Б 18 Байдаков, В. Г. Кинетика флуктуационного вскипания перегретого жидкого метана [] = Kinetics of the Fluctuation Ebullition of Superheated Liquid Methane / В. Г. Байдаков, А. М. Каверин, В. П. Скрипов // Коллоидный журнал. - 1980. - Т. 42, N 2. - С. 314-317 Рубрики: ФИЗИКА Кл.слова (ненормированные): МЕТАН ПЕРЕГРЕТЫЙ -- ПЕРЕГРЕТЫЙ МЕТАН -- ВСКИПАНИЕ ФЛУКТУАЦИОННОЕ -- ФЛУКТУАЦИОННОЕ ВСКИПАНИЕ -- КИНЕТИКА ВСКИПАНИЯ -- МЕТАН ЖИДКИЙ -- ЖИДКИЙ МЕТАН |
A 71 Arc current fluctuation power spectra in the system of a solid metal electrode and carbonate melt [Текст] / A. V. Reshetnikov, V. N. Sannikov, V. N. Skokov, V. P. Koverda // Journal of Applied Mechanics and Technical Physics. - 2007. - Vol. 48, № 1. - С. 7-10 Рубрики: ФИЗИКА Кл.слова (ненормированные): SOLID METALS Аннотация: Arc current fluctuations between a solid metal electrode and a liquid melt of alkaline carbonates at atmospheric pressure are measured. Arc current fluctuation power spectra are determined from the measurement data. It is shown that the fluctuation power is inversely proportional to the frequency (1/f-fluctuations). The fluctuations have a normal Gaussian distribution. The observed 1/f fluctuations exhibit scale invariance. \\\\Expert2\\NBO\\Journal of Applied Mechanics and Technical Physics\\2007, v. 48, N. 1, p.7.pdf |
B 16 Baidakov, V. G. Kinetics of overheated propane and butane fluctuation boiling up [] / V. G. Baidakov, A. M. Kaverin, V. P. Skripov // Zhurnal Fizicheskoi Khimii. - 1986. - V.60, Is.2. - С. 444-448 Рубрики: ФИЗИКА Кл.слова (ненормированные): KINETICS OF OVERHEATED -- PROPANE -- BUTANE -- FLUCTUATION BOILING UP |
S 66 Skokov, V. N. Fliker Noise during Transition to Critical Boiling on a Nonlinear Heater [] / V. N. Skokov, V. P. Koverda // High Temperature. - 2000. - V. 38, N 2. - С. 249-253 Рубрики: ФИЗИКА Кл.слова (ненормированные): FLICKER NOISE -- BOILING CRITICAL -- HEATER NONLINEAR -- NITROGEN -- N -- PULSATION HEAT -- DENSITY SPECTRAL -- SUPERCONDUCTOR HIGHTEMPERATURE -- FLUCTUATION -- TRANSITION PHASE \\\\Expert2\\NBO\\High Temperature\\2000, v.38, p.249.pdf |
G 15 Galashev, A. E. Crystallization of Overcooled Argon in Microheterophase 108-Particle Model-Structure Identification and Heat Fluctuation Resistance of the Systems [] / A. E. Galashev, V. P. Skripov // Kristallografiya. - 1989. - V.34, Is.5. - С. 1254-1258 Рубрики: ФИЗИКА Кл.слова (ненормированные): ARGON |
D 82 Drop on a Hot Plate: The Appearance of 1/f Noise at the Transition to the Ball-Shaped State [] / V. P. Skripov, V. N. Vinogradov, A. V. Skokov, V. P. Reshetnikov, V. P. Koverda // Technical Physics. - 2003. - V. 48, N 6. - С. 682-684 . - ISSN 1063-7842 Рубрики: ФИЗИКА Кл.слова (ненормированные): PHYSICS -- DROPS -- 1/f-NOISE -- BALL-SHAPED STATE -- EVAPORATION OF PENTANE -- PENTANE -- EVAPORATION OF HEXANE -- HEXANE -- EVAPORATION OF WATER -- WATER -- H2O Аннотация: The evaporation of pentane, hexane, and water drops from a horizontal heating surface is studied experimentally. The temperature at which the drops take a completely spherical shape correlates with limit superheat temperatures under quasi-static conditions, suggesting dynamic burnout. Fluctuations in transient regimes are measured by optical and resistive methods. It is found that the spectral densities of the fluctuation intensity are of a flicker nature. Such behavior is associated with percolation in a set of nonequilibrium phase transitions \\\\Expert2\\NBO\\Technical Physics\\2003, v.48, N 10, p.682.pdf |
K 79 Koverda, V. P. 1/f - Noise at non-equilibrium phase transitions / V. P. Koverda, V. N. Skokov, A. V. Reshetnikov // Nucleation Theory and Applications. - Dubna : JINR, 2002. - С. 259-272. - Bibliogr. : p.271-272 (17 ref.) Рубрики: ФИЗИКА Кл.слова (ненормированные): FLICKER NOISE -- FLUCTUATION -- FILMS |
K 79 Koverda, V. P. Statistics of fluctuations with a 1/f spectrum at phase transitions in a spatially distributed system / V. P. Koverda, V. N. Skokov // Physica A. - 2011. - Vol. 390, № 13. - С. 2468-2479 Рубрики: ФИЗИКА Кл.слова (ненормированные): 1/f-NOISE -- FIRST PASSAGE TIME -- AVALANCHES Аннотация: A study has been made on the statistics of fluctuations in a spatially distributed system, which describes the interaction of nonequilibrium phase transitions. It is shown that at a certain intensity of external white noise acting on phase transitions, the time and spatial spectra of fluctuations have power laws S(f)∼f−α and S(k)∼k−γ. The dependence of the exponents α and γ on the value of the diffusion coefficient determining the spatial interaction of fluctuations have been found. Extreme low-frequency fluctuations has been revealed and distribution functions of their duration P(τ)∼τ−β and size P(s)∼s−ν have been determined. It has been found that the exponent α of the frequency dependence of time spectra and the exponent β of the distribution function of the fluctuation duration are related by the relation α+β=2. The exponent of the spatial spectrum γ and the exponent of the size distribution function ν are related by a similar relation: γ+ν=2. The results of experimental studies on fluctuations in a typical nonequilibrium phase transition such as transient modes of water boiling on a wire heater are presented. It was demonstrated that the critical exponents, which describe the power dependence of power spectra of fluctuations and the amplitude distribution of extreme surges, are related by the relation α+β=2 both in experiments and in the theoretical model of interacting heterogeneous phase transitions |
P 28 Parshakova, M. A. Nucleation as a local subsystem fluctuation / M. A. Parshakova, G. V. Ermakov // Physica A. - 2002. - Vol.303, №1-2. - С. 35-47 Рубрики: ФИЗИКА Кл.слова (ненормированные): RANDOM SYSTEMS -- NUCLEATION -- FLUCTUATION Аннотация: A nucleation theory has been advanced, in which a metastable system is considered as the sum of statistically independent subsystems. This theory provides a flexible scheme taking into account actually all initiating factors, including even a separate “weak” point in a system. In the case of a homogeneous nucleation, the difference between the classical and alternative approaches consists in the expression for the preexponential. Depending on the diameter of the critical nucleus, numerical estimates of this preexponential by the two theories differ by 0–4 orders of magnitude for a supersaturated steam and 1–5 orders of magnitude for a superheated liquid |
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 |
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 |
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 |
E 70 Ermakov, G. V. Description of heterogeneous boiling up of superheated liquid / G. V. Ermakov, A. L Gurashkin // Journal of Engineering Thermophysics. - 2007. - Vol.16, №4. - С. 231-235 Рубрики: ФИЗИКА Кл.слова (ненормированные): BOILING -- SUPERHEATED N-HEXANE -- HETEROGENEOUS BOILING Аннотация: The results of measurements of the average expectation time of boiling up of strongly superheated n-hexane in structures from different finely dispersed powders whose smallest size is about 10 nm by using isotherms and isobars are presented. As was proposed by Academician V.P. Skripov, isotherm sections with the heterogeneous boiling up mechanism were processed with the help of Zhurkov’s formula, which is based on the thermofluctuation hypothesis of solid body strength. Thus, temperature dependences of the characteristic volume, whose excess leads to the system division into macroscopic phases, have been found for the systems studied. An approach dealing with the boiling up of superheated liquid as a fluctuation in a locally isolated microvolume is used to describe the isobars. To calculate the work of formation of the characteristic volume, its values obtained at the processing of isotherms are used. The system of equations for the temperature dependence of the average expectation time of n-hexane boiling up in isobars has three empirical constants. A rather accurate description of isobars is obtained at a proper choice of these constants. The result obtained confirms that the idea of Academician V.P. Skripov is successful |
V 70 Vinogradov, A. V. Spectral Characteristics of Fluctuations in Ultrasonic Cavitation of Water and Glycerin / A. V. Vinogradov // Heat Transfer Research. - 2008. - Vol.39, №6. - С. 519-527 Рубрики: ФИЗИКА Кл.слова (ненормированные): FLUCTUATION -- ACOUSTIC CAVITATION -- GLYCERIN Аннотация: The results of experimental investigation of the dynamics of fluctuations in acoustic cavitation of water and glycerin are presented. Near the radiator surface the structures in interacting vapor-gas bubbles having the form of fractal clusters were formed. Using the method of photometric scanning of transmitted laser radiation, the dynamics of fluctuations was investigated. In the transient regime the range of the power of fluctuations changed inversely proportional to frequency. The distributions of local fluctuations differ from Gaussian ones and reveal the properties of scale invariance. The qualitative behavior of the frequency dependence of the spectral density of fluctuations on change in the power of an ultrasonic radiator was investigated. It is shown that the raise of the high-frequency boundary of the flicker behavior point to the buildup of instability and may serve as a precursor of possible large-scale overshoots |
H 62 Heterogeneous boiling-up of superheated liquid at achievable superheat threshold / G. V. Ermakov, E. V. Lipnyagov, S. A. Perminov, A. L Gurashkin // Journal of Chemical Physics. - 2009. - Vol.131, №3. - С. 031102 Рубрики: ФИЗИКА Кл.слова (ненормированные): HOMOGENEOUS NUCLEATION -- BOILING-UP -- LIQUID Аннотация: The classical theory of homogeneous nucleation describes well the superheat threshold observed in experiments. It may be assumed therefore that homogeneous boiling-up of a liquid takes place in experiments, and the theory has been verified experimentally well. The streak photography used in this study showed that boiling-up of a superheated liquid at the threshold of the achievable superheat occurs at a limited number of surface fluctuation centers in a vessel, rather than in the bulk as one would expect with homogeneous nucleation. Thus, the homogeneous theory, which rather accurately describes the heterogeneous threshold of the achievable superheat, obviously is not confirmed in |
D 98 Dynamics of transition processes and structure formation in critical heat-mass transfer regimes during liquid boiling and cavitation / A. N. Pavlenko, V. P. Koverda, A. V. Skokov, A. V. Reshetnikov, A. V. Vinogradov, A. S. Surtaev // Journal of Engineering Thermophysics. - 2009. - Vol.18, №1. - С. 20-38 Рубрики: ФИЗИКА Кл.слова (ненормированные): CRITICAL PHENOMENA -- FALLING FILMS -- LIQUID CAVITATION Аннотация: The results of experimental studies concerning the development of critical phenomena and structure formation in the process of boiling in falling films and during liquid cavitation are given. In conditions of stepwise and periodic pulsed surges of a thermal load, the parameters of formed metastable regular structures and critical parameters of heat-releasing surface drying are shown to be determined by the dynamics of moving wetting boundaries in the process of system self-organization. In the case of high-intensity heat fluxes, decomposition of a falling film is determined by propagation regimes of self-maintaining boiling fronts with a complex shape of intermediate structures. The study of ultrasonic cavitation of water, glycerin, and vacuum oil shows that structures of interacting gas-vapor bubbles (having the form of fractal clusters) are formed near the emitter surface. Spatial structures are characterized by a low-frequency divergence of the power spectra and a scale-invariant function of the fluctuation distributions. The experimental results are in good qualitative agreement with the numerical simulations performed within the theory of 1/f fluctuations in the case of nonequilibrium phase transitions in a spatially distributed system \\\\expert2\\NBO\\Journal of Engineering Thermophysics\\2009, V.18, N 1. P. 20-38.pdf |
R 45 Reshetnikov, A. V. Relaxation and power spectra of low-frequency fluctuations in foams [Электронный ресурс] / A. V. Reshetnikov, V. N. Skokov, V. P. Koverda // Journal of Applied Mechanics and Technical Physics. - 2012. - Vol.53, №6. - P834-838 Рубрики: ФИЗИКА Кл.слова (ненормированные): FOAM FORMATION -- LOW-FREQUENCY FLUCTUATIONS -- POWER SPECTRUM Аннотация: The dynamics of foam formation in a water-glycerin solution was studied to establish the relationship between the relaxation characteristics and the fluctuation power spectrum for a stochastic process. Foaming occurred during the dissociation of the gas-saturated solution and during bubbling of the solution through a porous filter. Two types of relaxation of the foam-exponential and power-law-were revealed. The power-law type of relaxation was observed upon exposure to ultrasound. Relationships between the type of relaxation and the distribution of lowfrequency fluctuations and power spectra was established |
K 79 Koverda, V. P. Entropy maximum in a nonlinear system with the 1/f fluctuation spectrum [Электронный ресурс] / V. P. Koverda, V. N. Skokov // Technical Physics. - 2011. - Vol.56, №11. - P1539-1545 Рубрики: ФИЗИКА Кл.слова (ненормированные): FLUCTUATIONS -- 1/f SPECTRUM -- GIBBS-SHANNON INFORMATIONAL ENTROPY Аннотация: Analysis of the control and subordination is carried out for the system of nonlinear stochastic equations describing fluctuations with the 1/f spectrum and with the interaction of nonequilibrium phase transitions. It is shown that the control equation of the system has a distribution function that decreases upon an increase in the argument in the same way as the Gaussian distribution function. Therefore, this function can be used for determining the Gibbs-Shannon informational entropy. The local maximum of this entropy is determined, which corresponds to tuning of the stochastic equations to criticality and indicates the stability of fluctuations with the 1/f spectrum. The values of parameter q appearing in the definition of these entropies are determined from the condition that the coordinates of the Gibbs-Shannon entropy maximum coincide with the coordinates of the Tsallis entropy maximum and the Renyi entropy maximum for distribution functions with a power dependence |
L 95 Low-frequency fluctuations with 1/f α power spectrum in transient modes of water boiling on a wire heater [Electronic resource] / V. N. Skokov, V. P. Koverda, A. V. Vinogradov, A. V. Reshetnikov // High Temperature. - 2010. - Vol.48, №5. - P706-712 Рубрики: ФИЗИКА Кл.слова (ненормированные): CRITICAL EXPONENT -- DYNAMIC SCALING -- POWER LAW Аннотация: The investigation of transient modes of water boiling on a wire heater reveals the presence of random vibrations with the frequency dependence of power spectra of S ∼ f -α, where the exponent α has values in the range 0.8 ≤ α < 2. Large-scale low-frequency fluctuations exhibiting the property of scale invariance, the duration of which is distributed by the power law P ∼ τ-β, are present in experimental realizations of random processes describing thermal fluctuations. The properties of such fluctuation processes are described using two nonlinear stochastic differential equations which describe the interaction between different phase transitions. Relations of dynamic scaling are determined between the critical exponents which define the frequency dependence of the power spectra of fluctuations α and of the distribution function of the amplitudes of extreme low-frequency fluctuations β. It is demonstrated that the critical exponents are related by the relation α + β = 2 both in the experiments and in the theoretical model of interacting phase transitions. The power spectra of fluctuations are determined in the experiments with greater simplicity and accuracy than the distribution function of extreme amplitudes. In the cases where only the spectral dependence of power spectra of fluctuations is known, the correlations between the exponents enable one to obtain information about the distribution of large-scale surges and estimate dangerous amplitudes |
K 79 Koverda, V. P. Statistics of fluctuations for nonequilibrium phase transitions in spatially distributed system with a 1/f spectrum [Электронный ресурс] / V. P. Koverda, V. N. Skokov // Doklady Physics. - 2009. - Vol.54, №10. - P454-458 Рубрики: ФИЗИКА Кл.слова (ненормированные): 1/F SPECTRUM -- FLUCTUATIONS -- NON-EQUILIBRIUM PHASE Аннотация: The statistics of fluctuations for non-equilibrium phase transitions in spatially distributed system with a 1/f Spectrum has been reported. The systems in which it is possible to observe the 1/f noise belong to various fields of investigations the physics of solids and electronics, astrophysics, geophysics, biology, economy, and social sciences. The stationary stochastic processes with the 1/f spectrum are characterized by flashes and avalanche dynamics. The fluctuation power spectra more often are not measured directly in the self organized criticality models but calculated from the found avalanche distributions. The fluctuation spectra for the spatially distributed system and for other values of diffusivity have the power dependence. The initial conditions for each spatial point of these two systems were chosen with opposite signs corresponding to the different potential valleys. |