B 16 Baidakov, V. G. Maximum superheating of liquid-oxygen in metal nucleus [Text] / V. G. Baidakov // High Temperature. - 1985. - V.23, N1. - P124-130 Рубрики: ФИЗИКА Кл.слова (ненормированные): ПЕРЕГРЕВ КИСЛОРОДА -- КИСЛОРОД ЖИДКИЙ -- КИСЛОРОД -- O (КИСЛОРОД) -- ЗАРОДЫШИ МЕТАЛЛИЧЕСКИЕ -- ПЕРЕГРЕВ МАКСИМАЛЬНЫЙ |
Б 18 Байдаков, В. Г. Достижимый перегрев жидких растворов гелий-кислород [] = Attainable Superheating of Helium-Oxygen Solutions / В. Г. Байдаков, А. М. Каверин // Теплофизика высоких температур. - 2000. - Т. 38, N6. - С. 886-894 Рубрики: ФИЗИКА Кл.слова (ненормированные): O2 -- He2 -- КИСЛОРОД -- ГЕЛИЙ -- ГЕЛИЙ-КИСЛОРОД -- ПЕРЕГРЕВ -- ПЕРЕГРЕВ ДОСТИЖИМЫЙ -- РАСТВОРЫ -- РАСТВОРЫ ЖИДКИЕ -- ЗАРОДЫШЕОБРАЗОВАНИЕ -- КИНЕТИКА ЗАРОДЫШЕОБРАЗОВАНИЯ -- РАСТВОРЫ ГАЗОНАСЫЩЕННЫЕ -- ДАВЛЕНИЕ -- КОНЦЕНТРАЦИЯ РАСТВОРА -- ЗАВИСИМОСТИ ТЕМПЕРАТУРНЫЕ -- ВРЕМЯ ЖИЗНИ РАСТВОРА -- СОСТОЯНИЕ МЕТАСТАБИЛЬНОЕ -- СОСТОЯНИЕ ПЕРЕГРЕТОЕ -- НУКЛЕАЦИЯ ГОМОГЕННАЯ -- РАЗМЕР ЗАРОДЫШЕЙ Аннотация: Представлены результаты экспериментальных исследований кинетики зародышеобразования в газонасыщенных растворах гелий-кислород. При фиксированных давлениях 1.171 и 1.667 МПа и нескольких значениях концентрации определены температурные зависимости среднего времени жизни раствора в метастабильном (перегретом) состоянии. Экспериментальные данные сопоставляются с теорией гомогенной нуклеации в макроскопическом приближении с учетом зависимости свойств зародышей от их размера |
S 66 Skripov, V. P. Attainable Superheating and Explosive Boiling-Up of Liquids [Text] / V. P. Skripov // Hemisphere Publishing Corporation: International seminar on turbulent natural convention (Dubrovnik, Yugoslavia, 30 Aug. - 4 Sept. 1976). - 1976. - P601-614 Рубрики: ФИЗИКА Кл.слова (ненормированные): СЕМИНАРЫ -- ДОКЛАДЫ -- ПЕРЕГРЕВ ЖИДКОСТЕЙ -- ЖИДКОСТИ (ТЕПЛОФИЗИКА) -- КИПЕНИЕ ВЗРЫВНОЕ -- ВЗРЫВНОЕ КИПЕНИЕ -- ПЕРЕГРЕВ ДОСТИЖИМЫЙ -- ДОСТИЖИМЫЙ ПЕРЕГРЕВ -- ТЕПЛОФИЗИКА |
G 95 Gurashkin, A. L Experimental study of the kinetics of boiling and superheating boundary of n-hexane in rigid powder structures [Текст] / A. L Gurashkin, S. A. Perminov, G. V. Ermakov // Teplofizika i Aeromekhanika. - 2006. - Vol. 13, № 4. - С. 641-650 Рубрики: ФИЗИКА Кл.слова (ненормированные): N-HEXANE |
S 24 Saturated superheating of liquid-oxygen in metal nucleus [] / A. M. Kaverin, V. G. Baidakov, V. P. Skripov, A. N. Katyanov // Zhurnal Tekhnicheskoi Fiziki. - 1985. - V.55, Is.6. - С. 1220-1222 Рубрики: ФИЗИКА Кл.слова (ненормированные): SUPERHEATING SATURATED -- LIQUID-OXYGEN -- OXYGEN -- O (КИСЛОРОД) -- NUCLEI METAL |
T 34 Temperature of Attainable Superheating of Some Commercial Petroleum Products [] / E. D. Nikitin, P. A. Pavlov, A. P. Popov // High Temperature. - 2001. - Vol. 39, N 1. - С. 93-96: il. - Bibliogr: p. 100 Рубрики: ФИЗИКА Кл.слова (ненормированные): TEMPERATURE -- TEMPERATURE OF ATTAINABLE SUPERHEATING -- SUPERHEATING -- ATTAINABLE SUPERHEATING -- PETROLEUM PRODUCTS \\\\Expert2\\NBO\\High Temperature\\2001, v.39, p.93.pdf |
B 16 Baidakov, V. G. The attainable superheating of nitrogen-helium solutions [Electronic resource] / V. G. Baidakov // Russian Journal of Physical Chemistry A. - 2009. - Vol.83, №10. - P1751-1756 Рубрики: ФИЗИКА Кл.слова (ненормированные): HOMOGENEOUS NUCLEATION -- OXYGEN -- KRYPTON Аннотация: The nucleation of the vapor phase in superheated nitrogen-helium liquid solutions was studied by lifetime measurements. The temperature dependences of the mean lifetime of metastable solutions were obtained at p = 0.5 and 1.0 MPa and several concentrations. The nucleation rate J was found to vary from 10(4) to 10(8) s(-1) m(-3). The adsorption of the high-volatility component on the metastable liquid-critical bubble boundary was shown to play a determining role in decreasing the temperature of the attainable solution super-heating as the solution concentration increased. The experimental data were compared with homogeneous nucleation theory. Systematic discrepancies were obtained; these discrepancies were related to the influence of the size effect on the surface tension of a nucleus and the work of its formation \\\\Expert2\\nbo\\Russian Journal of Physical Chemistry A, Focus on Chemistry\\2009, v. 83, N 10, p.1751.pdf |
B 16 Baidakov, V. G. Superheating of liquid xenon in metal tubes [Electronic resource] / V. G. Baidakov, A. M. Kaverin // Journal of Chemical Physics. - 2009. - Vol.131, №6. - Artical Number 064708 Рубрики: ФИЗИКА Кл.слова (ненормированные): LINE-TENSION -- SURFACE TENSION -- NUCLEATION Аннотация: The method of measuring the lifetime has been used to investigate the kinetics of spontaneous boiling-up of superheated xenon in copper tubes. In experiments the temperature dependence of the mean lifetime has been determined at pressures of 1.48 and 1.98 MPa. The data obtained have been compared with homogeneous nucleation theory. It has been found that experimental values of the attainable superheating temperature and the derivative (partial derivative ln J/partial derivative T)(p) are systematically lower than their theoretical values. A description of experimental data in the framework of heterogeneous nucleation theory has shown that for the agreement of theory and experiment with the use of a macroscopic model of nucleation on a smooth surface it is necessary to take the value of the equilibrium contact angle theta(0) equal to 70 degrees, which is not a characteristic for a xenon-metal system. Taking into account the contribution of the energy of the three-phase contact solid wall-liquid-gas in a microscopic nucleation model makes it possible to reconcile heterogeneous nucleation theory and experimental data at a contact angle theta(0) close to zero, with the linear tension taken equal to -6x10(-12) J/m and the microscopic contact angle theta(*)similar or equal to 57 degrees. The number of weakened sites, on which bubbles may form, is always smaller than the number of molecules adjacent to the solid wall \\\\Expert2\\nbo\\Journal of Chemical Physics\\2009, v.131, p.064708.pdf |
B 16 Baidakov, V. G. Experimental investigations of superheated and supercooled water (review of papers of the school of the academician V. P. Skripov) / V. G. Baidakov // NATO Science for Peace and Security Series A: Chemistry and Biology. - 2010. - С. 253-270 Рубрики: ФИЗИКА Кл.слова (ненормированные): SOUND VELOCITY -- HEAVY WATER -- SUPERHEATING Аннотация: The review presents the results of experimental investigations of nucleation in superheated light and heavy water in the range of nucleation rates from 104 to 1029 s−1m−3. A study is performed of the kinetics of crystallization of droplets of superheated water and amorphous water layers. Measurements have been made of the density, sound velocity, dielectric constant of light and heavy water in the vicinity of the phase equilibrium line with deep entry into the region of metastable (superheated) states. The local and integral characteristics of streams of boiling-up water flowing out into the atmosphere through a short channel have been investigated. One can see the determining role of a vapor phase in such a process at a temperature above 0.9T c , where T c is the temper-temperature at the critical point |
B 16 Baidakov, V. G. Attainable superheating of solutions of cryogenic liquids / V. G. Baidakov // Journal of Engineering Thermophysics. - 2007. - Vol.16, №3. - С. 109-118 Рубрики: ФИЗИКА Кл.слова (ненормированные): BOILING-UP -- CRYOGENIC LIQUIDS -- KRAMERS-ZELDOVICH METHOD Аннотация: The kinetics of spontaneous boiling-up of superheated binary solutions of cryogenic liquids is studied. Within the framework of the Kramers-Zeldovich method, an expression is obtained for the steady state rate of homogeneous nucleation in a solution that takes into account free-molecular and diffusion regimes of the substance supply to a growing bubble. Viscous and inertial forces are also taken into account in the study of the nucleus growth dynamics. The work of critical nucleus formation is determined within the framework of the Gibbs and van der Waals capillarity theories. The dependence of the surface tension of critical bubbles in the solution on their size is investigated. The temperature of attainable superheating and nucleation rates in superheated solutions of cryogenic liquids with complete or partial solubility of the components are determined by a method of lifetime measurement. The experiments were conducted in a wide range of pressures and solution concentrations. The measurement results are compared with the theory of homogeneous nucleation taking or not taking into account the size effect in nucleation. It has been found that, by taking into account the size dependence of the surface tension of a nucleus, better agreement between the theory and experiment is obtained. The boundary of essential instability of the solution, that is, the diffusion spinodal, is computed |
B 16 Baidakov, V. G. Attainable Superheating of Liquid Helium–Oxygen Solutions / V. G. Baidakov, A. M. Kaverin // High Temperature. - 2000. - Vol.38, №6. - С. 852-859 Рубрики: ФИЗИКА Кл.слова (ненормированные): NUCLEATION -- THEORY OF HOMOGENEOUS NUCLEATION -- BOILING Аннотация: The results are given of experimental investigations of the kinetics of nucleation in gas-saturated helium-oxygen solutions. The temperature dependences of the mean lifetime of solution in the metastable (superheated) state are determined for fixed values of pressure of 1.171 and 1.667 MPa and for several values of concentration. The experimental data are compared with the theory of homogeneous nucleation in a macroscopic approximation with due regard for the dependence of the properties of the nuclei on their size. The dimensional effect is included within van der Waals' gradient expansion. The problems associated with the construction of the kinetic theory of boiling of gas-saturated solutions are discussed, and good agreement is ascertained between the experimental data and the theory of nucleation when the latter includes the dimensional effect |
P 36 Peculiarities of superheated liquid discharging under strong and weak nonequilibrium conditions / A. N. Pavlenko, V. P. Koverda, A. V. Reshetnikov, N. A. Mazheiko, A. S. Surtaev, V. E. Zhukov // Journal of Engineering Thermophysics. - 2010. - Vol.19, №4. - С. 289-305 Рубрики: ФИЗИКА Кл.слова (ненормированные): SUPERHEATED LIQUIDS -- NONEQUILIBRIUM CONDITIONS -- HIGH-PRESSURE CHAMBER Аннотация: Results obtained in experimental investigating the characteristics of superheated liquid jet discharging under different nonequilibrium conditions are presented. The cases of liquid discharge from a high-pressure chamber and under gravitational jet formation conditions are considered. Different mechanisms of liquid flash boiling with heating growing up to limit superheating are identified in the case of liquid discharging from the high-pressure chamber. Dependences of the reactive force and the jet shape on the value of liquid overheating in a flow are presented. It is shown that the rapidly decreasing value of the reactive force of the jet is connected with its complete disintegration caused by homogeneous nucleation and by the presence of a normal wall behind the outlet from the channel. The parameters of two-phase jet stability in the conditions of gravitational falling, the flow rates, and the size of droplet dispersion zones depend substantially on the shape of holes and the heat flux density. Pronounced effects of partial or full blocking of the holes as a result of soluble impurities deposition in the regimes of cryogenic liquid evaporation or boiling when vapor cavities are formed in the channel are observed in the conditions of long-term discharging under nonadiabatic conditions. This leads to complete disintegration of the jet and uncontrollable reduction of the flow rate through the hole up to full blocking of the latter |
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 |
A 10 A method of controlled pulse heating: Applications / P. V. Skripov, A. A. Smotritskiy, A. A. Starostin, A. V. Shishkin // Journal of Engineering Thermophysics. - 2007. - Vol.16, №3. - С. 155-163 Рубрики: ФИЗИКА Кл.слова (ненормированные): THERMOPHYSICAL PROPERTIES -- THERMAL STABILIZATION -- HIGH-MOLECULAR FLUIDS Аннотация: This paper is devoted to the state-of-the-art and technical potentials of the pulse heating method for the thin wire probe created in the Ural thermophysical school for studying the kinetics of spontaneous boiling and the related phenomenon of liquid attainable superheating. Special attention is paid to the search for technical means for controlling the power of the probe heating in a pulse experiment with the thermophysical properties of the substance taken into account. Applications of three particular cases are considered: techniques for the constant heating power, the thermal stabilization of the pulse-heated probe, and cooling of the shock-heated probe for investigating the behavior of multicomponent and high-molecular fluids essentially superheated above the temperature of phase equilibrium and/or temperature of molecule thermodestruction in a quasi-static process. Opportunities for application of the method are presented, in particular, for fast detection of volatile admixtures (including their traces) in high-molecular fluids, e.g., in oils of power equipment |
B 16 Baidakov, V. G. Nucleation in Liquid Ethane with Small Additions of Metha [Electronic resource] / V. G. Baidakov, A. M. Kaverin, A. S. Pankov // Journal of Physical Chemistry C. - 2012. - Vol.116, №38. - P20458-20464 Рубрики: ФИЗИКА Кл.слова (ненормированные): LIQUID -- SPONTANEOUS BOILING-UP -- ETHANE–METHANE SOLUTIONS Аннотация: The method of measuring the lifetime of a liquid in a metastable (superheated) state has been used to investigate the kinetics of spontaneous boiling-up of ethane–methane solutions. The temperature dependence of the solution mean lifetime has been traced at two values of methane concentration (2.1 and 6.0 mol %) and two pressures (1.0 and 1.6 MPa). The results of experiments are compared with classical homogeneous nucleation theory. For pure ethane at small (<8.9 s) lifetimes, one can observe a systematic “under-heating” (0.5–0.7 K) of the solution against theoretical values of the limiting superheating temperature. Dissolution of 6 mol % of methane in ethane results in a solution “superheating” of 0.7 K in excess of the theoretical value. The slopes of experimental curves at small (<8.9 s) lifetimes are in satisfactory agreement with theory. When the mean lifetimes exceed the value of 8.9 s, one can observe considerable deviations of experimental curves from theoretical lines. The discrepancies are discussed in the context of models of heterogeneous and initiated nuc \\\\Expert2\\nbo\\Journal of Physical Chemistry C\\2012, v. 116, p.20458.pdf |
B 16 Baidakov, V. G. Attainable superheating of liquefied gases and their solutions : review [Electronic resource] / V. G. Baidakov // Fizika Nizkikh Temperatur. - 2013. - Vol.39, №8. - P835-862. - Bibliogr. : p. 861-862 (87 ref) Рубрики: ФИЗИКА Кл.слова (ненормированные): CAVITATION -- CRYOGENIC LIQUIDS -- META-STABLE STATE Аннотация: The review is mainly concerned with the kinetics of spontaneous boiling-up of liquefied gases and their solutions. It examines the theories of thermofluctuation and quantum nucleation in metastable liquids. The methods of experimental investigation of nucleation kinetics are given. The experimental data on temperature of attainable superheating of cryogenic liquids and solutions of liquefied gases are presented for a wide range of pressures, including negative ones. The properties of new-phase nuclei near the attainable super-heating boundary are discussed. The kinetics of initiated and heterogeneous nucleation is considered. The experimental data on detection of quantum tunneling of nuclei are given. Experimental data are compared with the theories of thermofluctuation and quantum nucleation |
C 73 Communication: high speed optical investigations of a character of boiling-up onset [Electronic resource] / A. L Gurashkin, A. A. Starostin, G. V. Ermakov, P. V. Skripov // Journal of Chemical Physics. - 2012. - Vol.136, №2. - P021102. - Bibliogr. : p. Рубрики: ФИЗИКА Кл.слова (ненормированные): BOILING -- HEAT TRAHSFER -- MICRO-OPTICS Аннотация: In this communication, we discuss the phenomenon of attainable superheat of liquid and the peculiarities of its release by spontaneous boiling-up. We have combined the apparatus for superheating, namely, bubble chamber, with a high speed micro-optical method for detailed monitoring of the initial stage of boiling-up. In experiments on the isothermal pressure drop, it was found that the boiling-up onset of n-hexane is accompanied by characteristic step signal. The signal has proved to be typical of the heterogeneous character of boiling-up onset in a whole range of superheating degrees. The performance of the method for investigation of the refractive index and density for superheated liquids as functions of temperature and pressure has been revealed. The experimental error is estimated to be 0.1%. \\\\expert2\\NBO\\Journal of Chemical Physics\\2012, V.136, p.021102.pdf |
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 |
E 97 Experimental testing of liquid boiling-up homogeneity near the boundary of the attainable superheating [Electronic resource] / E. V. Lipnyagov, S. A. Perminov, G. V. Ermakov, B. M. Smolyak // Thermophysics and Aeromtchanics. - 2009. - Vol.16, №3. - P445-457. - Bibliogr. : p. 457 (20 ref.) Рубрики: ФИЗИКА Кл.слова (ненормированные): SUPERHEATING -- LIQUID -- N-PENTANE Аннотация: Results of measured average expectancy time of n-pentane and n-hexane boiling-up to the boundary of attainable superheating are presented. Experiments have been carried out in glass capillaries with substantially decreasing value of the superheated liquid volume for the preset metastable state (p, T = const). Obtained data fail to prove correlation 1 JVῑ = following from the condition of homogeneity and stationarity of the random process resulting in the superheated liquid boiling-up (J is the frequency of homogenous nucleation, V is the volume of the superheated liquid, ῑ is the average life time). Thus, experiments on superheated liquid boiling-up kinetics bound with measurements of average life time in glass capillaries cannot serve a proof of the validity of classical theory of nucleation for superheated liquids since one of the ground conditions — boiling-up homogeneity — is not met \\\\expert2\\NBO\\Thermophysics and Aeromechanics\\2009, V. 16, N 3. P. 445-457.pdf |
E 97 Experimental determination of superheated liquids boiling-up expectancy time probabilities distribution [Electronic resource] / E. V. Lipnyagov, S. A. Perminov, G. V. Ermakov, B. M. Smolyak // Thermophysics and Aeromtchanics. - 2009. - Vol.16, №4. - P627-633. - Bibliogr. : p. 633 (16 ref.) Рубрики: ФИЗИКА Кл.слова (ненормированные): LIQUID -- N-PENTANE -- BOILING-UP Аннотация: Results of statistical measurement of n-pentane and n-hexane boiling-up expectancy time near the boundary of attainable superheating are presented. Experiments were carried out in glass capillaries with various volumes of superheated liquid. Several samples with the volume from 100 to 200 measurements of life time for preset metastable state have been obtained (p, T = const). Their histograms contain small empty initial section, maximum and long “tail” in the area of large times. Non-monotonous dependence of probability distribution density on time proves non-stationary character of the random process resulting in the production of supercritical embryo. Two simple approximations of non-stationary nucleation flow well describing experimental data have been considered. For exponential distribution, the probabilities of experimentally found peculiarities of boiling-up expectancy time distribution density have been evaluated; they prove incompatibility of this distribution with the experimental one \\\\expert2\\NBO\\Thermophysics and Aeromechanics\\2009, V. 16, N 4. P. 627-633.pdf |