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

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)

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

HEAT TRANSFER FEATURES IN DIELECTRIC FLUIDS IN THE COURSE OF NON-STATIONARY HEATING OVER A WIDE RANGE OF PRESSURES

Heat transfer in dielectric fluids in the course of non-stationary heating is discussed. The method of pulse heating of a wire probe was chosen for carrying out experiments. Authors revealed threshold deterioration of heat transfer in the case of fast transition to supercritical state of fluid.Работа выполнена в рамках проекта РНФ № 19-19-00115

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

a b s t r a c t 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 thermoph ysical 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 conductio n 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