Journal of Engineering Thermophysics最新文献

Pressure Drop Calculation at Flow Boiling in a Minichannel for a Wide Range of Reduced Pressures 大范围减压条件下小通道流动沸腾压降计算

IF 1.3 4区工程技术

Journal of Engineering Thermophysics Pub Date : 2025-01-17 DOI: 10.1134/S1810232824040040

A. V. Belyaev, N. E. Sidelnikov, E. I. Gareev, A. V. Dedov

{"title":"Pressure Drop Calculation at Flow Boiling in a Minichannel for a Wide Range of Reduced Pressures","authors":"A. V. Belyaev, N. E. Sidelnikov, E. I. Gareev, A. V. Dedov","doi":"10.1134/S1810232824040040","DOIUrl":"10.1134/S1810232824040040","url":null,"abstract":"This paper studies the validity of prediction tools for two-phase flow pressure drops in wide range of reduced pressures based on the comparison between new experimental results and theoretical results predicted with the commonly used methods. The original dataset was obtained in a vertical uniformly heated minichannel 1.1 mm inner diameter with R125 and RC318 as working fluids. Uniform heating was carried out by electric current, simulating real flow conditions in heat exchangers, which is a distinctive feature of this work from most similar studies. The mass velocity varied in the range from 200 to 1400 kg/(m2s), the reduced pressure varied from 0.132 to 0.70, the heat flux density range was from 4 to 322 kW/m2, the inlet vapor quality was set from −0.2 to −0.06 and outlet vapor quality reached 1 at minimum flow rates. The database is composed of 115 data points of two-phase flow boiling and was compared against well-known two-phase pressure drop prediction methods. The effect of the reduced pressure on the ability of the methods to predict the pressure drop was pointed out.","PeriodicalId":627,"journal":{"name":"Journal of Engineering Thermophysics","volume":"33 4","pages":"706 - 721"},"PeriodicalIF":1.3,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142995400","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Heat Transfer during Condensation of Liquid Vapor on Horizontal Circular Tube in Hydrophobic Granular Layer 疏水颗粒层中水蒸汽在水平圆管内冷凝过程中的传热

IF 1.3 4区工程技术

Journal of Engineering Thermophysics Pub Date : 2025-01-17 DOI: 10.1134/S1810232824040143

M. I. Shilyaev, E. M. Khromova, A. R. Bogomolov

{"title":"Heat Transfer during Condensation of Liquid Vapor on Horizontal Circular Tube in Hydrophobic Granular Layer","authors":"M. I. Shilyaev, E. M. Khromova, A. R. Bogomolov","doi":"10.1134/S1810232824040143","DOIUrl":"10.1134/S1810232824040143","url":null,"abstract":"Analytical modeling of heat transfer during condensation onto a horizontal round tube placed in a hydrophobic granular layer has been performed. According to generalized experimental results of the authors, the area under study was divided into three regimes of the condensate film flow: Re (< 5), (5 < {rm Re} < 10), and Re (> 10). For the first two regimes, in the absence of effect of capillary forces, theoretical solutions were found based on the representation of a near-wall pore channel in the form of a flat annular slot with hydrophobic side surfaces; the solutions are in good agreement with the experimental data. At Re (> 10), a self-similar regime of the hydrodynamics of the condensate film settles, independent of the Re number, with a constant mean film thickness over the tube perimeter and the condensate part not involved in the heat transfer in the tube draining into the pore space of the layer. In all analyzed cases, there is heat transfer deterioration by two to three times on a horizontal tube in a hydrophobic layer in comparison with a smooth hydrophilic tube, because of the peculiarities of the hydrodynamics of the condensate flow in the wall pore channels. For all modes, formulas were obtained for calculation of the Nusselt numbers of heat transfer in dependence on the Re number.","PeriodicalId":627,"journal":{"name":"Journal of Engineering Thermophysics","volume":"33 4","pages":"840 - 851"},"PeriodicalIF":1.3,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142995446","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Experimental Research on Combined Methods against Icing of Wind Turbine Blades 风力发电机叶片防结冰联合方法试验研究

IF 1.3 4区工程技术

Journal of Engineering Thermophysics Pub Date : 2025-01-17 DOI: 10.1134/S181023282404009X

V. G. Meledin, I. K. Kabardin, S. V. Dvoynishnikov, V. O. Zuev, O. G. Mukhin, S. V. Kakaulin, M. R. Gordienko, K. S. Zubanov, K. I. Stepanov, N. S. Goltsev, E. M. Tolstopyatov, P. N. Grakovich, L. F. Ivanov, D. V. Brel, L. A. Kalinin

{"title":"Experimental Research on Combined Methods against Icing of Wind Turbine Blades","authors":"V. G. Meledin, I. K. Kabardin, S. V. Dvoynishnikov, V. O. Zuev, O. G. Mukhin, S. V. Kakaulin, M. R. Gordienko, K. S. Zubanov, K. I. Stepanov, N. S. Goltsev, E. M. Tolstopyatov, P. N. Grakovich, L. F. Ivanov, D. V. Brel, L. A. Kalinin","doi":"10.1134/S181023282404009X","DOIUrl":"10.1134/S181023282404009X","url":null,"abstract":"The dynamic development and enhancement of the efficiency and safety of power engineering in the Arctic and remote Siberian regions of Russia are promising and relevant. The aim of this work is search for scientifically based approaches and methods against icing, which is one of the main problems hindering efficient use of wind turbines for autonomous power supply to remote settlements in the Far North. The necessity in the research and its relevance are confirmed by the growing interest in the development of the Arctic region by the leading world countries. The presented research strives for an optimal strategy against icing of wind turbine blades in climatic conditions typical of the Arctic coast of Russia. The efficiency of combined anti-icing methods relying on the use of aerodynamically transparent substrates, hierarchical superhydrophobic (HSH) coatings, and materials based on polytetrafluoroethylene fiber for wind turbine blades in Arctic climatic conditions was experimentally studied. It is a fundamentally new approach, which has no world analogues. For verification of the efficiency of the de-icing systems and identification of the most efficient protection methods or combination of them, an experimental comparison was made for the efficiency of superhydrophobic coatings when used separately and together with various traditional de-icing methods based on heaters and ultrasonic and vibration devices. It has been shown that the integral use of the proposed methods and approaches successfully solves the problem of developing a general anti-icing strategy.","PeriodicalId":627,"journal":{"name":"Journal of Engineering Thermophysics","volume":"33 4","pages":"779 - 791"},"PeriodicalIF":1.3,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142995398","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Droplet Impacts on Cold Cylindrical Copper Surfaces 液滴对冷圆柱形铜表面的冲击

IF 1.3 4区工程技术

Journal of Engineering Thermophysics Pub Date : 2025-01-17 DOI: 10.1134/S181023282404012X

J. J. Tian, M. P. Wu, S. Mehendale, Z. Zhang

{"title":"Droplet Impacts on Cold Cylindrical Copper Surfaces","authors":"J. J. Tian, M. P. Wu, S. Mehendale, Z. Zhang","doi":"10.1134/S181023282404012X","DOIUrl":"10.1134/S181023282404012X","url":null,"abstract":"Currently, we investigate the collision process of water droplets on cold cylindrical copper surfaces by means of a video camera and a cooling testbed. The solidification of water vapor on cold metal surfaces increases the friction of contacting liquids is an unavoidable factor, so we experimented with a uniform atmospheric pressure and relative humidity environment. The paramount purpose of this experiment was to avail oneself of the change in viscosity due to temperature change and the change in radius of copper cylinder to understand its effect on droplet impact conducting heat and freezing. The results show that the substrate viscosity (frost layer) has marginal effect on the time for a droplet to reach maximum diffusion in the two main droplet movement directions. In addition, droplet diffusion on cold cylindrical copper surfaces consists of three processes: spreading stage, transitional stage and steady stage. Among these three phases, power function fitting works best in the spreading stage. Besides, we have used the composite spreading coefficient (gamma) to describe the speed of spreading. For any radius cylinder, the cooler the temperature, the bigger the average value of the composite spreading coefficient (gamma) below 0°C than above 0°C. The larger the composite spreading coefficient (gamma) is, the more slowly the droplet dimensionless spreading arc length changes with dimensionless time. Moreover, droplets between 0°C and −5°C sometimes show post-collision supercooling, which is related to surface viscosity instability and the contribution of surface shape to droplet retraction.","PeriodicalId":627,"journal":{"name":"Journal of Engineering Thermophysics","volume":"33 4","pages":"810 - 832"},"PeriodicalIF":1.3,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142995443","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Some Features of the Formation of Polycrystalline Conglomerates of Methane Hydrate at the Interface Foam—Solution of Surfactants 表面活性剂界面泡沫溶液中甲烷水合物多晶聚集体形成的若干特征

IF 1.3 4区工程技术

Journal of Engineering Thermophysics Pub Date : 2025-01-17 DOI: 10.1134/S1810232824040118

T. P. Adamova, A. Y. Manakov, D. S. Elistratov, A. A. Chernov

引用次数: 0

Simulation of Heat Transfer during Injection of Annular Gas-Droplet Jet into Turbulent Cross-Flow 湍流横流中环形气滴射流的传热模拟

IF 1.3 4区工程技术

Journal of Engineering Thermophysics Pub Date : 2025-01-17 DOI: 10.1134/S1810232824040106

M. A. Pakhomov

引用次数: 0

Diagnostics of Boiling Crisis 沸腾危机的诊断

IF 1.3 4区工程技术

Journal of Engineering Thermophysics Pub Date : 2025-01-17 DOI: 10.1134/S1810232824040131

A. V. Reshetnikov, V. G. Pastukhov, V. N. Skokov, A. A. Akashev, A. V. Vinogradov, V. P. Koverda

引用次数: 0

Erratum to: Investigation of the Local Equilibrium Approximation in a Planar Momentumless Turbulent Wake in a Passively Stratified Fluid 对被动分层流体中平面无动量湍流尾迹局部平衡近似研究的勘误

IF 1.3 4区工程技术

Journal of Engineering Thermophysics Pub Date : 2025-01-17 DOI: 10.1134/S1810232824040192

V. N. Grebenev, A. G. Demenkov, G. G. Chernykh

引用次数: 0

Erratum to: Analytical Study of Conjugated Heat Transfer of a Microchannel Fluid Flow between Two Parallel Plates 两个平行板间微通道流体流动的共轭传热分析研究

IF 1.3 4区工程技术

Journal of Engineering Thermophysics Pub Date : 2025-01-17 DOI: 10.1134/S1810232824040180

A. S. Al-shyyab, F. H. Darwish, M. A. Al-Nimr, B. J. Alshaer

引用次数: 0

Features of Measurement of Local Parameters of Near-Wall Liquid Films in Supersonic Nozzles 超声速喷管近壁液膜局部参数测量特点

IF 1.3 4区工程技术

Journal of Engineering Thermophysics Pub Date : 2025-01-17 DOI: 10.1134/S1810232824040027

V. N. Yarygin, I. V. Yarygin, V. G. Prikhodko, A. D. Nazarov

引用次数: 0