhibiting both positive and negative ⌫ regions, including the effects of viscosity and thermal conductivity, is given by Cramer and Kluwick. 25 Although experimental evidence of nonclassical gas dynamics in two-phase vapor/liquid [26][27][28][29][30] or solid/solid 31 systems has been documented in the past decades, no experimental proof of nonclassical phenomena in the vapor phase is currently available, with the only exception of the experiment of Borisov et al 5 in 1983, see also Kutateladze et al. 32 Yet the interpretation of the results presented in Refs.…”

An experimental investigation of rapid boiling of $$\hbox {CO}_{2}$$ CO 2

“…Simoes-Moreira and Shepherd [3] also performed a series of experiments with superheated dodecane. Reinke and Yadigaroglu [4] did a series of experiments with explosive vaporization in propane, butane and refrigerant R-134a.…”