Experimental research into the boiling-up of a free jet of superheated water discharging through a short cylindrical nozzle with sharp inlet and outlet edges into the atmosphere has been carried out.The change in the ...Experimental research into the boiling-up of a free jet of superheated water discharging through a short cylindrical nozzle with sharp inlet and outlet edges into the atmosphere has been carried out.The change in the shape of a liquid jet has been traced through changes in thermodynamic parameters(temperature,pressure)along the saturation line in both the visible range and the infrared spectrum.The flow shapes corresponding to various modes of boiling-up have been identified.With thermal-imaging diagnostics,heterogeneities in the spray plume of a superheated liquid jet have been recorded and temperature distributions have been obtained in various sections of a boiling-up flow.The maximum temperature in the flare of a boiling-up jet has been determined at different distances from the short nozzle’s exit edge.展开更多
The article considers a relaxation of the water/polypropylene glycol-425 solution with a lower critical solution temperature(LCST)following its pulsed superheating concerning liquid-liquid and liquid-vapor equilibrium...The article considers a relaxation of the water/polypropylene glycol-425 solution with a lower critical solution temperature(LCST)following its pulsed superheating concerning liquid-liquid and liquid-vapor equilibrium lines,as well as the liquid-liquid spinodal.Superheating was performed using the pulsed heat generation method in a micro-sized wire probe.The main heating mode was the constant(over the pulse length)power mode.Characteristic heating rates ranged from 0.05×10^(5) to 2×10^(5) K/s,while the degree of superheating concerning the spinodal was up to 200 K.The temperature of spontaneous boiling-up and the amplitude of the corresponding signal were monitored as functions of the heating rate set by the power value.The results demonstrate an example of the interaction of liquidliquid and liquid-vapor phase transitions,as well as the spinodal decomposition of a solution with LCST against the background of its unstable states.We proposed a physical model to explain the minimum spontaneous boiling-up temperature revealed within a certain range of heating rates,which is not typical of completely miscible solutions.Further research will focus on establishing a general criterion for the possibility of spinodal decomposition of such solutions under the conditions of rapid heating.展开更多
文摘Experimental research into the boiling-up of a free jet of superheated water discharging through a short cylindrical nozzle with sharp inlet and outlet edges into the atmosphere has been carried out.The change in the shape of a liquid jet has been traced through changes in thermodynamic parameters(temperature,pressure)along the saturation line in both the visible range and the infrared spectrum.The flow shapes corresponding to various modes of boiling-up have been identified.With thermal-imaging diagnostics,heterogeneities in the spray plume of a superheated liquid jet have been recorded and temperature distributions have been obtained in various sections of a boiling-up flow.The maximum temperature in the flare of a boiling-up jet has been determined at different distances from the short nozzle’s exit edge.
基金the expense of a grant of the Russian Science Foundation(project No.23-69-10006),https://rscf.ru/project/23-69-10006/(accessed on 6 May 2025).
文摘The article considers a relaxation of the water/polypropylene glycol-425 solution with a lower critical solution temperature(LCST)following its pulsed superheating concerning liquid-liquid and liquid-vapor equilibrium lines,as well as the liquid-liquid spinodal.Superheating was performed using the pulsed heat generation method in a micro-sized wire probe.The main heating mode was the constant(over the pulse length)power mode.Characteristic heating rates ranged from 0.05×10^(5) to 2×10^(5) K/s,while the degree of superheating concerning the spinodal was up to 200 K.The temperature of spontaneous boiling-up and the amplitude of the corresponding signal were monitored as functions of the heating rate set by the power value.The results demonstrate an example of the interaction of liquidliquid and liquid-vapor phase transitions,as well as the spinodal decomposition of a solution with LCST against the background of its unstable states.We proposed a physical model to explain the minimum spontaneous boiling-up temperature revealed within a certain range of heating rates,which is not typical of completely miscible solutions.Further research will focus on establishing a general criterion for the possibility of spinodal decomposition of such solutions under the conditions of rapid heating.
