Dynamics of gas bubble growth in a supersaturated solution with Sievert's solubility law

This paper presents a theoretical description of diffusion growth of a gas bubble after its nucleation in supersaturated liquid solution. We study systems where gas molecules completely dissociate in the solvent into two parts, thus making Sievert's solubility law valid. We show that the difference between Henry's and Sievert's laws for chemical equilibrium conditions causes the difference in bubble growth dynamics. Assuming that diffusion flux is steady we obtain a differential equation on bubble radius. Bubble dynamics equation is solved analytically for the case of homogeneous nucleation of a bubble, which takes place at a significant pressure drop. We also obtain conditions of diffusion flux steadiness. The fulfillment of these conditions is studied for the case of nucleation of water vapor bubbles in magmatic melts.Comment: 22 pages, 3 figure

Viscoelasticity and metastability limit in supercooled liquids

A supercooled liquid is said to have a kinetic spinodal if a temperature Tsp exists below which the liquid relaxation time exceeds the crystal nucleation time. We revisit classical nucleation theory taking into account the viscoelastic response of the liquid to the formation of crystal nuclei and find that the kinetic spinodal is strongly influenced by elastic effects. We introduce a dimensionless parameter \lambda, which is essentially the ratio between the infinite frequency shear modulus and the enthalpy of fusion of the crystal. In systems where \lambda is larger than a critical value \lambda_c the metastability limit is totally suppressed, independently of the surface tension. On the other hand, if \lambda < \lambda_c a kinetic spinodal is present and the time needed to experimentally observe it scales as exp[\omega/(\lambda_c-\lambda)^2], where \omega is roughly the ratio between surface tension and enthalpy of fusion

Model of Non-stationary Heat Transfer in a Supercritical Fluid

This paper continues the process of reconciling results obtained when investigating heat transfer in the supercritical liquid–vapor region inherent in stationary and fast processes. A relatively simple model of non-stationary heat transfer at the microscopic level in a non-idealized system is constructed. The model provides a possible explanation for the increase in the thermal resistance of a supercritical fluid (drop in heat conduction) at a not too great distance from the critical isobar on a scale of small characteristic times and sizes. The model is based on an explicit account of a significant decrease in thermal diffusivity when approaching the critical temperature of the substance. The simulation results are compared with experimental data on the rapid (lasting in units-tens of milliseconds) transfer of a compressed liquid to the supercritical temperature region along a supercritical isobar. © 2023, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.Russian Science Foundation, RSF: 19-19-00115-PThis study was supported by the Russian Science Foundation (Project No. 19-19-00115-P)

Heat transfer under high-power heating of liquids. 1. Experiment and inverse algorithm

A new approach to fluids behavior study in the course of highpower heating has been developed by us. The approach combines experimental method of controlled pulse heating of a wire probe and numerical method of thermophysical properties temperature dependencies recovery from the experimental data. Short (millisecond) characteristic time scale allows working with short-lived fluids, including superheated (with respect to the liquid-vapor equilibrium temperature and/or to the temperature of thermal decomposition onset) ones. Numerical method gives a set of inverse heat conduction problem solutions, based on the results of single pulse experiment. Numerical technique, based on the heat transfer parameters optimization model, is built using genetic algorithms. The approach was applied to saturated hydrocarbons in the temperature range 300-625 K. © 2013 Elsevier Ltd. All rights reserved

Anomaly in the stability limit of liquid helium 3

We propose that the liquid-gas spinodal line of helium 3 reaches a minimum at 0.4 K. This feature is supported by our cavitation measurements. We also show that it is consistent with extrapolations of sound velocity measurements. Speedy [J. Phys. Chem. 86, 3002 (1982)] previously proposed this peculiar behavior for the spinodal of water and related it to a change in sign of the expansion coefficient alpha, i. e. a line of density maxima. Helium 3 exhibits such a line at positive pressure. We consider its extrapolation to negative pressure. Our discussion raises fundamental questions about the sign of alpha in a Fermi liquid along its spinodal.Comment: 5 pages, 3 figure

THERMOPHYSICAL MONITORING OF MOISTURE IN HYDRAULIC LIQUIDS

The technique of fast thermal control has been applied for the examination of samples of hydraulic liquids with a water content from 0,1 to 3,5 %. Appropriate operating modes of the measuring device were found.Работа выполнена в рамках проекта РФФИ № 16-08-00381 и проекта комплексной программы Уральского отделения РАН № 18-2-2-3

Cavitation Inception on Microparticles: A Self-Propelled Particle Accelerator

Corrugated, hydrophilic particles with diameters between 30 �m and 150 �m are found to cause cavitation inception at their surfaces when they are exposed to a short, intensive tensile stress wave. The growth of cavity and its interaction with the original nucleating particle is recorded by means of digital imaging. The growing cavity accelerates the particle into translatory motion until the tensile stress decreases, and subsequently the particle separates from the cavity. The cavity growth and particle detachment are modeled by considering the momentum of the particle and the displaced liquid. The analysis suggests that all particles which cause cavitation are accelerated into translatory motion, and separate from the cavities they themselves nucleate

Intensification of heat transfer during spinodal decomposition of a superheated aqueous oligomer solution

The heat conduction of an aqueous solution of polypropylene glycol in the region of stable and unstable states was studied by the method of pulse isothermal impact on a substance with a characteristic time of 100 ms. It has been shown that the short-Term superheating of a homogeneous solution not only above the liquid-liquid equilibrium temperature (low critical solution temperature), but also above the diffusion spinodal is fundamentally possible. The negative character of the deviation of the heat conduction of a solution from the additive law calculated from the heat conduction of the pure components at a given temperature was revealed. The signs of manifestation of spinodal decomposition accompanied by a significant intensification of heat transfer were found. © Published under licence by IOP Publishing Ltd

Study of Heat Transfer by Partially-Miscible Mixture with LCST in Pulse Heating Experiments

Heat transfer by mixture with the lower critical solution temperature in the course of non-stationary heating is discussed. The superheating degree reached 200 K at the heating rate of 105 K/s. Upon reaching a certain superheating degree, a significant enhancement of heat transfer has been revealed.Работа выполнена в рамках проекта РНФ № 19-19-00115

THERMAL CONDUCTIVITY OF OVERHEATED BINARY SOLUTIONS

In this work we investigate the following hypothesis: placement of a second substance in the pure system leads to the appearance of additional thermal resistance. In order to prove it, a we used temperature plateau method. By means of which, we determined the values of the additional thermal resistance of the following solutions: isopropanol-water, isopropanol-ethylene glycol, isopropanol-triethylene glycol, and triethylene glycol-water. Experiments were carried out at atmospheric pressure and temperatures of the samples up to 180 °С