Pub Date : 2025-12-05DOI: 10.1016/j.ijheatfluidflow.2025.110166
Salman Akhtar , Noreen Sher Akbar , Javaria Akram , Muhammad Fiaz Hussain , Taseer Muhammad
The present research work models the blood flow inside a vertical asymmetric peristaltic domain by utilizing the non-Newtonian fluid model. We aim to examine the heat transfer characteristics of hybrid nanoparticles, electroosmosis with microbial effects, and composition of nanofluids. The non-Newtonian nature of blood flow is examined through the Johnson-Segalman model and the application of hybrid nanoparticle with electroosmosis promotes the practical biofluidic phenomenon. Moreover, this analysis illustrates the significance of microorganisms on the rheological characteristics of flow dynamics. The physical phenomenon is modeled by utilizing the governing partial differential equations that precisely illustrate the flow dynamics. We have computed numerical solutions by using finite element method that assures precise results for complex systems. The results of velocity, temperature, streamlines, micro-organisms plus nanoparticles concentration, and pressure gradient are plotted against pertinent parameters to examine their influence on blood flow rheology.
{"title":"Erratum to: heat transfer analysis on blood flow dynamics of hybrid nanoparticles in an asymmetric domain under electroosmotic and microbial effects: a Johnson-Segalman model approach","authors":"Salman Akhtar , Noreen Sher Akbar , Javaria Akram , Muhammad Fiaz Hussain , Taseer Muhammad","doi":"10.1016/j.ijheatfluidflow.2025.110166","DOIUrl":"10.1016/j.ijheatfluidflow.2025.110166","url":null,"abstract":"<div><div>The present research work models the blood flow inside a vertical asymmetric peristaltic domain by utilizing the non-Newtonian fluid model. We aim to examine the heat transfer characteristics of hybrid nanoparticles, electroosmosis with microbial effects, and composition of nanofluids. The non-Newtonian nature of blood flow is examined through the Johnson-Segalman model and the application of hybrid nanoparticle with electroosmosis promotes the practical biofluidic phenomenon. Moreover, this analysis illustrates the significance of microorganisms on the rheological characteristics of flow dynamics. The physical phenomenon is modeled by utilizing the governing partial differential equations that precisely illustrate the flow dynamics. We have computed numerical solutions by using finite element method that assures precise results for complex systems. The results of velocity, temperature, streamlines, micro-organisms plus nanoparticles concentration, and pressure gradient are plotted against pertinent parameters to examine their influence on blood flow rheology.</div></div>","PeriodicalId":335,"journal":{"name":"International Journal of Heat and Fluid Flow","volume":"118 ","pages":"Article 110166"},"PeriodicalIF":2.6,"publicationDate":"2025-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145920734","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-04DOI: 10.1016/j.ijheatfluidflow.2025.110158
Bikalpa Bomjan Gurung, Sudhir L. Gai, Amna Khraibut, Krishna M. Talluru
Comparison of the inviscid simulation and experiment data (Gai & Teh, 2000) showed the strong viscous effect of the boundary layer on the plate with separation of the boundary layer. There was a linear relationship between the inviscid and experimental data of wall pressures () measured on the symmetry plane. The effect of the interaction between the impinging shock and the trailing edge expansion fan originating from the base of the cone was to reduce the conical shock angle beginning at the expansion head. The expansion fan interaction showed strong dependency on the cone height from the plane. Separation length obtained from the experiment showed a power law dependency on for all cone angles and cone heights from the surface when normalised by the boundary layer plate thickness at the impingement location.
{"title":"Inviscid characteristics of a conical shock wave from a finite cone impinging on a flat plate in a Mach 2 flow","authors":"Bikalpa Bomjan Gurung, Sudhir L. Gai, Amna Khraibut, Krishna M. Talluru","doi":"10.1016/j.ijheatfluidflow.2025.110158","DOIUrl":"10.1016/j.ijheatfluidflow.2025.110158","url":null,"abstract":"<div><div>Comparison of the inviscid simulation and experiment data (Gai & Teh, 2000) showed the strong viscous effect of the boundary layer on the plate with separation of the boundary layer. There was a linear relationship between the inviscid and experimental data of wall pressures (<span><math><mrow><msub><mrow><mi>P</mi></mrow><mrow><mn>3</mn><mo>,</mo><mi>m</mi><mi>a</mi><mi>x</mi></mrow></msub><mo>/</mo><msub><mrow><mi>P</mi></mrow><mrow><mn>1</mn></mrow></msub></mrow></math></span>) measured on the symmetry plane. The effect of the interaction between the impinging shock and the trailing edge expansion fan originating from the base of the cone was to reduce the conical shock angle beginning at the expansion head. The expansion fan interaction showed strong dependency on the cone height from the plane. Separation length obtained from the experiment showed a power law dependency on <span><math><mrow><msub><mrow><mi>P</mi></mrow><mrow><mn>3</mn><mo>,</mo><mi>m</mi><mi>a</mi><mi>x</mi></mrow></msub><mo>/</mo><msub><mrow><mi>P</mi></mrow><mrow><mn>1</mn></mrow></msub></mrow></math></span> for all cone angles and cone heights from the surface when normalised by the boundary layer plate thickness at the impingement location.</div></div>","PeriodicalId":335,"journal":{"name":"International Journal of Heat and Fluid Flow","volume":"118 ","pages":"Article 110158"},"PeriodicalIF":2.6,"publicationDate":"2025-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145692312","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-03DOI: 10.1016/j.ijheatfluidflow.2025.110169
Yizhu Zhao , Haihua Deng , Haibao Hu , Hanbing Ke , Jun Wen , Luo Xie
To mitigate the flow-induced stress on pipe fittings that causes fatigue failure in convective heat exchangers, grooves structure are often incorporated into the surface geometry to reduce hydrodynamic forces and extend service life. To further investigate the effects of various groove structures on the hydrodynamic and heat transfer of pipe fittings, this study employs numerical simulations on fixed cylinders with different groove shapes and groove cover angles at Reynolds number of 100. The research mainly focuses on the flow and heat transfer characteristics around the cylinder. Hydrodynamic coefficients, pressure coefficients, Nusselt numbers, and flow field characteristics of the smooth cylinder and cylinders with different grooved surfaces are comparatively analyzed in this study. The results show that both different groove shapes and groove coverage rates have a significant impact on the hydrodynamic coefficients of the cylinder. Root-mean-square lift coefficient and drag coefficient of the cylinder with triangle grooves are the smallest when the cover angle is 50°, which are approximately 13% and 3.6% lower than those of the smooth cylinder, respectively. Meanwhile, its average Nusselt number is 12.14, which is only about 2.3% lower than that of the smooth cylinder.Overall, this structure offers the most outstanding performance.
{"title":"Hydrodynamic and heat transfer analysis of cylinder with different groove surfaces in laminar flow","authors":"Yizhu Zhao , Haihua Deng , Haibao Hu , Hanbing Ke , Jun Wen , Luo Xie","doi":"10.1016/j.ijheatfluidflow.2025.110169","DOIUrl":"10.1016/j.ijheatfluidflow.2025.110169","url":null,"abstract":"<div><div>To mitigate the flow-induced stress on pipe fittings that causes fatigue failure in convective heat exchangers, grooves structure are often incorporated into the surface geometry to reduce hydrodynamic forces and extend service life. To further investigate the effects of various groove structures on the hydrodynamic and heat transfer of pipe fittings, this study employs numerical simulations on fixed cylinders with different groove shapes and groove cover angles at Reynolds number of 100. The research mainly focuses on the flow and heat transfer characteristics around the cylinder. Hydrodynamic coefficients, pressure coefficients, Nusselt numbers, and flow field characteristics of the smooth cylinder and cylinders with different grooved surfaces are comparatively analyzed in this study. The results show that both different groove shapes and groove coverage rates have a significant impact on the hydrodynamic coefficients of the cylinder. Root-mean-square lift coefficient and drag coefficient of the cylinder with triangle grooves are the smallest when the cover angle is 50°, which are approximately 13% and 3.6% lower than those of the smooth cylinder, respectively. Meanwhile, its average Nusselt number is 12.14, which is only about 2.3% lower than that of the smooth cylinder.Overall, this structure offers the most outstanding performance.</div></div>","PeriodicalId":335,"journal":{"name":"International Journal of Heat and Fluid Flow","volume":"118 ","pages":"Article 110169"},"PeriodicalIF":2.6,"publicationDate":"2025-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145692363","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-03DOI: 10.1016/j.ijheatfluidflow.2025.110164
Zhimin Yao , Xiang Na , Huan Zhao , Hayder I. Mohammed , Sheng Chen
The Nusselt number, a key indicator of heat transfer around sphero-cylindrical particles in uniform flow, depends primarily on three dimensionless parameters: the aspect ratio (β), incidence angle (θ), and Reynolds number (Re). This study systematically examines the convective heat transfer of sphero-cylindrical particles using a three-dimensional Lattice Boltzmann framework. The novelty of this work lies in deriving comprehensive correlations for the Nusselt number across a wide parameter range (Re = 10–100, β = 2–8, θ = 0–90°), quantifying the dependence of the sinusoidal exponent m on Re and β—an aspect rarely addressed in previous studies—and ensuring that the proposed correlations maintain deviations below 10 %. The results show that the average Nusselt number increases monotonically with Re, reaching up to 2.5 times its value at Re = 10 when Re = 100. At Re = 30, increasing β from 2 to 8 enhances Nu by 25.3 %, while the effect levels off for β > 6. When θ increases from 0° to 60°, Nu rises by about 7.5 %, but further increases yield diminishing benefits. The derived correlations for both Nu and m achieve maximum deviations of 9.75 % and 4.3 %, respectively. By quantifying the relationships between key parameters and heat transfer characteristics, this work provides a foundation for improving the design and efficiency of systems involving sphero-cylinder particles. Ultimately, this research is essential for advancing the field of heat transfer and fluid dynamics, with potential implications for enhancing the performance and sustainability of industrial processes reliant on fluid-particle interactions.
{"title":"Enhancing heat transfer efficiency in sphero-cylinder particle systems: A numerical study","authors":"Zhimin Yao , Xiang Na , Huan Zhao , Hayder I. Mohammed , Sheng Chen","doi":"10.1016/j.ijheatfluidflow.2025.110164","DOIUrl":"10.1016/j.ijheatfluidflow.2025.110164","url":null,"abstract":"<div><div>The Nusselt number, a key indicator of heat transfer around sphero-cylindrical particles in uniform flow, depends primarily on three dimensionless parameters: the aspect ratio (<em>β</em>), incidence angle (<em>θ</em>), and Reynolds number (<em>Re</em>). This study systematically examines the convective heat transfer of sphero-cylindrical particles using a three-dimensional Lattice Boltzmann framework. The novelty of this work lies in deriving comprehensive correlations for the Nusselt number across a wide parameter range (<em>Re</em> = 10–100, <em>β</em> = 2–8, <em>θ</em> = 0–90°), quantifying the dependence of the sinusoidal exponent m on <em>Re</em> and <em>β</em>—an aspect rarely addressed in previous studies—and ensuring that the proposed correlations maintain deviations below 10 %. The results show that the average Nusselt number increases monotonically with <em>Re</em>, reaching up to 2.5 times its value at <em>Re</em> = 10 when <em>Re</em> = 100. At <em>Re</em> = 30, increasing <em>β</em> from 2 to 8 enhances <em>Nu</em> by 25.3 %, while the effect levels off for <em>β</em> > 6. When <em>θ</em> increases from 0° to 60°, <em>Nu</em> rises by about 7.5 %, but further increases yield diminishing benefits. The derived correlations for both <em>Nu</em> and m achieve maximum deviations of 9.75 % and 4.3 %, respectively. By quantifying the relationships between key parameters and heat transfer characteristics, this work provides a foundation for improving the design and efficiency of systems involving sphero-cylinder particles. Ultimately, this research is essential for advancing the field of heat transfer and fluid dynamics, with potential implications for enhancing the performance and sustainability of industrial processes reliant on fluid-particle interactions.</div></div>","PeriodicalId":335,"journal":{"name":"International Journal of Heat and Fluid Flow","volume":"118 ","pages":"Article 110164"},"PeriodicalIF":2.6,"publicationDate":"2025-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145692311","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-02DOI: 10.1016/j.ijheatfluidflow.2025.110156
J. Marroquín-Desentis , J.E. López-Escobar , S. Martínez-Delgadillo , J.A. Yañez-Varela , J.I. Hernández-Vega , A. Alonzo-García
The effect of particle curvature ratio (R*) in the turbulent flow in porous media composed of staggered cylinders was assessed. The porosity (ϕ) was varied from 0.4 to 0.8, and the R* from the square cross-section to the circular cross-section at a pore Reynolds number of Rep = 104. The Abe-Kondoh-Nagano (AKN) and the wall-modeled large eddy simulation (WMLES) techniques were used to model the turbulence. Novel insights regarding particle aerodynamics and turbulence parameters, as well as static and dynamic pressure gradients, the evolution of shear layers, and main frequencies, are described. At the lowest ϕ = 0.4, the most aerodynamic curvature was observed at R* = 0.333, where decreases of more than 60 % were achieved for the drag coefficient, friction factor, dissipation rate, and fluctuating lift. As the porosity increased, the reductions are relaxed, but still present. It is discussed that the flat regions in the upper and lower cylinder faces at R* = 0.333 act as static pressure gradient separators, thereby avoiding the sudden shock at the pore throat that is present in the circular cylinder case. Considering the advancements in additive manufacturing, this information may serve as a basis for optimizing dedicated engineering porous media devices, such as metamaterials, chemical reactors, and static mixers, among others.
{"title":"The effect of particle curvature in the turbulent flow through a porous medium composed of staggered cylinders","authors":"J. Marroquín-Desentis , J.E. López-Escobar , S. Martínez-Delgadillo , J.A. Yañez-Varela , J.I. Hernández-Vega , A. Alonzo-García","doi":"10.1016/j.ijheatfluidflow.2025.110156","DOIUrl":"10.1016/j.ijheatfluidflow.2025.110156","url":null,"abstract":"<div><div>The effect of particle curvature ratio (<em>R*</em>) in the turbulent flow in porous media composed of staggered cylinders was assessed. The porosity (<em>ϕ</em>) was varied from 0.4 to 0.8, and the <em>R*</em> from the square cross-section to the circular cross-section at a pore Reynolds number of <em>Re<sub>p</sub></em> = 10<sup>4</sup>. The Abe-Kondoh-Nagano (AKN) and the wall-modeled large eddy simulation (WMLES) techniques were used to model the turbulence. Novel insights regarding particle aerodynamics and turbulence parameters, as well as static and dynamic pressure gradients, the evolution of shear layers, and main frequencies, are described. At the lowest <em>ϕ</em> = 0.4, the most aerodynamic curvature was observed at <em>R*</em> = 0.333, where decreases of more than 60 % were achieved for the drag coefficient, friction factor, dissipation rate, and fluctuating lift. As the porosity increased, the reductions are relaxed, but still present. It is discussed that the flat regions in the upper and lower cylinder faces at <em>R*</em> = 0.333 act as static pressure gradient separators, thereby avoiding the sudden shock at the pore throat that is present in the circular cylinder case. Considering the advancements in additive manufacturing, this information may serve as a basis for optimizing dedicated engineering porous media devices, such as metamaterials, chemical reactors, and static mixers, among others.</div></div>","PeriodicalId":335,"journal":{"name":"International Journal of Heat and Fluid Flow","volume":"118 ","pages":"Article 110156"},"PeriodicalIF":2.6,"publicationDate":"2025-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145692368","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-02DOI: 10.1016/j.ijheatfluidflow.2025.110159
Mario Misale, Annalisa Marchitto, Johan Augusto Bocanegra
Significant research efforts are being carried out in this century to reduce the environmental impact of energy production and transportation technologies. The greenhouse effect caused an increase in the average temperature, and one of the targets is to keep it below two degrees Celsius. An interesting technology for transferring thermal energy without active devices (such as a pump or blower) is natural circulation in loops. These thermal circuits find applications in various engineering fields, such as geothermal implants, the cooling of new-generation nuclear reactors, electronic components, and solar systems. This paper presents an experimental study of natural circulation in interconnected loops. In particular, thermo-hydraulic behavior is studied when different parameters, such as power transferred to the fluid and the inclination of the entire loop assembly (referred to as the gravitational field), change. The interaction between multi-connected loops was observed for the first time, showing a direct dependence on the inclination angle and the input power differences of the three circuits. The maximum temperature difference and interaction intensity were observed at the higher inclination angle of 60°.
{"title":"New aspects in thermal systems at low ambient impact: Experimental study on interconnected natural circulation loops","authors":"Mario Misale, Annalisa Marchitto, Johan Augusto Bocanegra","doi":"10.1016/j.ijheatfluidflow.2025.110159","DOIUrl":"10.1016/j.ijheatfluidflow.2025.110159","url":null,"abstract":"<div><div>Significant research efforts are being carried out in this century to reduce the environmental impact of energy production and transportation technologies. The greenhouse effect caused an increase in the average temperature, and one of the targets is to keep it below two degrees Celsius. An interesting technology for transferring thermal energy without active devices (such as a pump or blower) is natural circulation in loops. These thermal circuits find applications in various engineering fields, such as geothermal implants, the cooling of new-generation nuclear reactors, electronic components, and solar systems. This paper presents an experimental study of natural circulation in interconnected loops. In particular, thermo-hydraulic behavior is studied when different parameters, such as power transferred to the fluid and the inclination of the entire loop assembly (referred to as the gravitational field), change. The interaction between multi-connected loops was observed for the first time, showing a direct dependence on the inclination angle and the input power differences of the three circuits. The maximum temperature difference and interaction intensity were observed at the higher inclination angle of 60°.</div></div>","PeriodicalId":335,"journal":{"name":"International Journal of Heat and Fluid Flow","volume":"118 ","pages":"Article 110159"},"PeriodicalIF":2.6,"publicationDate":"2025-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145692369","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-01DOI: 10.1016/j.ijheatfluidflow.2025.110165
Yu Feng , Zhenhua Wang , Jiang Qin , Fuqiang Chen
Thermal cracking of hydrocarbon fuels serves as a thermal management method for hypersonic vehicles, yet it faces challenges of insufficient cooling capacity and pyrolytic coking at high Mach numbers (Ma > 7). The steam reforming of hydrocarbon fuels is effective in improving heat sink and inhibiting coke formation. This study experimentally explores the effects of water content, mass flow rate, and pressure on heat sink distribution in different temperatures, with gaseous yield analysis revealing the mechanistic effects of steam reforming reactions in heat sink enhancement. The results indicate that the initial temperature of steam reforming reaction (360 ℃) is considerably lower than the temperature for thermal cracking reaction (490 ℃), implying an earlier release of the chemical heat sink. The higher water-content exhibits higher total heat sink in the low-temperature stage. In the high-temperature stage, the reaction path and carbon molar yield are affected by the various water contents, and the high water-content promotes the steam reforming reaction and reduces the production of coking precursor olefins. The mass flow rate primarily affects carbon molar yield by modifying reaction duration, while exerting negligible influence on the reaction pathways. High-pressure conditions accelerate the frequency of intermolecular collisions thereby facilitating the release of chemical heat sinks. This study is expected to provide both experimental data and theoretical guidance for the application of steam reforming in cooling channels of scramjet.
{"title":"Experimental investigation on heat sink distribution of regenerative cooling with supercritical n-decane catalytic steam reforming","authors":"Yu Feng , Zhenhua Wang , Jiang Qin , Fuqiang Chen","doi":"10.1016/j.ijheatfluidflow.2025.110165","DOIUrl":"10.1016/j.ijheatfluidflow.2025.110165","url":null,"abstract":"<div><div>Thermal cracking of hydrocarbon fuels serves as a thermal management method for hypersonic vehicles, yet it faces challenges of insufficient cooling capacity and pyrolytic coking at high Mach numbers (Ma > 7). The steam reforming of hydrocarbon fuels is effective in improving heat sink and inhibiting coke formation. This study experimentally explores the effects of water content, mass flow rate, and pressure on heat sink distribution in different temperatures, with gaseous yield analysis revealing the mechanistic effects of steam reforming reactions in heat sink enhancement. The results indicate that the initial temperature of steam reforming reaction (360 ℃) is considerably lower than the temperature for thermal cracking reaction (490 ℃), implying an earlier release of the chemical heat sink. The higher water-content exhibits higher total heat sink in the low-temperature stage. In the high-temperature stage, the reaction path and carbon molar yield are affected by the various water contents, and the high water-content promotes the steam reforming reaction and reduces the production of coking precursor olefins. The mass flow rate primarily affects carbon molar yield by modifying reaction duration, while exerting negligible influence on the reaction pathways. High-pressure conditions accelerate the frequency of intermolecular collisions thereby facilitating the release of chemical heat sinks. This study is expected to provide both experimental data and theoretical guidance for the application of steam reforming in cooling channels of scramjet.</div></div>","PeriodicalId":335,"journal":{"name":"International Journal of Heat and Fluid Flow","volume":"118 ","pages":"Article 110165"},"PeriodicalIF":2.6,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145692307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In recent years, advancements in thermoelectric materials have substantially increased the application potential of thermoelectric cooling technology. As the primary energy conversion unit in thermoelectric cooling systems, the performance of the thermoelectric cooling unit (TECU) has a direct impact on system efficiency and reliability. However, current designs of TECU are limited owing to a lack of standardized procedures. Moreover, existing research has primarily focused on heat transfer processes, while the impact of condensation from humid air on the cold-side during practical operation remains largely unexplored. This study proposes a systematic design process based on rated cooling capacity and designs a TECU with a cooling capacity of 500 W. Subsequently, a coupled simulation model integrating “thermoelectric effects–heat transfer–heat-mass conversion” is developed to investigate the thermal and humidity characteristics of thermoelectric cooling performance. Simulation results show a linear relationship between temperature and cooling performance. A 2 ℃ increase in cold-side temperature increases cooling capacity by 32.3 W, while an equivalent increase in hot-side temperature reduces it by 26.2 W. By contrast, the effect of humidity is non-linear and complex. Humidity only affects the cooling performance once it reaches the condensation threshold. The condensation phenomenon improves heat transfer efficiency and increases cooling capacity by an average of 64.3 W. Under varying temperature and humidity working conditions, the TECU maintains a constant cooling capacity of 500 W by adjusting the TECU input current. Notably, the coefficient of performance improves by 61.0 % under high-humidity conditions, reaching 1.41. This study provides valuable theoretical insights for the design and application of TECU.
{"title":"Design and thermal-humidity characteristics of a thermoelectric cooling unit","authors":"Ding Wang, Wenqian Zhang, Leyao Chu, Zun Liu, Limei Shen","doi":"10.1016/j.ijheatfluidflow.2025.110168","DOIUrl":"10.1016/j.ijheatfluidflow.2025.110168","url":null,"abstract":"<div><div>In recent years, advancements in thermoelectric materials have substantially increased the application potential of thermoelectric cooling technology. As the primary energy conversion unit in thermoelectric cooling systems, the performance of the thermoelectric cooling unit (TECU) has a direct impact on system efficiency and reliability. However, current designs of TECU are limited owing to a lack of standardized procedures. Moreover, existing research has primarily focused on heat transfer processes, while the impact of condensation from humid air on the cold-side during practical operation remains largely unexplored. This study proposes a systematic design process based on rated cooling capacity and designs a TECU with a cooling capacity of 500 W. Subsequently, a coupled simulation model integrating “thermoelectric effects–heat transfer–heat-mass conversion” is developed to investigate the thermal and humidity characteristics of thermoelectric cooling performance. Simulation results show a linear relationship between temperature and cooling performance. A 2 ℃ increase in cold-side temperature increases cooling capacity by 32.3 W, while an equivalent increase in hot-side temperature reduces it by 26.2 W. By contrast, the effect of humidity is non-linear and complex. Humidity only affects the cooling performance once it reaches the condensation threshold. The condensation phenomenon improves heat transfer efficiency and increases cooling capacity by an average of 64.3 W. Under varying temperature and humidity working conditions, the TECU maintains a constant cooling capacity of 500 W by adjusting the TECU input current. Notably, the coefficient of performance improves by 61.0 % under high-humidity conditions, reaching 1.41. This study provides valuable theoretical insights for the design and application of TECU.</div></div>","PeriodicalId":335,"journal":{"name":"International Journal of Heat and Fluid Flow","volume":"118 ","pages":"Article 110168"},"PeriodicalIF":2.6,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145692370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-29DOI: 10.1016/j.ijheatfluidflow.2025.110162
Kong Mingjuan , Zhu Tong , Wang Lu , Chi Ying
This study investigates the role of wall film models in the simulation of spray humidification processes, focusing on their impact on fluid dynamics and heat transfer phenomena. The research explores the application of wall film models and their optimization parameters, as well as the differences in spray droplet motion, evaporation, and distribution. A comprehensive analysis is conducted on the characteristics and applicability of wall film models, including the Lagrangian Wall Film (LWF) model within the discrete phase model, the Eulerian Wall Film (EWF) model, and the EWF coupled with the Volume of Fluid (VOF) model, from both mathematical and physical perspectives. Numerical simulation experiments are employed to compare the effects of these models on the evaporation rate, distribution pattern, and humidification effectiveness of spray droplets. Additionally, the performance under identical conditions with varying spray droplet sizes is examined. The study concludes with a synthesis of the advantages and disadvantages of each model, offering a theoretical foundation and technical support for the enhancement of spray humidification processes.
{"title":"The influence of different wall film models on the simulation of spray humidification process","authors":"Kong Mingjuan , Zhu Tong , Wang Lu , Chi Ying","doi":"10.1016/j.ijheatfluidflow.2025.110162","DOIUrl":"10.1016/j.ijheatfluidflow.2025.110162","url":null,"abstract":"<div><div>This study investigates the role of wall film models in the simulation of spray humidification processes, focusing on their impact on fluid dynamics and heat transfer phenomena. The research explores the application of wall film models and their optimization parameters, as well as the differences in spray droplet motion, evaporation, and distribution. A comprehensive analysis is conducted on the characteristics and applicability of wall film models, including the Lagrangian Wall Film (LWF) model within the discrete phase model, the Eulerian Wall Film (EWF) model, and the EWF coupled with the Volume of Fluid (VOF) model, from both mathematical and physical perspectives. Numerical simulation experiments are employed to compare the effects of these models on the evaporation rate, distribution pattern, and humidification effectiveness of spray droplets. Additionally, the performance under identical conditions with varying spray droplet sizes is examined. The study concludes with a synthesis of the advantages and disadvantages of each model, offering a theoretical foundation and technical support for the enhancement of spray humidification processes.</div></div>","PeriodicalId":335,"journal":{"name":"International Journal of Heat and Fluid Flow","volume":"118 ","pages":"Article 110162"},"PeriodicalIF":2.6,"publicationDate":"2025-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145623273","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-26DOI: 10.1016/j.ijheatfluidflow.2025.110153
Xuan-Kai Zhang , Xu Cheng , Zuan-Si Cai , Tian-Run Yang , Mu Du , Zi-Zhen Lin
In this study, a validated coupled mathematical model integrating electromagnetics, thermodynamics, and fluid mechanics is developed, innovatively employing the thermal-flow field synergy principle to diagnose the LA’s performance. According to the conclusion, the LA is an intrinsically inefficient system is firstly revealed; despite a high-energy core concentrated near the cathode, the thermal-flow synergy angle (β) of LA in the furnace is remarkably high, indicating poor convective heat transfer and substantial energy loss. Consequently, the baseline energy efficiency (η) is only 29.2 % under typical condition of electrode current (I) = 12.5 kA and arc length (L) = 200 mm. The conventional control strategies, adjusting I or L, are then demonstrated, which leads to a fundamental power-efficiency paradox. Increasing I or L boosts arc power (QArc) but invariably decreases η. The peak QArc of 3.8 MW (at 15.0 kA, 250 mm) and the peak η of 33.4 % (at 10.0 kA, 150 mm) occur at opposite ends of the operational spectrum, defining a clear performance trade-off. To transcend this impasse, the “Ordered Heat Transfer” concept is proposed in this paper for LA in EAF as a new paradigm, aimed at simultaneously enhancing QArc and η by strategically managing convective energy pathways. Finally, multiple regression equations are established to accurately predict anode energy fluxes, providing a valuable tool for industrial process optimization.
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