B 16 Baidakov, V. G. Surface tension of helium-oxygen and helium-ethane solutions [Text] / V. G. Baidakov, I. I. Sulla // International Journal of Thermophysics. - 1995. - V. 16, N 4. - P909-927 Рубрики: ФИЗИКА Кл.слова (ненормированные): НАТЯЖЕНИЕ ПОВЕРХНОСТНОЕ -- ПОВЕРХНОСТНОЕ НАТЯЖЕНИЕ -- РАСТВОРЫ -- ГЕЛИЙ-КИСЛОРОД -- ГЕЛИЙ-ЭТАН -- ГЕЛИЙ -- He (ГЕЛИЙ) -- КИСЛОРОД -- O (КИСЛОРОД) -- ЭТАН -- C2H6 -- ГАЗЫ -- зависимости температурные -- ТЕМПЕРАТУРНАЯ ЗАВИСИМОСТЬ -- ДАВЛЕНИЕ -- ТЕПЛОФИЗИКА Аннотация: На основе измерений высоты подъема в капиллярных трубках насыщенных газом растворов He-O2 и He-C2H6 определены их константы капиллярности а и поверхностное натяжение сигма. Измерения проведены в диапазоне от температуры замерзания раствора до 0,9Тс (Тс-критическая температура растворителя) при давлениях от давления насыщения до 5 МПа. предложены формулы, аппроксимирующие зависимости а от p и сигма от концепции. Полученные данные описываются теорией поверхностного слоя конечной толщины, мономолекулярное приближение не удовлетворительно даже ниже нормальной температуры кипения \\EXPERT2\NBO\International Journal of Thermophysics\1995, V.16, N 4, p.909.pdf |
B 93 Bulanov, N. V. Characteristic features of the boiling of emulsions having a low-boiling dispersed phase [Electronic resource] / N. V. Bulanov, B. M. Gasanov // Journal of Engineering Physics and Thermophysics. - 2006. - Vol. 79, № 6. - P1130-1133 Рубрики: ФИЗИКА Кл.слова (ненормированные): BOILING Аннотация: The results of investigation of heat transfer from thin wires to a boiling emulsion, the dispersed phase of which is formed from a liquid with a boiling temperature much lower than the boiling temperature of the dispersion medium, are presented. Two variants of boiling of such an emulsion are possible: boiling of the dispersed phase alone and simultaneous boiling of the dispersed phase and dispersion medium. In the present work, only the first variant has been studied; it is distinguished by the following most important features: high superheat of the dispersed-phase droplets ?Tsup of the emulsion and a wide temperature range of bubble boiling (50–200°C). For conventional heat carriers (pure liquids and solutions), the value of ?Tsup does not exceed 1–10°C, with the bubble-boiling interval lying within the range from 5 to 20°C. \\\\Expert2\\NBO\\Journal of Engineering Physics and Thermophysics\\2006, v.79, N 6, P.1130.pdf |
R 30 Reaktive Recoil and Pressure Pulsations with 1/f Power Spectrum under Conditions of Explosion Boiling of Jets of Superheated Liquid [] / A. V. Reshetnikov, N. A. Mazheiko, V. P. Skripov, V. N. Skokov, V. P. Koverda // High Temperature. - 2002. - V. 40, N 5. - 701-705: graph. - Bibliogr.: p. 760 (14 n.) . - ISSN 0040-3644 Рубрики: ФИЗИКА Кл.слова (ненормированные): THERMOPHYSICS -- REACTIVE RECOIL -- PRESSURE PULSATIONS -- 1/f POWER SPECTRUM -- SUPERHEATED LIQUIDS \\\\Expert2\\NBO\\High Temperature\\2002, v.40, p.701.pdf |
S 66 Skripov, V. P. New Universal Relations for Liquid-Vapor Phase Equilibrium / V. P. Skripov, M. Z. Faizullin // International Journal of Thermophysics. - 2000. - Vol. 21, № 5. - С. 1213-1222 Рубрики: ФИЗИКА Кл.слова (ненормированные): HEAT OF EVAPORATION -- ORTHOBARIC DENSITIES -- SATURATION PRESSURE -- UNIVERSAL RELATION Аннотация: Universal relations between the saturation pressure p LV and the value of =h LV/ LV–p LV, where h LV .is the latent heat of evaporation and LV is the volume change of the vapor-liquid transition, and the product of the orthobaric densities L and V of the liquid and vapor at coexistence have been discovered. In the temperature range from the triple point to T/T c0.9, these relations obey a power law with universal exponents. At temperatures 0.9T/T c1, p LV and depend linearly on ln( LV) with retention of universality for substances of different nature \\\\Expert2\\NBO\\International Journal of Thermophysics\\2000, v.21, N 5, p.1213.pdf |
S 66 Skripov, P. V. The phenomenon of superheat of liquids: in memory of Vladimir P. Skripov / P. V. Skripov, V. P. Skripov // International Journal of Thermophysics. - 2010. - Vol. 31, № 4-5. - С. 816-830 : рис., фото. - Bibliogr. : p. 829-830 (35 ref.) Рубрики: ФИЗИКА Кл.слова (ненормированные): EXPERIMENTAL METHODS -- PROPERTIES THERMOPHYSICAL -- LIQUIDS \\\\Expert2\\NBO\\International Journal of Thermophysics\\2010, v.31, N 4-5, p.816.pdf |
H 65 High heat flux loop heat pipes / M. T. North, D. B. Sarraf, J. H. Rosenfeld, Yu. F. Maydanik, S. V. Vershinin // SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM (STAIF-97), PTS 1-3: 1ST CONFERENCE ON FUTURE SCIENCE & EARTH SCIENCE MISSIONS; 1ST CONFERENCE ON SYNERGISTIC POWER & PROPULSION SYSTEMS TECHNOLOGY; 1ST CONFERENCE ON APPLICATIONS OF THERMOPHYSICS IN MICROGRAVITY; 2ND CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; - 2ND CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 14TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION, ALBUQUERQUE, 26-30 JAN, 1997 . - 1997. - Vol.387. - С. 561-566 Рубрики: ФИЗИКА Кл.слова (ненормированные): LOOP HEAT PIPES -- THERMAL POWER LOADS -- VAPOR FLOW LOSSES Аннотация: Loop Heat Pipes (LHPs) can transport very large thermal power loads, over long distances, through flexible, small diameter tubes and against high gravitational heads. While recent LHPs have transported as much as 1500 W, the peak heat flux through a LHP's evaporator has been limited to about 0.07 MW/m(2). This limitation is due to the arrangement of vapor passages next to the heat load which is one of the conditions necessary to ensure self priming of the device. This paper describes work aimed at raising this limit by threefold to tenfold. Two approaches were pursued. One optimized the vapor passage geometry for the high heat flux conditions. The geometry improved the heat flow into the wick and working fluid. This approach also employed a finer pored wick to support higher vapor flow losses. The second approach used a bidisperse wick material within the circumferential vapor passages. The bidisperse material increased the thermal conductivity and the evaporative surface area in the region of highest heat flux, while providing a flow path for the vapor. Proof-of-concept devices were fabricated and tested for each approach. Both devices operated as designed and both demonstrated operation at a heat flux of 0.70 MW/m(2). This performance exceeded the known state of the art by a factor of more than six for both conventional heat pipes and for loop heat pipes using ammonia. In addition, the bidisperse-wick device demonstrated boiling heat transfer coefficients up to 100,000 W/m(2) K, and the fine pored device demonstrated an orientation independence with its performance essentially unaffected by whether its evaporator was positioned above, below or level with the condenser |
B 16 Baidakov, V. G. Boiling-up of liquid argon at high superheatings under the impact of weak ultrasonic fields / V. G. Baidakov, A. M. Kaverin, V. N. Andbaeva // Thermophysics and Aeromtchanics. - 2011. - Vol.18, №1. - С. 31-36 Рубрики: ФИЗИКА Кл.слова (ненормированные): NUCLEATION -- KRYPTON Аннотация: The technique of lifetime measurement for metastable liquid and continuous depressurization technique were applied for study of kinetics of spontaneous cavitation in superheated liquid argon under impact of weak ultrasonic fields. It was demonstrated that acoustic cavitation may occur through the mechanism of homogeneous generation of vapor phase or through "swinging" of vapor bubbles generated by high-energy particles and/or other kinds of initiative factors. The thresholds of acoustic cavitation are described by the theory of homogeneous nucleation |
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. Metastable phase equilibria in a Lennard-Jones system / V. G. Baidakov, S. P. Protsenko // Journal of Engineering Thermophysics. - 2007. - Vol.16, №4. - С. 249-258 Рубрики: ФИЗИКА Кл.слова (ненормированные): METHOD MOLECULAR DYNAMICS -- INTERNAL ENERGY -- LENNARD-JONES Аннотация: A method of molecular dynamics is used to calculate the pressure, internal energy, and isochoric heat capacity in a system of 2048 Lennard-Jones particles in the range of reduced temperatures from 0.1 to 2.0 and the range of densities from 0.001 to 1.15. Local equations of state for the gas, liquid, and crystalline phases are derived. The spinodals of a superheated (extended) liquid, supersaturated vapor, and superheated (extended) crystal are determined. It is shown that the spinodal of a supercooled liquid is nonexistent. An algorithm to calculate the lines of phase equilibria is constructed. The lines of liquid-gas, liquid-crystal, crystal-gas phase equilibria, and their metastable extensions are determined. It is shown that the metastable extensions of the melting and sublimation lines terminate at the spinodals of the liquid and crystal, respectively. The properties of final critical points in the lines of melting and sublimation are considered |
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 |
I-34 Identification of heat-exchange parameters under intensive pulse heating of a wire in a fluid / V. I. Gorbatov, Yu. S. Okulovskii, P. V. Skripov, A. A. Smotritskiy, A. A. Starostin // Journal of Engineering Thermophysics. - 2010. - Vol.19, №3. - С. 144-153 Рубрики: ФИЗИКА Кл.слова (ненормированные): HEAT EXCHANGE -- FLUID |
N 64 Nikitin, E. D. Temperatures of the Attainable Superheat of Some Thermally Unstable Liquids / E. D. Nikitin, P. A. Pavlov, A. P. Popov // International Journal of Thermophysics. - 2002. - Vol.23, №2. - С. 529-541 Рубрики: ФИЗИКА Кл.слова (ненормированные): HOMOGENEOUS NUCLEATION -- KINETIC PARAMETERS -- WIRE PROBE Аннотация: The paper gives the results of measuring the temperatures of the attainable superheat of some liquids that are thermally unstable at these temperatures. The technique of heating a thin wire probe placed into a liquid under study with electric-current pulses has been used. The length of pulses is from 10–5 to 10–3 s, which corresponds to a heating rate of 105 to 108 K·s–1. The influence of a chemical reaction in the liquid phase on the temperature of the attainable superheat has been considered. In particular, it has been shown that boiling initiated by an elementary act of an exothermic chemical reaction is of a low probability. A method of calculating the temperature of the attainable superheat of thermally unstable liquids under conditions of quick heating has been developed. A method for the determination of the kinetic parameters of thermal decomposition from the measurements of the temperature of the attainable superheat is discussed |
P 34 Pavlov, P. A. Heat transfer under the conditions of near-wall explosive boiling-up / P. A. Pavlov // Journal of Engineering Thermophysics. - 2003. - Vol.12, №1. - С. 25-38 Рубрики: ФИЗИКА Кл.слова (ненормированные): BOILING-UP -- FLUCTUATION -- HEAT TRAHSFER |
V 70 Vinogradov, V. E. Cavitation strength of water solutions / V. E. Vinogradov, P. A. Pavlov // Journal of Engineering Thermophysics. - 2003. - Vol.11, №4. - С. 353-363 Рубрики: ФИЗИКА Кл.слова (ненормированные): FLUID CONDITION -- CAVITATION -- WATER |
B 93 Bulanov, N. V. Peculiarities of boiling of emulsions with a low-boiling dispersed phase / N. V. Bulanov, B. M. Gasanov, V. A. Khmylnin // Journal of Engineering Thermophysics. - 2007. - Vol.16, №4. - С. 224-230 Рубрики: ФИЗИКА Кл.слова (ненормированные): HEAT TRAHSFER -- LOW TEMPERATURES -- BOILING Аннотация: The results of an investigation of heat transfer from thin wires to emulsions whose dispersed phase is low-boiling in comparison with its dispersion medium are presented. A peculiarity of heat transfer with such emulsions is observed in the bubble boiling regime when only droplets of the emulsion dispersed phase are boiling. Theoretical and experimental investigations of the activation mechanism of boiling centers have been performed. The critical volume V 0 of the emulsion, with chain nucleation taking place when this volume is exceeded, has been determined. A model of chain activation of low-temperature boiling centers has been developed. The model has been qualitatively confirmed by the experimental data obtained |
K 79 Koverda, V. P. Statistics of low-frequency pulsations in critical regimes of heat mass exchange with phase transitions / V. P. Koverda, V. N. Skokov, A. V. Reshetnikov // Journal of Engineering Thermophysics. - 2007. - Vol.16, №3. - С. 130 -138 Рубрики: ФИЗИКА Кл.слова (ненормированные): FLUCTUATION -- IRREGULAR HIGH-ENERGY -- 1 / F СПЕКТРЫ Аннотация: Experimental investigation of fluctuation dynamics in critical and transitional modes of heat mass exchange shows existence of irregular high-energy pulsations with power spectrum inversely proportional to the frequency—so called 1/f spectrum. Such regimes are characterized by the fact that an essential part of the pulsations energy is connected with very slow processes and mean that large high-energy bursts are possible in the system. Another characteristic feature of such regimes is scale invariance of the fluctuations distribution function. According to the theory, the 1/f fluctuations can emerge in physical systems due to simultaneous phase transitions in presence of sufficiently intensive white noise. This paper is devoted to detailed investigation of relaxation processes at steadying of stationary stochastic process in non-equilibrium phase transitions in system of two nonlinear stochastic differential equation. Such an information reveals statistical patterns of particular large-scale low-frequency bursts. Discontinuous “forgetting” of the initial conditions takes place. It is shown by numerical methods that distributions of duration and maximal values of the low-frequency extreme bursts have the power-like form. Experimental investigation results of statistical characteristics of fluctuation processes at ultrasonic cavitation and flash boiling of overheated water jets are presented. Results of the experiments carried out fit conclusions of the theoretical model for interacting heterogeneous phase transitions |
F 17 Faizullin, M. Z. On the law of corresponding states for thermodynamic properties of a crystal / M. Z. Faizullin // Journal of Engineering Thermophysics. - 2007. - Vol.16, №3. - С. 139-144 Рубрики: ФИЗИКА Кл.слова (ненормированные): THERMODYNAMIC SIMILARITY -- CRYSTALLINE SUBSTANCES -- METASTABLE SYSTEMS Аннотация: To study thermodynamic similarity of the properties of crystalline substances, we propose an approach connected with engaging of the metastable state region. Internal pressure and specific volume on the crystal’s stability boundary at T = 0 K are used as characteristic scales of thermodynamic variables. A semiempirical method of calculation of the stability boundary by the thermodynamic data related to the stable states region of a solid body is described. In the cases of argon and natrium, the stability boundary is calculated for a wide range of temperatures and pressures. Analysis of the properties of neon, argon, krypton, and xenon crystals in these variables indicates that the law of corresponding states holds for these substances |
B 73 Boiling up of jets of superheated ethanol-water solutions / A. V. Reshetnikov, A. V. Vinogradov, V. N. Begletsov, V. N. Skokov, V. P. Koverda // Journal of Engineering Thermophysics. - 2007. - Vol.16, №4. - С. 244-248 Рубрики: ФИЗИКА Кл.слова (ненормированные): EVOLUTION OF THE SHAPES -- SUPERHEATED AQUEOUS SOLUTIONS -- LOW-BOILING LIQUID Аннотация: The stability and evolution of the shapes of jets of strongly superheated aqueous solutions of ethanol flowing out of a high-pressure chamber are experimentally investigated at various initial parameters. It has been found that a low-boiling liquid causes shifting to lower temperatures of the boundaries between various kinds of boiling-up jets, such as cylindrical, conical, and open. Large-scale pulsations of the jet shapes are observed in the temperature range from 454 to 484 K, where the jet completely breaks down. The conditions for the formation of large-scale low-frequency pulsations with a power spectrum diverging inversely proportional to the frequency f (1/f spectra) have been revealed. Such fluctuations prove that the flow is unstable and large-scale low-frequency ejections are possible |
N 64 Nikitin, E. D. Using the phenomenon of liquid superheat to measure critical properties of substances / E. D. Nikitin, A. P. Popov // Journal of Engineering Thermophysics. - 2007. - Vol.16, №3. - С. 200-204 Рубрики: ФИЗИКА Кл.слова (ненормированные): CRITICAL TEMPERATURES -- R1(CH2)nR2 Аннотация: A method to measure the critical temperature and critical pressure of substances, in particular, thermally unstable ones, is briefly described. The method is used to measure the temperature of attainable superheat of liquids with the help of a wire probe heated by electric current pulses. As the pressure increases, the temperature of attainable superheat tends to a critical temperature. The duration of the heating pulses is from 0.03 to 1 ms. A list of about 130 substances for which measurements of the critical properties were made is presented. The results of these measurements confirmed the scaling form of the relation between the critical constants of substances consisting of long chain molecules and the number of molecular units. Two methods to extrapolate the experimental data for the critical properties of the initial members of homologous series to heavier polymer homologs are proposed. One of the methods is based on the equation of state for the fluid of chain molecules. In this method, the extrapolating equations are power series in n, where n is the number of main units in a chain molecule. In the other method, the hypothesis of functional self-similarity and the presentation of scaling behavior of the critical constants of long chain molecules are used. Homologous series with the general formula R1 (CH2)nR2, where R1 and R2 are different end groups, are considered. We obtain equations to calculate, with good accuracy, the critical temperature and critical pressure of any member of any homologous series with the molecule structure R1(CH2)nR2 if they are known for one compound belonging to this series |
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 |