Journal of Engineering Thermophysics最新文献

Prediction of Void Fraction in Sub-Cooled Flow Boiling at High Pressure Using Distribution Parameter Correlations

IF 1.3 4区工程技术

Journal of Engineering Thermophysics Pub Date : 2025-04-18 DOI: 10.1134/S1810232825010126

C. J. Odii, A. G. Korotkikh

{"title":"Prediction of Void Fraction in Sub-Cooled Flow Boiling at High Pressure Using Distribution Parameter Correlations","authors":"C. J. Odii, A. G. Korotkikh","doi":"10.1134/S1810232825010126","DOIUrl":"10.1134/S1810232825010126","url":null,"abstract":"In this work, the void fraction based on the Zuber and Findlay model is evaluated at onset of nucleate boiling (ONB) using the Delhaye et al expression of true quality and onset of significant void (OSV) using the Manon expression of true quality. The distribution parameter correlations of Hancox–Nicoll, Nabizadeh, DIX and a data fitting distribution parameter correlation from the DEBORA experiment which was extended for light water were considered. The numerical modeling of the forced convective subcooled boiling water was done at the pressures and mass fluxes of 12.5 MPa and 2800 kg m(^{-2}) s(^{-1}), 15.7 MPa and 3600 kg m(^{-2}) s(^{-1}), and 16.2 MPa and 3836 kg m(^{-2}) s(^{-1}), respectively, corresponding to the operating parameters of pressurized water reactors (PWRs). The result of the calculation indicates that the Dix and Nabizadeh distribution parameters highly deviated from the DEBORA fitted data prediction at the pressure and mass flux range used, and both distribution parameters almost overlapped in their prediction of void fraction at 16.2 MPa. Within the pressure and mass flux range used for this calculation, the Hancox and Nicoll distribution parameter predicted void fraction were below the DEBORA fitted data prediction and deviation increased as pressure and mass flux decreased.","PeriodicalId":627,"journal":{"name":"Journal of Engineering Thermophysics","volume":"34 1","pages":"133 - 149"},"PeriodicalIF":1.3,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143848923","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

On Universal Velocity Profile of Turbulent Flow in Round Pipe

IF 1.3 4区工程技术

Journal of Engineering Thermophysics Pub Date : 2025-04-18 DOI: 10.1134/S1810232825010047

N. I. Yavorsky

引用次数: 0

Influence of Optical Properties of Two-Phase Medium on Intensity of Melting of Layer of Cloudy Ice

IF 1.3 4区工程技术

Journal of Engineering Thermophysics Pub Date : 2025-04-18 DOI: 10.1134/S1810232825010096

S. D. Sleptsov, N. A. Savvinova

引用次数: 0

Experiments on Condensation Heat Transfer and Frictional Pressure Drop of Zeotropic Mixtures R245fa/R1234ze(E) Inside Horizontal Micro-Fin Tubes

IF 1.3 4区工程技术

Journal of Engineering Thermophysics Pub Date : 2025-04-18 DOI: 10.1134/S1810232825010138

Y. Liu

{"title":"Experiments on Condensation Heat Transfer and Frictional Pressure Drop of Zeotropic Mixtures R245fa/R1234ze(E) Inside Horizontal Micro-Fin Tubes","authors":"Y. Liu","doi":"10.1134/S1810232825010138","DOIUrl":"10.1134/S1810232825010138","url":null,"abstract":"This study addresses the urgent need to reduce greenhouse gases by investigating high-temperature heat pump systems and binary organic Rankine cycle generators that utilize low-temperature industrial waste heat. Traditionally, R245fa has been used in these systems due to its low working pressure and high critical temperature. However, its high Global Warming Potential necessitates a transition to alternative refrigerants. This research focuses on the heat transfer and pressure drop characteristics of the R245fa/R1234ze(E) refrigerant mixture, a promising alternative with a lower GWP. Experiments were conducted using horizontal micro-fin tubes with copper test tubes of 9.52 mm outer diameter, varying fin heights and numbers, under mass velocities of 100 and 200 kgm(^{-2})s(^{-1}) and mass fractions of 90/10, 80/20, and 65/35 (R245fa/R1234ze(E)) at an average saturation temperature of 60°C. The results showed that the R245fa/R1234ze(E) mixture had lower condensation heat transfer coefficients and frictional pressure drops compared to pure R245fa. The minimum heat transfer coefficient occurred at a 65/35 mass % mass mixture, which is close to the point where the largest temperature glide appeared. Additionally, the frictional pressure drop decreased with increasing mass fractions of R1234ze(E). These findings suggest that the R245fa/R1234ze(E) mixture, despite its lower heat transfer performance compared to pure R245fa, presents a viable lower-GWP alternative for high-temperature heat pump and binary generation systems. This contributes to the development of more efficient and environmentally friendly refrigerant systems, supporting global efforts to reduce greenhouse gas emissions. Further research is needed to optimize the performance of these mixtures in practical applications.","PeriodicalId":627,"journal":{"name":"Journal of Engineering Thermophysics","volume":"34 1","pages":"150 - 161"},"PeriodicalIF":1.3,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143848924","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

Study on the Effect of Equal Volume Filled Copper Foam on Radiator Temperature

IF 1.3 4区工程技术

Journal of Engineering Thermophysics Pub Date : 2025-04-18 DOI: 10.1134/S1810232825010163

Z. Zhang, S. Q. Wang, S. Mehendale, J. J. Tian

{"title":"Study on the Effect of Equal Volume Filled Copper Foam on Radiator Temperature","authors":"Z. Zhang, S. Q. Wang, S. Mehendale, J. J. Tian","doi":"10.1134/S1810232825010163","DOIUrl":"10.1134/S1810232825010163","url":null,"abstract":"In this study, copper foam with varying filling rates (porosity of 95% and pore density of 20 ppi) was combined with paraffin wax and integrated into a heat sink to investigate temperature fluctuations within the heat sink after charging and discharging of copper foam phase change materials (PCM) and an empty heat sink with varying filling rates. The study focused on three key PCMs: RT-42HC, RT-50HC, and RT-60HC. The PCMs had copper foam filling ratios of (psi=0.18), (psi=0.37), and (psi=0.55), with three heating loads (0.9 kW/m2, 1.8 kW/m2, and 2.7 kW/m2). The data suggest that after 90 minutes of charging, RT-42HC ((psi=0.37)) can decrease the baseline temperature by 20.29% at 0.9 kW/m2 and a maximum of 35.49% with a foam filling ratio of (psi=0.18). Under a heating load of 2.7 kW/m2, RT-50HC ((psi=0.18)) can reduce the baseline temperature by up to 35.49%. At the same load, RT-50HC ((psi=0.18)) can reduce the reference temperature by 32.45%.RT-42HC ((psi=0.55)) has a maximum enhancement ratio of 4.38 at SPT = 50° and a heating load of 18 W, whereas RT-50HC ((psi=0.55)) has a maximum enhancement ratio of 4.3 at SPT=60° and a load of 27 W. In the cycle test with an 18 W heating load, RT-42HC ((psi=0.37)) had the most favorable influence, lowering the reference temperature by a maximum of 21.94%.","PeriodicalId":627,"journal":{"name":"Journal of Engineering Thermophysics","volume":"34 1","pages":"208 - 226"},"PeriodicalIF":1.3,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143848974","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

Numerical Investigation of Hybrid TiO2-Water Nano-Fluid with Heat Source and Induced Magnetic Field

IF 1.3 4区工程技术

Journal of Engineering Thermophysics Pub Date : 2025-04-18 DOI: 10.1134/S1810232825010175

Pratibha Bhoi, Arjun Agrawal, J. P. Panda

引用次数: 0

Using CO2 Hydrate and Air Flow to Extinguish Flame from Wood Materials

IF 1.3 4区工程技术

Journal of Engineering Thermophysics Pub Date : 2025-04-18 DOI: 10.1134/S1810232825010060

S. Y. Misyura, V. S. Morozov, P. A. Strizhak

引用次数: 0

Experimental Study of Flame Combustion of Pulverized Coal Fuel in a Two-Stage Vortex Burner

IF 1.3 4区工程技术

Journal of Engineering Thermophysics Pub Date : 2025-04-18 DOI: 10.1134/S1810232825010084

E. Yu. Gorelikov, I. V. Litvinov, E. B. Butakov, S. I. Shtork

{"title":"Experimental Study of Flame Combustion of Pulverized Coal Fuel in a Two-Stage Vortex Burner","authors":"E. Yu. Gorelikov, I. V. Litvinov, E. B. Butakov, S. I. Shtork","doi":"10.1134/S1810232825010084","DOIUrl":"10.1134/S1810232825010084","url":null,"abstract":"The paper presents a study of the aerodynamics of flame combustion of coal fuel in a burner device with thermal power of 50 kW. The burner device was a two-stage tangential swirler. In the first stage, air was supplied tangentially with axial pilot supply of propane. In the second stage, the pulverized coal mixture with heated secondary air was supplied. During the experiments, the efficiency of coal fuel combustion was studied with co-swirl and counter-swirl of the second stage relatively to the first one. The temperature was measured on the wall and in the center along the muffle swirl chamber. The gas composition of the combustion products was measured at the outlet of the swirl chamber. The profiles of the mean axial and tangential velocity along the length of the swirl chamber were measured with the two-component laser Doppler anemometer (LDA) system. Particles of unburned coal fuel served as signal tracers. The obtained results have led to a conclusion about the efficiency of the system for pulverized coal fuel combustion in the counter-swirl mode for enhancement of mixing and combustion.","PeriodicalId":627,"journal":{"name":"Journal of Engineering Thermophysics","volume":"34 1","pages":"84 - 92"},"PeriodicalIF":1.3,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143848907","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 Graphene Nanotubes on Thermal Conductivity of a Phase Change Material

IF 1.3 4区工程技术

Journal of Engineering Thermophysics Pub Date : 2025-04-18 DOI: 10.1134/S1810232825010114

M. I. Nizovtsev, V. N. Letushko, A. N. Sterlyagov

{"title":"Effect of Graphene Nanotubes on Thermal Conductivity of a Phase Change Material","authors":"M. I. Nizovtsev, V. N. Letushko, A. N. Sterlyagov","doi":"10.1134/S1810232825010114","DOIUrl":"10.1134/S1810232825010114","url":null,"abstract":"The paper presents experimental results on the use of graphene nanotubes aimed at an increase in thermal conductivity of a phase change material. Graphene nanotubes were dispersed in molten paraffin by ultrasonic treatment in an amount of 0.1–0.5 wt. %. The obtained samples of paraffin with graphene nanotubes were examined using a scanning calorimeter. During heating and cooling, the DSC curves of all samples with different content of nanotubes demonstrated two peaks corresponding to phase transitions of the main hydrocarbons in paraffin composition. The presence of nanotubes in paraffin did not significantly affect the shape of the DSC curves. Experiments with sample heating in a thermostat in terms of a time delay in changing the temperature of samples indicated an increase in thermal conductivity of solid paraffin with addition of graphene nanotubes and its decrease, when graphene nanotubes were added to liquid paraffin. These effects increased with increasing mass content of nanotubes. The method of steady-state heat flux was used to determine the coefficient of thermal conductivity of samples of a phase change material with nanotubes. According to the measurement results, the maximum increase in the thermal conductivity of paraffin in the solid state was 22% at a nanotube concentration of 0.5 wt. %. The thermal conductivity coefficients of various materials with “contrasting” inclusions were compared according to the results of calculations and experiments.","PeriodicalId":627,"journal":{"name":"Journal of Engineering Thermophysics","volume":"34 1","pages":"121 - 132"},"PeriodicalIF":1.3,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143848922","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

HFE-7100 Droplet Interaction with a Superheated Surface

IF 1.3 4区工程技术

Journal of Engineering Thermophysics Pub Date : 2025-04-18 DOI: 10.1134/S1810232825010072

V. O. Sitnikov, E. Ya. Gatapova

引用次数: 0