Б 90 Буланов, Н. В. Поверхностное натяжение жидкости в условиях быстрого обновления поверхности при испарении [] = Surface Tension of a Liquid under the Conditions of a Fast Surface Renewal during Evaporation / Н. В. Буланов, В. П. Скрипов // Коллоидный журнал. - 2003. - Т. 65, N 5. - 1-8: табл. - Библиогр.: с. 588 (22 назв.) . - ISSN 0023-2912 Рубрики: ФИЗИКА Кл.слова (ненормированные): НАТЯЖЕНИЕ ПОВЕРХНОСТНОЕ -- ПОВЕРХНОСТНОЕ НАТЯЖЕНИЕ -- ЖИДКОСТИ -- ПОВЕРХНОСТИ -- ИСПАРЕНИЕ -- КАПИЛЛЯРНЫЙ СПОСОБ ИЗМЕРЕНИЯ -- ТЕПЛООБМЕН -- МЕНИСК Аннотация: Рассмотрен новый капиллярный способ измерения поверхностного натяжения в условиях быстрого обновления поверхности при ее испарении. Для максимально достигнутых скоростей испарения н-пентана 0.6 кг м(-2)с(-1) и воды 0.14 кг м(-2)с(-1) отклонения поверхностного натяжения от равновесных значений можно объяснить изменением формы мениска в условиях интенсивного теплообмена |
G 15 Galashev, A. E. Computer investigation of the structure of Si73 clusters surrounded by hydrogen [Текст] / A. E. Galashev, I. A. Izmodenov // Glass Physics and Chemistry. - 2008. - Vol. 34, № 2. - С. 173-181 Рубрики: ФИЗИКА Кл.слова (ненормированные): HYDROGEN Аннотация: The stabilization of the structure of Si73 clusters that are surrounded by 60 hydrogen atoms and subjected to seventeenfold stepwise heating from 35 to 1560 K (in steps of ?90 K) is investigated using the molecular dynamics method. The analysis is performed for clusters of three types, i.e., a particle assembled from an icosahedron and a fullerene, a nanocrystal, and a particle with a random atomic packing. In all cases, an increase in the temperature in the course of heating is accompanied by evaporation of a Si atom from the clusters and an increase in the size of silicon particles. The temperature of detachment of Si atoms from clusters is lowest for the cluster with a random atomic packing and highest for the nanocrystal. The nanoassembled particle has the most stable number (close to four) of Si-Si bonds per atom over the entire temperature range 35 ? T ? 1560 K. For each type of Si73 clusters, the mean length of the Si-Si bond decreases with an increase in the temperature. According to the radial distribution functions, the Si73 clusters have different structures even at the temperature T = 1560 K. The distributions of bond angles reflect the presence of fourfold symmetry elements in the nanoassembled cluster and the nanocrystal. The relative depth of “penetration” of hydrogen atoms into the cluster is largest for the nanocrystal and smallest for the nanoassembled nanoparticle. The largest number of hydrogen atoms is “adsorbed” on the particle with a random atomic packing. \\\\Expert2\\NBO\\Glass Physics and Chemistry\\2008, v. 34, N 2, p.173.pdf |
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 |
B 93 Bulanov, N. V. Surface Tension of a Liquid under the Conditions of a Fast Surface Renewal during Evaporation [] / N. V. Bulanov, V. P. Skripov // Colloid Journal (Translation of Kolloidnyi Zhurnal). - 2003. - V. 65, N 5. - С. 531-538. - Bibliogr.: p. 588 (22 ref.) . - ISSN 0023-2912 Рубрики: ФИЗИКА Кл.слова (ненормированные): SURFACE TENSION -- LIQUIDS -- SURFACES -- FAST SURFACE RENEWAL -- EVAPORATION -- MENISCUS -- HEAT EXCHANGE \\\\Expert2\\NBO\\Colloid Journal\\2003, V.65, N5,531.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 |
I-70 Investigation of startup behaviors of a loop-heat pipe / H. X. Zhang, G. P. Lin, T. Ding, Yu. F. Maydanik, R. G. Sudakov // Journal of Termophysics and Heat Transfer. - 2005. - Vol. 19, № 4. - С. 509-518 Рубрики: ФИЗИКА Кл.слова (ненормированные): HEAT PIPES -- VAPOR/LIQUID DISTRIBUTION -- VAPOR GROOVES Аннотация: The results of ground experiments on startup behaviors of a loop heat pipe are presented. One objective is to investigate the effects of working conditions on the startup of loop heat pipes. Startup behaviors as functions of various parameters, including the vapor/liquid distribution-in the evaporator, startup heat load, sink temperature, and adverse elevation are described and explained. The physical process of startup is described, and the explanation that pressure transfer leads to the saturated temperature rise in the compensation chamber during startup is discussed. The other objective is to investigate the effect of startup on the steady-state operation of loop heat pipes. Test results indicate that evaporation inside the wick tends to occur at low startup heat loads when the evaporator, including the vapor grooves and the evaporator core, is flooded with liquid. Some peculiar phenomena, including evaporation inside the wick, temperature oscillation at the condenser inlet, and reverse flow equilibrium, which lead to higher operating temperatures, were observed during startups |
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 |
L 88 Loop Heat Pipes for Cooling Systems of Servers / Yu. F. Maydanik, S. V. Vershinin, V. G. Pastukhov, S. Fried // IEEE Transactions on Components and Packaging Technologies. - 2010. - Vol.33, №2. - С. 416-423 Рубрики: ФИЗИКА Кл.слова (ненормированные): HEAT-TRANSFER DEVICE -- LHPs -- OPTERON CPUs Аннотация: Loop heat pipes (LHPs) are exceptionally efficient heat-transfer devices that employ a closed loop evaporation-condensation cycle that can be used to cool densely packed electronic systems that reject large quantities of heat, including computers and their central processing units (CPUs). Tests were carried out on miniature ammonia LHPs with a CPU thermal simulator using different ways of condenser cooling. The possibility of maintaining the cooled object temperatures between 40°C and 70°C with heat load changing from 100 to 320 W was demonstrated. Subsequent tests of these devices in a 1U computer with dual core advanced micro devices Opteron CPUs, dissipating between 95 and 120 W, have confirmed the advantages and heat transfer efficiency of LHP-based cooling systems used to cool CPU in 1U chassis |
R 55 Rifert, V. G. Evaporation heat transfer in liquid films flowing down horizontal smooth and longitudinaly profiled tubes / V. G. Rifert, Ju. V. Putilin, V. L. Podbereznyi // Journal of Enhanced Heat Transfer . - 2001. - Vol.8, №2. - С. 91-97 Рубрики: ФИЗИКА Кл.слова (ненормированные): ENHANCEMENT -- EVAPORATION -- LONGITUDINAL PROFILE Аннотация: The heat transfer mechanism of a liquid film flowing down horizontal tubes is studied by experimental determination of local and average heat transfer coefficients. A method of its enhancement is developed which is based on the break-down of the heat boundary layer by longitudinal fins and grooves. The calculated functions and recommendations on geometrical parameters of profiling, which allow heat transfer enhancement by a factor of 1.4-1.9 and overall "vapor-liquid" heat transfer by a factor of 1.3-1.5, are given |
M 19 Maydanik, Yu. F. Development and Tests of Miniature Loop Heat Pipe with a Flat Evaporator / Yu. F. Maydanik, S. V. Vershinin, M. A. Chenysheva // SAE 2000 Transaction - Journal of Aerospace. - 2001. - Paper Number: 2000-01-2491 Рубрики: ФИЗИКА Кл.слова (ненормированные): AMMONIA MINIATURE -- LOOP HEAT PIPE -- FLAT EVAPORATOR Аннотация: The paper presents the results of analysis, development and tests of an ammonia miniature loop heat pipe (MLHP) with a flat evaporator, which has an active-zone diameter of 30mm. The length and the diameter of the vapor and the liquid lines are 1m and 2/1.2mm. The device serviceability has been demonstrated at a horizontal and a vertical orientation in 1-g conditions. The maximum heat load achieved on trials was equal, respectively, to 160W and 120W, which corresponds to a heat flow in the evaporation zone of 23 W/cm 2 and 17 W/cm 2 . The minimum thermal resistance at nominal heat loads from 40 to 80 W varied in the range from 0.42 W/m 2 K to 0.59 W/m 2 K. A comparison has been made with a model MLHP with a cylindrical evaporator equipped with a copper and aluminum “sa |
V 50 Vershinin, S. V. Hysteresis phenomena in loop heat pipes / S. V. Vershinin, Yu. F. Maydanik // Applied Thermal Engineering. - 2007. - Vol.27, №5-6. - С. 962-968 Рубрики: ФИЗИКА Кл.слова (ненормированные): LOOP HEAT PIPE -- CAPILLARY METHOD -- EVAPORATION Аннотация: Testing of loop heat pipes (LHPs) has shown that the heat-load dependence of the operating temperature is not always unambiguous. It may have a hysteresis nature. It has been found that temperature hysteresis is connected with changes in the liquid distribution between the compensation chamber (CC) and the condenser. Analysis makes it possible to distinguish three types of temperature hysteresis. In the first case this redistribution is caused by the change in the amount of the parasitic heat flow that penetrates into the CC, which in its turn is a result of heat-transfer hysteresis in the evaporation zone. In the second, temperature hysteresis is connected with the liquid metastable state, which leads to a delay of formation of the vapor phase in the compensation chamber. The reason for hysteresis of the third type is the change of the initial liquid distribution in an LHP during a start-up |
Heat and Mass Transfer in Evaporator of Loop Heat Pipe // Journal of Termophysics and Heat Transfer. - 2009. - Vol.23, №4. - С. 725-731 Кл.слова (ненормированные): HEAT-EXCHANGE -- EVAPORATOR -- LOOP HEAT PIPE Аннотация: Investigation of heat-exchange processes in the evaporator of a loop heat pipe is important for the development of heat transfer devices with low thermal resistances. A two-dimensional mathematical model of the evaporator active zone is presented. Three modes of vapor generation in the wick have been examined, where each differs in the mechanism of the vapor phase formation and in the saturation of the capillary structure: 1) evaporation to the vapor grooves, 2) volumetric evaporation in the two-phase zone, and 3) volumetric evaporation in the two-phase zone separated from the heated wall of the evaporator by dried zones. Conditions identifying changes between modes have been formulated. Structural characteristics of the wick with different pore sizes have been taken into account. Using a numericalanalytical method, results were obtained for three copper loop heat pipes with biporous wicks, where the working fluid was water for one of the loop heat pipes and methanol for the other two. The heat-load dependent temperature drop between the evaporator wall and the vapor in the vapor grooves has been presented. Additionally, a comparative analysis of calculated and experimental results was performed |
C 51 Chenysheva, M. A. Simulation of thermal processes in a flat evaporator of a copper-water loop heat pipe under uniform and concentrated heating [Электронный ресурс] / M. A. Chenysheva, Yu. F. Maydanik // International Journal of Heat and Mass Transfer. - 2012. - Vol.55, № 25-26. - P7385-7397 Рубрики: ФИЗИКА Кл.слова (ненормированные): 3D MODEL -- EVAPORATION -- FLAT EVAPORATOR Аннотация: A 3D model has been developed for investigating heat and mass transfer in a flat evaporator of a copper-water loop heat pipe. It takes into account heat-transfer processes in the active zone, the barrier layer of the wick, the wall and the compensation chamber. The problem was solved by the finite difference method with the use of a nonuniform grid adapted to the configuration of the flat evaporator and its geometric peculiarities. Investigations have been carried out for understanding the effect of the heating zone size on heat distribution in the evaporator. The heating area was 9 cm 2 with a uniform heat supply and 1 cm 2 with a concentrated one. Numerical simulation has been performed for a heat load range from 20 to 1100 W. Data have shown that a decrease in the heating area at a fixed heat load results in both increasing temperature on the evaporator wall under the heater and local wick draining in the active zone. The results of the model have been verified using results of experimental tests. |
C 51 Chernysheva, M. A. 3D-model for heat and mass transfer simulation in flat evaporator of copper-water loop heat pipe [Electronic resource] / M. A. Chernysheva, Yu. F. Maydanik // Applied Thermal Engineering. - 2012. - Vol.33-34, №1. - P124-134 Рубрики: ФИЗИКА Кл.слова (ненормированные): EVAPORATION -- FLAT EVAPORATOR -- MATHEMATICAL MODEL Аннотация: This paper presents a three-dimension mathematical model of a flat evaporator of a loop heat pipe which takes into account the peculiarities of the evaporator configuration and the specific character of a one-side heat load supply. All the main structural elements of the evaporator, such as its body, wick, vapor-removal grooves, barrier layer and compensation chamber, are included in the model. The intensity of heat-exchange processes during evaporation in the active zone is determined by local drops between the temperature at the wick surface and the vapor temperature. The effects of drying the wick in the evaporation zone are also taken into account. The problem was solved by a numerical method. The results of calculations are presented for a copper evaporator and water as a working fluid in the heat load range from 20 to 1100 W. A comparative analysis of calculated and experimental data has been made \\\\expert2\\NBO\\Applied Thermal Engineering\\2012, v. 33-34, p.124.pdf |
C 51 Chernysheva, M. A. Peculiarities of heat transfer in a flat disk-shaped evaporator of a loop heat pipe [Electronic resource] / M. A. Chernysheva, Yu. F. Maydanik // International Journal of Heat and Mass Transfer. - 2016. - Vol. 92. - С. 1026-1033. - Bibliogr. : p. 1033 (16 ref.) Рубрики: ФИЗИКА Кл.слова (ненормированные): LOOP HEAT PIPES -- POROUS MATERIAL -- EVAPORATOR Аннотация: Two models of a flat disk-shaped evaporator of a loop heat pipe have been developed for analyzing the effect of the convective component on heat transfer in a wick, and also on heat-exchange processes in an evaporation zone. Simulation data were obtained for two evaporators. The first evaporator was made entirely of copper, and the second had a body of stainless steel and a nickel wick. The geometrical dimensions of the evaporators were equal. The diameter of the heating zone was 30 mm. Calculations were made for heat fluxes from 2.8 ⋅ 104 to 4.2 ⋅ 105 W/m2. Water was used as a working fluid. An analysis of the results has shown that the contribution of the convective component to the overall heat transfer is small. The higher the thermal conductivity of the wick, the smaller the effect that the convection has on the temperature distribution in the evaporator. \\\\expert2\\nbo\\International Journal of Heat and Mass Transfer\\2016, v. 92, p.1026-1033.pdf |
Б 90 Буланов, Н. В. Поверхностное натяжение жидкости в условиях быстрого обновления поверхности при испарении [] = Surface Tension of a Liquid under the Conditions of a Fast Surface Renewal during Evaporation / Н. В. Буланов, В. П. Скрипов // Коллоидный журнал. - 2003. - Т. 65, N 5. - 1-8: табл. - Библиогр.: с. 588 (22 назв.) . - ISSN 0023-2912 Рубрики: ФИЗИКА Кл.слова (ненормированные): НАТЯЖЕНИЕ ПОВЕРХНОСТНОЕ -- ПОВЕРХНОСТНОЕ НАТЯЖЕНИЕ -- ЖИДКОСТИ -- ПОВЕРХНОСТИ -- ИСПАРЕНИЕ -- КАПИЛЛЯРНЫЙ СПОСОБ ИЗМЕРЕНИЯ -- ТЕПЛООБМЕН -- МЕНИСК Аннотация: Рассмотрен новый капиллярный способ измерения поверхностного натяжения в условиях быстрого обновления поверхности при ее испарении. Для максимально достигнутых скоростей испарения н-пентана 0.6 кг м(-2)с(-1) и воды 0.14 кг м(-2)с(-1) отклонения поверхностного натяжения от равновесных значений можно объяснить изменением формы мениска в условиях интенсивного теплообмена |
G 15 Galashev, A. E. Computer investigation of the structure of Si73 clusters surrounded by hydrogen [Текст] / A. E. Galashev, I. A. Izmodenov // Glass Physics and Chemistry. - 2008. - Vol. 34, № 2. - С. 173-181 Рубрики: ФИЗИКА Кл.слова (ненормированные): HYDROGEN Аннотация: The stabilization of the structure of Si73 clusters that are surrounded by 60 hydrogen atoms and subjected to seventeenfold stepwise heating from 35 to 1560 K (in steps of ?90 K) is investigated using the molecular dynamics method. The analysis is performed for clusters of three types, i.e., a particle assembled from an icosahedron and a fullerene, a nanocrystal, and a particle with a random atomic packing. In all cases, an increase in the temperature in the course of heating is accompanied by evaporation of a Si atom from the clusters and an increase in the size of silicon particles. The temperature of detachment of Si atoms from clusters is lowest for the cluster with a random atomic packing and highest for the nanocrystal. The nanoassembled particle has the most stable number (close to four) of Si-Si bonds per atom over the entire temperature range 35 ? T ? 1560 K. For each type of Si73 clusters, the mean length of the Si-Si bond decreases with an increase in the temperature. According to the radial distribution functions, the Si73 clusters have different structures even at the temperature T = 1560 K. The distributions of bond angles reflect the presence of fourfold symmetry elements in the nanoassembled cluster and the nanocrystal. The relative depth of “penetration” of hydrogen atoms into the cluster is largest for the nanocrystal and smallest for the nanoassembled nanoparticle. The largest number of hydrogen atoms is “adsorbed” on the particle with a random atomic packing. \\\\Expert2\\NBO\\Glass Physics and Chemistry\\2008, v. 34, N 2, p.173.pdf |
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 |
B 93 Bulanov, N. V. Surface Tension of a Liquid under the Conditions of a Fast Surface Renewal during Evaporation [] / N. V. Bulanov, V. P. Skripov // Colloid Journal (Translation of Kolloidnyi Zhurnal). - 2003. - V. 65, N 5. - С. 531-538. - Bibliogr.: p. 588 (22 ref.) . - ISSN 0023-2912 Рубрики: ФИЗИКА Кл.слова (ненормированные): SURFACE TENSION -- LIQUIDS -- SURFACES -- FAST SURFACE RENEWAL -- EVAPORATION -- MENISCUS -- HEAT EXCHANGE \\\\Expert2\\NBO\\Colloid Journal\\2003, V.65, N5,531.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 |