V 28 Vapor Pressures, Enthalpies of Vaporization, and Critical Parameters of a Series of Linear Aliphatic Dimethyl Esters of Dicarboxylic Acids [Текст] / S. P. Verevkin, S. A. Kozlova, V. N. Emel'yanenko, E. D. Nikitin, A. P. Popov, E. L. Krasnykh // Journal of Chemical & Engineering Data. - 2006. - Vol. 51, № 5. - С. 1896-1905 Рубрики: ФИЗИКА Кл.слова (ненормированные): VAPOR PRESSURES Аннотация: Vapor pressures and the molar enthalpies of vaporization of the linear aliphatic dimethyl esters of dicarboxylic acids CH3-CO2-(CH2)n-CO2-CH3 with n = (0 to 8) have been determined by the transpiration method. A linear correlation of enthalpies of vaporization (at T = 298.15 K) of the esters studied with the number n and with the Kovat's indices and has been found. The critical temperatures and pressures of the esters with n = (0 to 6) and n = 8 have been measured by the pulse-heating method with the residence times ranging from (0.03 to 1) ms. Experimental data on the critical properties are compared with the estimations by group contribution methods by Constantinou and Gani and by Marrero and Gani. Both methods considerably underestimate the critical temperatures of the esters studied; however, the method by Marrero and Gani provides the prediction of the critical pressures of the esters with an average absolute error approximately equal to the uncertainty of the measurements. ?? \\\\Expert2\\NBO\\Journal of Chemical and Engineering Data\\2006, v.51, p.1896.pdf |
P 34 Pavlov, P. A. Vaporization in Polymer Liquids under Conditions of Rapid Heating [] / P. A. Pavlov, P. V. Skripov // High Temperature. - 1998. - V.36, N3. - С. 448-455 Рубрики: ФИЗИКА Кл.слова (ненормированные): VAPORIZATION -- LIQUID POLYMER -- HEATING RAPID -- POLYMER |
F 17 Faizullin, M. Z. New universal relationships for surface tension and vaporization enthalpy of non-associated liquids / M. Z. Faizullin // Fluid Phase Equilibria. - 2003. - Vol.211, №1. - С. 75-83 Рубрики: ФИЗИКА Кл.слова (ненормированные): VAPOR-LIQUID -- METHOD OF CALCULATION -- ENTHALPY OF VAPORIZATION Аннотация: The methodology of thermodynamic similarity has been used to study the relation between the surface tension of a liquid and the vaporization enthalpy calculated per unit volume of the liquid phase. Simple reliable relationships that do not contain substance dependent parameters have been found. A new universal one-parameter relationship for the temperature dependence of the vaporization enthalpy has been suggested. The results of calculations with the use of these relationships are compared with experimental data |
P 34 Pavlov, P. A. Thermodynamic crisis of boiling / P. A. Pavlov // Journal of Engineering Thermophysics. - 2007. - Vol.16, №3. - С. 145-154 Рубрики: ФИЗИКА Кл.слова (ненормированные): VAPOR -- LOOP HEAT PIPE Аннотация: The procedure of calculation of the dynamics of rapid near-wall vaporization near a metallic heater is considered. A physical model of explosive boiling-up on bubbles of fluctuation origin is used. The model is limited to regimes when the motion of bubbles can be ignored and convective flows do not have enough time to develop. It is assumed that the dry spot under a bubble thermally insulates the heater wall. The heat removal is provided by the vicinity of the wetting line (WL). An analytical calculation has become possible on the basis of the well-known exact solution to the problem of the temperature field near the wetting line. Generalization of this solution has led to two new problems. These are the problem of allowance for the difference of the dynamic wetting angle from the right angle and that of allowance for thermocapillary flows. A numerical comparison of the results of calculation of the dry area with the use of different methods of allowing for the “tightness” effect in the dynamics of bubble generation and growth has been made. The evolution of bubbles from their generation to growth limited by the heat supply has been investigated. It has been found that the transition stage in the development of bubbles from Rayleigh to thermal ones is of considerable importance in the processes of explosive boiling-up. The dynamics of change in the dry area and wetting line length prior to the stage of bubble merging into a vapor film has been calculated. A condition of passage of the heat flux through a maximum is found. The applicability of the idea of thermodynamic crisis to calculations of miniature devices is justified. The problem of constructing a model to calculate the interphase surface shape near the wetting line under a developed thermocapillary flow and considerable reactive forces of the vapor flow is formulated. The model is in good agreement with the results of experiments on pulsed superheating of liquids at a rate higher than 1 K/μs |
T 82 Transient behavior of superheated water jets boiling [Электронный ресурс] / A. V. Reshetnikov, K. A. Busov, N. A. Mazheiko, V. N. Skokov, V. P. Koverda // Thermophysics and Aeromtchanics. - 2012. - Vol.19, №2. - P329-336 Рубрики: ФИЗИКА Кл.слова (ненормированные): 1/f FLUCTUATIONS -- JET FORMS -- NUCLEATION FREQUENCY Аннотация: Superheated water flowing out from high-pressure chamber through short cylindrical and slot channel has been studied experimentally. Relation of vaporization mechanisms in superheated liquid (boiling in single, not interacting centers, intense heterogeneous vaporization, and homogeneous fluctuating nucleation) and respective forms of superheated water jets has been determined. Temperature intervals with transient behavior of boiling have been determined. It is shown that at transient behavior of boiling the amplitude of pulsations of jet parameters increases, and in the spectra of pulsation power, the low-frequency component 1/f appears |
P 34 Pavlov, P. A. Dynamics of vapor film formation upon rapid superheating of liquid [Electronic resource] / P. A. Pavlov, V. E. Vinogradov // High Temperature. - 2010. - Vol.48, №5. - P683-690. - Bibliogr. : p. 690 (18 ref.) Рубрики: ФИЗИКА Кл.слова (ненормированные): VAPOR FILM -- SUPERHEATING OF LIQUID -- DYNAMICS Аннотация: The formation of a vapor film on a heater in the modes of rapid near-wall superheating of liquid at positive and negative pressures is considered. A model of this phenomenon and a technique for calculating the vaporization front velocity are proposed. Tests of this model in experiments with n-heptane at pressures from −2 to +0.2 MPa and heating rates of ∼0.5 K/μs showed a significant effect of capillary forces on the dynamics of vapor film form \\\\expert2\\NBO\\High Temperature\\2010, v. 48, N 5, p.683.pdf |
D 63 Disintegration of flows of superheated liquid films and jets [Electronic resource] / A. N. Pavlenko, V. P. Koverda, A. V. Reshetnikov, A. S. Surtaev, A. N. Tsoi, N. A. Mazheiko, K. A. Busov, V. N. Skokov // Journal of Engineering Thermophysics. - Bibliogr. : p. 192-193 (65 ref.) Рубрики: ФИЗИКА Кл.слова (ненормированные): CYLINDRICAL CHANNEL -- EXPERIMENTAL INVESTIGATIONs -- BOILING INCIPIENCE Аннотация: This paper represents results on investigating the dynamics of boiling and disintegration of superheated liquid films and jets. The first part deals with experimental study of boiling liquid outflow through short cylindrical and slit channels. Evolution of disintegration of a hot water jet flow is observed both at low and moderate superheating and at high and limit superheating, and also for vaporization mechanisms corresponding to these superheatings. Peculiarities of disintegration of jets through slit and cylindrical channels are noticed. Results on measuring the reactive thrust of the jet through a slit channel under different geometrical conditions behind the channel outlet are represented. The 1/f fluctuations in transient regimes of superheated liquid boiling and in transient regimes of behavior of the jet shape are found. The second part of this article represents results on experimental investigation of nonsteady heat transfer and dynamics of the development of crisis phenomena at boiling of a falling subcooled liquid film in the conditions of stepwise heat release. The experimental data were obtained using synchronized high-speed infrared thermography and video. It is shown that with growth and condensation of vapor bubbles, on the liquid film interface appear large-amplitude waves that lead to considerably increasing local intensity of heat transfer. New data on the boiling incipience temperature in a subcooled liquid film, depending on the heat flux density, are obtained. It is found that the development of boiling crisis is a result of appearance of local dry patches and their subsequent growth by the mechanism of longitudinal thermal conductivity in the heat transfer wall as the equilibrium heat flux density is exceeded \\\\expert2\\NBO\\Journal of Engineering Thermophysics\\2013, V.22, N 3. P. 174-193.pdf |
T 44 The visualization of boiling-up onset of superheated n-pentane in a glass capillary at atmospheric pressure by high-speed video [Electronic resource] / E. V. Lipnyagov, M. A. Parshakova, S. A. Perminov, G. V. Ermakov // International Journal of Heat and Mass Transfer. - 2013. - Vol.60, №1. - P612-615. - Bibliogr. : p. 615 (12 ref.) Рубрики: ФИЗИКА Кл.слова (ненормированные): BOILING-UP -- BUBBLES -- HIGH-SPEED VIDEO Аннотация: Experimental study of boiling-up of superheated n-pentane at atmospheric pressure in a glass capillary was carried out by high-speed video. From a visual comparison of video frames, we consider the character of vaporization in three temperature ranges corresponding to the following areas of the temperature dependence of the mean lifetime of metastable state: low temperature descending section, "plateau", and boundary of attainable superheat. Temperature at the boundary of attainable superheat was about 2 °C lower than the maximum values reported in the literature and achieved in the more narrow capillaries and 2.5 °C lower than at the homogeneous boundary of attainable superheat \\\\expert2\\NBO\\International Journal of Heat and Mass Transfer\\2013, v.60, p.612-615.pdf |
D 63 Disintegration of flows of superheated liquid films and jets [Электронный ресурс] / A. N. Pavlenko, A. S. Surtaev, A. N. Tsoi, V. P. Koverda, A. V. Reshetnikov, N. A. Mazheiko, K. A. Busov, V. N. Skokov // Journal of Engineering Thermophysics. - 2013. - Vol.22, №3. - С. 174-193. - Библиогр.: с. 190-193 (65 ref.) Рубрики: ФИЗИКА Кл.слова (ненормированные): SUPERHEATED LIQUID FILMS -- LIQUID BOILING -- JET SHAPE Аннотация: This paper represents results on investigating the dynamics of boiling and disintegration of superheated liquid films and jets. The first part deals with experimental study of boiling liquid outflow through short cylindrical and slit channels. Evolution of disintegration of a hot water jet flow is observed both at low and moderate superheating and at high and limit superheating, and also for vaporization mechanisms corresponding to these superheatings. Peculiarities of disintegration of jets through slit and cylindrical channels are noticed. Results on measuring the reactive thrust of the jet through a slit channel under different geometrical conditions behind the channel outlet are represented. The 1/f fluctuations in transient regimes of superheated liquid boiling and in transient regimes of behavior of the jet shape are found. The second part of this article represents results on experimental investigation of nonsteady heat transfer and dynamics of the development of crisis phenomena at boiling of a falling subcooled liquid film in the conditions of stepwise heat release. The experimental data were obtained using synchronized high-speed infrared thermography and video. It is shown that with growth and condensation of vapor bubbles, on the liquid film interface appear large-amplitude waves that lead to considerably increasing local intensity of heat transfer. New data on the boiling incipience temperature in a subcooled liquid film, depending on the heat flux density, are obtained. It is found that the development of boiling crisis is a result of appearance of local dry patches and their subsequent growth by the mechanism of longitudinal thermal conductivity in the heat transfer wall as the equilibrium heat flux density is exceeded. \\\\expert2\\NBO\\Journal of Engineering Thermophysics\\2013, V.22, N 3. P. 174-193.pdf |
V 28 Vapor Pressures, Enthalpies of Vaporization, and Critical Parameters of a Series of Linear Aliphatic Dimethyl Esters of Dicarboxylic Acids [Текст] / S. P. Verevkin, S. A. Kozlova, V. N. Emel'yanenko, E. D. Nikitin, A. P. Popov, E. L. Krasnykh // Journal of Chemical & Engineering Data. - 2006. - Vol. 51, № 5. - С. 1896-1905 Рубрики: ФИЗИКА Кл.слова (ненормированные): VAPOR PRESSURES Аннотация: Vapor pressures and the molar enthalpies of vaporization of the linear aliphatic dimethyl esters of dicarboxylic acids CH3-CO2-(CH2)n-CO2-CH3 with n = (0 to 8) have been determined by the transpiration method. A linear correlation of enthalpies of vaporization (at T = 298.15 K) of the esters studied with the number n and with the Kovat's indices and has been found. The critical temperatures and pressures of the esters with n = (0 to 6) and n = 8 have been measured by the pulse-heating method with the residence times ranging from (0.03 to 1) ms. Experimental data on the critical properties are compared with the estimations by group contribution methods by Constantinou and Gani and by Marrero and Gani. Both methods considerably underestimate the critical temperatures of the esters studied; however, the method by Marrero and Gani provides the prediction of the critical pressures of the esters with an average absolute error approximately equal to the uncertainty of the measurements. ?? \\\\Expert2\\NBO\\Journal of Chemical and Engineering Data\\2006, v.51, p.1896.pdf |
P 34 Pavlov, P. A. Vaporization in Polymer Liquids under Conditions of Rapid Heating [] / P. A. Pavlov, P. V. Skripov // High Temperature. - 1998. - V.36, N3. - С. 448-455 Рубрики: ФИЗИКА Кл.слова (ненормированные): VAPORIZATION -- LIQUID POLYMER -- HEATING RAPID -- POLYMER |
F 17 Faizullin, M. Z. New universal relationships for surface tension and vaporization enthalpy of non-associated liquids / M. Z. Faizullin // Fluid Phase Equilibria. - 2003. - Vol.211, №1. - С. 75-83 Рубрики: ФИЗИКА Кл.слова (ненормированные): VAPOR-LIQUID -- METHOD OF CALCULATION -- ENTHALPY OF VAPORIZATION Аннотация: The methodology of thermodynamic similarity has been used to study the relation between the surface tension of a liquid and the vaporization enthalpy calculated per unit volume of the liquid phase. Simple reliable relationships that do not contain substance dependent parameters have been found. A new universal one-parameter relationship for the temperature dependence of the vaporization enthalpy has been suggested. The results of calculations with the use of these relationships are compared with experimental data |
P 34 Pavlov, P. A. Thermodynamic crisis of boiling / P. A. Pavlov // Journal of Engineering Thermophysics. - 2007. - Vol.16, №3. - С. 145-154 Рубрики: ФИЗИКА Кл.слова (ненормированные): VAPOR -- LOOP HEAT PIPE Аннотация: The procedure of calculation of the dynamics of rapid near-wall vaporization near a metallic heater is considered. A physical model of explosive boiling-up on bubbles of fluctuation origin is used. The model is limited to regimes when the motion of bubbles can be ignored and convective flows do not have enough time to develop. It is assumed that the dry spot under a bubble thermally insulates the heater wall. The heat removal is provided by the vicinity of the wetting line (WL). An analytical calculation has become possible on the basis of the well-known exact solution to the problem of the temperature field near the wetting line. Generalization of this solution has led to two new problems. These are the problem of allowance for the difference of the dynamic wetting angle from the right angle and that of allowance for thermocapillary flows. A numerical comparison of the results of calculation of the dry area with the use of different methods of allowing for the “tightness” effect in the dynamics of bubble generation and growth has been made. The evolution of bubbles from their generation to growth limited by the heat supply has been investigated. It has been found that the transition stage in the development of bubbles from Rayleigh to thermal ones is of considerable importance in the processes of explosive boiling-up. The dynamics of change in the dry area and wetting line length prior to the stage of bubble merging into a vapor film has been calculated. A condition of passage of the heat flux through a maximum is found. The applicability of the idea of thermodynamic crisis to calculations of miniature devices is justified. The problem of constructing a model to calculate the interphase surface shape near the wetting line under a developed thermocapillary flow and considerable reactive forces of the vapor flow is formulated. The model is in good agreement with the results of experiments on pulsed superheating of liquids at a rate higher than 1 K/μs |
T 82 Transient behavior of superheated water jets boiling [Электронный ресурс] / A. V. Reshetnikov, K. A. Busov, N. A. Mazheiko, V. N. Skokov, V. P. Koverda // Thermophysics and Aeromtchanics. - 2012. - Vol.19, №2. - P329-336 Рубрики: ФИЗИКА Кл.слова (ненормированные): 1/f FLUCTUATIONS -- JET FORMS -- NUCLEATION FREQUENCY Аннотация: Superheated water flowing out from high-pressure chamber through short cylindrical and slot channel has been studied experimentally. Relation of vaporization mechanisms in superheated liquid (boiling in single, not interacting centers, intense heterogeneous vaporization, and homogeneous fluctuating nucleation) and respective forms of superheated water jets has been determined. Temperature intervals with transient behavior of boiling have been determined. It is shown that at transient behavior of boiling the amplitude of pulsations of jet parameters increases, and in the spectra of pulsation power, the low-frequency component 1/f appears |
P 34 Pavlov, P. A. Dynamics of vapor film formation upon rapid superheating of liquid [Electronic resource] / P. A. Pavlov, V. E. Vinogradov // High Temperature. - 2010. - Vol.48, №5. - P683-690. - Bibliogr. : p. 690 (18 ref.) Рубрики: ФИЗИКА Кл.слова (ненормированные): VAPOR FILM -- SUPERHEATING OF LIQUID -- DYNAMICS Аннотация: The formation of a vapor film on a heater in the modes of rapid near-wall superheating of liquid at positive and negative pressures is considered. A model of this phenomenon and a technique for calculating the vaporization front velocity are proposed. Tests of this model in experiments with n-heptane at pressures from −2 to +0.2 MPa and heating rates of ∼0.5 K/μs showed a significant effect of capillary forces on the dynamics of vapor film form \\\\expert2\\NBO\\High Temperature\\2010, v. 48, N 5, p.683.pdf |
D 63 Disintegration of flows of superheated liquid films and jets [Electronic resource] / A. N. Pavlenko, V. P. Koverda, A. V. Reshetnikov, A. S. Surtaev, A. N. Tsoi, N. A. Mazheiko, K. A. Busov, V. N. Skokov // Journal of Engineering Thermophysics. - Bibliogr. : p. 192-193 (65 ref.) Рубрики: ФИЗИКА Кл.слова (ненормированные): CYLINDRICAL CHANNEL -- EXPERIMENTAL INVESTIGATIONs -- BOILING INCIPIENCE Аннотация: This paper represents results on investigating the dynamics of boiling and disintegration of superheated liquid films and jets. The first part deals with experimental study of boiling liquid outflow through short cylindrical and slit channels. Evolution of disintegration of a hot water jet flow is observed both at low and moderate superheating and at high and limit superheating, and also for vaporization mechanisms corresponding to these superheatings. Peculiarities of disintegration of jets through slit and cylindrical channels are noticed. Results on measuring the reactive thrust of the jet through a slit channel under different geometrical conditions behind the channel outlet are represented. The 1/f fluctuations in transient regimes of superheated liquid boiling and in transient regimes of behavior of the jet shape are found. The second part of this article represents results on experimental investigation of nonsteady heat transfer and dynamics of the development of crisis phenomena at boiling of a falling subcooled liquid film in the conditions of stepwise heat release. The experimental data were obtained using synchronized high-speed infrared thermography and video. It is shown that with growth and condensation of vapor bubbles, on the liquid film interface appear large-amplitude waves that lead to considerably increasing local intensity of heat transfer. New data on the boiling incipience temperature in a subcooled liquid film, depending on the heat flux density, are obtained. It is found that the development of boiling crisis is a result of appearance of local dry patches and their subsequent growth by the mechanism of longitudinal thermal conductivity in the heat transfer wall as the equilibrium heat flux density is exceeded \\\\expert2\\NBO\\Journal of Engineering Thermophysics\\2013, V.22, N 3. P. 174-193.pdf |
T 44 The visualization of boiling-up onset of superheated n-pentane in a glass capillary at atmospheric pressure by high-speed video [Electronic resource] / E. V. Lipnyagov, M. A. Parshakova, S. A. Perminov, G. V. Ermakov // International Journal of Heat and Mass Transfer. - 2013. - Vol.60, №1. - P612-615. - Bibliogr. : p. 615 (12 ref.) Рубрики: ФИЗИКА Кл.слова (ненормированные): BOILING-UP -- BUBBLES -- HIGH-SPEED VIDEO Аннотация: Experimental study of boiling-up of superheated n-pentane at atmospheric pressure in a glass capillary was carried out by high-speed video. From a visual comparison of video frames, we consider the character of vaporization in three temperature ranges corresponding to the following areas of the temperature dependence of the mean lifetime of metastable state: low temperature descending section, "plateau", and boundary of attainable superheat. Temperature at the boundary of attainable superheat was about 2 °C lower than the maximum values reported in the literature and achieved in the more narrow capillaries and 2.5 °C lower than at the homogeneous boundary of attainable superheat \\\\expert2\\NBO\\International Journal of Heat and Mass Transfer\\2013, v.60, p.612-615.pdf |
D 63 Disintegration of flows of superheated liquid films and jets [Электронный ресурс] / A. N. Pavlenko, A. S. Surtaev, A. N. Tsoi, V. P. Koverda, A. V. Reshetnikov, N. A. Mazheiko, K. A. Busov, V. N. Skokov // Journal of Engineering Thermophysics. - 2013. - Vol.22, №3. - С. 174-193. - Библиогр.: с. 190-193 (65 ref.) Рубрики: ФИЗИКА Кл.слова (ненормированные): SUPERHEATED LIQUID FILMS -- LIQUID BOILING -- JET SHAPE Аннотация: This paper represents results on investigating the dynamics of boiling and disintegration of superheated liquid films and jets. The first part deals with experimental study of boiling liquid outflow through short cylindrical and slit channels. Evolution of disintegration of a hot water jet flow is observed both at low and moderate superheating and at high and limit superheating, and also for vaporization mechanisms corresponding to these superheatings. Peculiarities of disintegration of jets through slit and cylindrical channels are noticed. Results on measuring the reactive thrust of the jet through a slit channel under different geometrical conditions behind the channel outlet are represented. The 1/f fluctuations in transient regimes of superheated liquid boiling and in transient regimes of behavior of the jet shape are found. The second part of this article represents results on experimental investigation of nonsteady heat transfer and dynamics of the development of crisis phenomena at boiling of a falling subcooled liquid film in the conditions of stepwise heat release. The experimental data were obtained using synchronized high-speed infrared thermography and video. It is shown that with growth and condensation of vapor bubbles, on the liquid film interface appear large-amplitude waves that lead to considerably increasing local intensity of heat transfer. New data on the boiling incipience temperature in a subcooled liquid film, depending on the heat flux density, are obtained. It is found that the development of boiling crisis is a result of appearance of local dry patches and their subsequent growth by the mechanism of longitudinal thermal conductivity in the heat transfer wall as the equilibrium heat flux density is exceeded. \\\\expert2\\NBO\\Journal of Engineering Thermophysics\\2013, V.22, N 3. P. 174-193.pdf |