Journal of Engineering Thermophysics最新文献_第8页

Energy Recovery Based on Exhaust Gas Recirculation and Heat Regeneration Processes Applied in a Firewood Boiler 基于废气再循环和热再生工艺的柴火锅炉能量回收

IF 2.4 4区工程技术

Journal of Engineering Thermophysics Pub Date : 2023-11-08 DOI: 10.1134/S1810232823030062

N. R. Caetano, B. P. da Silva, A. C. Ruoso, A. G. Avila, L. A. O. Rocha, G. Lorenzini

引用次数: 0

Experimental Investigation of Parabolic Trough Solar Collector Thermal Efficiency Enhanced by Different Reflective Materials 不同反射材料提高抛物面槽太阳能集热器热效率的实验研究

IF 2.4 4区工程技术

Journal of Engineering Thermophysics Pub Date : 2023-11-08 DOI: 10.1134/S1810232823030128

A. Y. Al-Rabeeah, I. Seres, I. Farkas

{"title":"Experimental Investigation of Parabolic Trough Solar Collector Thermal Efficiency Enhanced by Different Reflective Materials","authors":"A. Y. Al-Rabeeah, I. Seres, I. Farkas","doi":"10.1134/S1810232823030128","DOIUrl":"10.1134/S1810232823030128","url":null,"abstract":"This experimental study presents the thermal efficiency enhancement of a parabolic trough solar collector (PTSC) system using different refractive surfaces and various mass flow rates. Two PTSC models were used to compare the aluminium sheet (AS) and silver chrome film (SCF) under the weather conditions of Hungary. Initially, similarity tests of the two collectors were carried out using the aluminium reflective surfaces with a mass flow rate of 90 L/h. According to the test results, the average thermal efficiency between collectors did not exceed 0.3%. Afterwards, the PTSC was compared with an evacuated U-shaped glass tube at different mass flow rates, namely 30, 60, 90, and 120 L/h. According to the experimental results, the maximum heat removal factor of PTSC for both SCF and AS at 120 L/h was 58.59% and 46.02%, respectively. Moreover, the maximum thermal efficiency with AS obtained for 120, 90, 60, and 30 L/h mass flow rates reached 27%, 22.84%, 18.9%, and 14.86%, respectively. Likewise, the maximum thermal efficiency with SCF at these mass flow rates attained 46.84%, 39.73%, 37.47%, and 33.68%, respectively. Conclusively, the PTSC thermal performance using SCF is superior to that of AS regardless of mass flow rate.","PeriodicalId":627,"journal":{"name":"Journal of Engineering Thermophysics","volume":"32 3","pages":"579 - 590"},"PeriodicalIF":2.4,"publicationDate":"2023-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71909649","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

Effect of Rotation on Boundary Conditions at the Interface of Two Immiscible Fluids 旋转对两种非混相流体界面边界条件的影响

IF 2.4 4区工程技术

Journal of Engineering Thermophysics Pub Date : 2023-11-08 DOI: 10.1134/S1810232823030086

I. V. Naumov, B. R. Sharifullin, M. A. Herrada, V. N. Shtern

{"title":"Effect of Rotation on Boundary Conditions at the Interface of Two Immiscible Fluids","authors":"I. V. Naumov, B. R. Sharifullin, M. A. Herrada, V. N. Shtern","doi":"10.1134/S1810232823030086","DOIUrl":"10.1134/S1810232823030086","url":null,"abstract":"Recent experimental studies revealed the development of slip at the interface of a steady axisymmetric swirling flow of two immiscible fluids. As swirl increases, the slip changes the flow topology scenario compared with that numerically predicted using the velocity continuity condition. This phenomenon of fundamental and practical interest has not been well understood yet. What condition should replace the velocity continuity has remained unknown. Our study addresses this problem by providing detailed experimental and numerical investigations of the flow in the interface vicinity. The bulk flow is driven by the rotating lid in a vertical cylindrical container—a model of vortex bioreactor. The centrifugal force pushes the upper fluid from the axis to the sidewall near the lid and the fluid goes back to the axis near the interface. This centrifugal circulation drives the anti-centrifugal circulation of the lower fluid at a slow rotation. As the rotation speeds up, a new flow cell emerges below the interface-axis intersection. It expands radially and downward occupying the lower-fluid domain. During these topological transformations, the flow remains steady and axisymmetric with no visible deformation of the interface. Using the advanced PIV experimental and numerical techniques, we explore the distribution of azimuthal and radial velocities in the interface vicinity and reveal that the azimuthal velocity is continuous while the radial velocity has a jump at the interface. The radial velocity tends to zero in the upper fluid. In contrast, the radial velocity does not tend to zero and satisfies the stress-free condition in the lower fluid at the interface. The numerical simulations under these conditions are in qualitative agreement with the experiment.","PeriodicalId":627,"journal":{"name":"Journal of Engineering Thermophysics","volume":"32 3","pages":"508 - 520"},"PeriodicalIF":2.4,"publicationDate":"2023-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71909568","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

Significance of Thermal Boundary Layer Analysis of MHD Chemically Radiative Dissipative Casson Nanofluid Flow over a Stretching Sheet with Heat Source MHD化学辐射耗散Casson纳米流体在带热源拉伸薄板上流动的热边界层分析意义

IF 2.4 4区工程技术

Journal of Engineering Thermophysics Pub Date : 2023-11-08 DOI: 10.1134/S1810232823030116

S. Karanamu, J. Konda, S. K. Vali

引用次数: 0

Reducing Ice Adhesion by Using Nanostructured Plastic Polymer Coatings for De-Icing of Wind Turbine Blades 纳米结构塑料聚合物涂层在风力涡轮机叶片除冰中的应用

IF 2.4 4区工程技术

Journal of Engineering Thermophysics Pub Date : 2023-11-08 DOI: 10.1134/S181023282303013X

V. G. Meledin, S. V. Dvoynishnikov, K. I. Stepanov, D. G. Mukhin, M. R. Gordienko, S. V. Kakaulin, V. E. Ledovsky, K. S. Zubanov, V. O. Zuev, N. I. Yavorsky, G. V. Bakakin, I. K. Kabardin

引用次数: 0

Heat Transfer during Evaporation/Boiling of Horizontal Layers of Liquid at Low Pressure 低压下水平液体层蒸发/沸腾过程中的传热

IF 2.4 4区工程技术

Journal of Engineering Thermophysics Pub Date : 2023-11-08 DOI: 10.1134/S1810232823030025

A. E. Brester, D. A. Shvetsov, V. I. Zhukov, A. N. Pavlenko

{"title":"Heat Transfer during Evaporation/Boiling of Horizontal Layers of Liquid at Low Pressure","authors":"A. E. Brester, D. A. Shvetsov, V. I. Zhukov, A. N. Pavlenko","doi":"10.1134/S1810232823030025","DOIUrl":"10.1134/S1810232823030025","url":null,"abstract":"In this work, experimental data on the heat transfer in a horizontal layer of liquid are obtained for wide ranges of the layer height and reduced pressure. Explosive boiling-up of liquid at low reduced pressures, when significant fluctuations of the pressure, heating surface temperature, and heat flux were observed, is considered. For this condition, the problem of determination of the temperature head is analyzed, as well as uncertainties of its measurement. The experimental data obtained at different layer heights and pressures were compared with the known calculation formulas derived for determination of the heat transfer coefficient during nucleate boiling for analysis of the range of applicability of these formulas. It is shown that at low reduced pressures, the experimental data are generalized well by Yagov’s formula, and the experimental data obtained at moderate reduced pressures at nucleate boiling are generalized well by Gogonin’s formula. Both formulas were obtained for pool boiling. With the help of Pioro’s formula in which we corrected the coefficients and exponents at the Prandtl number and heat flux, we managed to summarize the experimental data over the entire range of the reduced pressure and the liquid layer height.","PeriodicalId":627,"journal":{"name":"Journal of Engineering Thermophysics","volume":"32 3","pages":"415 - 454"},"PeriodicalIF":2.4,"publicationDate":"2023-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71909214","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 and Numerical Investigation of Al2O3 Nanofluids Based Crude Oil in Shell and Tube Heat Exchanger 壳管式换热器中Al2O3纳米流体基原油的实验与数值研究

IF 2.4 4区工程技术

Journal of Engineering Thermophysics Pub Date : 2023-11-08 DOI: 10.1134/S1810232823030098

A. M. M. Al-Obaidi, M. Pirmohammadi

{"title":"Experimental and Numerical Investigation of Al2O3 Nanofluids Based Crude Oil in Shell and Tube Heat Exchanger","authors":"A. M. M. Al-Obaidi, M. Pirmohammadi","doi":"10.1134/S1810232823030098","DOIUrl":"10.1134/S1810232823030098","url":null,"abstract":"Numerical investigation of heat transfer augmentation with Al2O3 nanofluids-based crude oil in a shell and tube heat exchanger. This paper presents numerical and experimental investigations to study the effect of using Al2O3 nanofluids based crude oil on heat transfer enhancement in a turbulent regime with mass flow rate of (4 to 18 kg/s) in the shell and tube heat exchanger. The investigation concentrates on the effects of the Al2O3 based crude oil nanofluids on friction factor, flow characteristics and heat transfer, through shell and tube heat exchanger. The results show that the thermal conductivity as well as the viscosity of Al2O3 nanofluid based crude oil increased with increasing nanoparticles volume fraction and decreased with increasing the temperature. The outcomes revealed that the Nusselt number improved with increasing mass flow rate and also the friction factor increases dramatically using nanofluid this because of increment in nanofluid viscosity comparing to the base fluid (crude oil), additionally the results illustrate a constant pattern along the heat exchanger.","PeriodicalId":627,"journal":{"name":"Journal of Engineering Thermophysics","volume":"32 3","pages":"521 - 531"},"PeriodicalIF":2.4,"publicationDate":"2023-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71909651","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

Modeling of Time Pressure Profile on Sample Surface during Laser Hardening of Material 材料激光淬火过程中样品表面时间-压力分布的建模

IF 2.4 4区工程技术

Journal of Engineering Thermophysics Pub Date : 2023-11-08 DOI: 10.1134/S1810232823030165

K. E. Ulybyshev, V. V. Likhanskii, T. N. Aliev, V. G. Zborovskii, N. N. Elkin, O. V. Khoruzhii

引用次数: 0

Vacuum Plasmatrons with Hollow Cathode: Gas-Dynamic Plasma Processes in the Hollow Cathode 空心阴极真空等离子体激元：空心阴极中的气体动力学等离子体过程

IF 2.4 4区工程技术

Journal of Engineering Thermophysics Pub Date : 2023-11-08 DOI: 10.1134/S1810232823030153

P. V. Domarov, V. A. Serikov, A. E. Morev, O. S. Cherednichenko

{"title":"Vacuum Plasmatrons with Hollow Cathode: Gas-Dynamic Plasma Processes in the Hollow Cathode","authors":"P. V. Domarov, V. A. Serikov, A. E. Morev, O. S. Cherednichenko","doi":"10.1134/S1810232823030153","DOIUrl":"10.1134/S1810232823030153","url":null,"abstract":"It is shown that it is necessary for vacuum plasmatron with hollow cathode to meet the technical requirements to the hollow cathode pipeline to provide not only the necessary kinetic energy of the gas involved in the formation of working parameters in the cavity cathode but also to ensure the stable operation conditions for vacuum plasmatron at large current without the occurrence of high-frequency oscillations in the plasmatron electrical circuit. The pipeline maximum length has been established, guaranteeing the speed of gas at its final section and equals to the speed of sound at the output; the results of mathematical modeling and experimental investigated parameters for developing gas-dynamic processes in hollow cold and hot cathodes of vacuum plasmatrons are presented. The start-up modes ranges for warming up the cavity cathode and continuous discharge output with hollow cathode into working modes with flowing currents up to 10000 A are considered. The occurrence and development of the gradient pressure, density, velocity mass flow rate at heating the cathode and the gradient increase temperature effect of the cathode edge with forming current conductivity active zone in the cylindrical cathode are shown.","PeriodicalId":627,"journal":{"name":"Journal of Engineering Thermophysics","volume":"32 3","pages":"603 - 626"},"PeriodicalIF":2.4,"publicationDate":"2023-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71909576","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

Boiling Heat Transfer with Freon R-21 in Vertical Downflow for Assembly of Minichannels with Inclined Texture Freon R-21在倾斜结构微通道装配中的垂直下流沸腾传热

IF 2.4 4区工程技术

Journal of Engineering Thermophysics Pub Date : 2023-11-08 DOI: 10.1134/S1810232823030037

V. V. Kuznetsov, A. S. Shamirzaev

引用次数: 0