Pub Date : 2026-01-23DOI: 10.1016/j.icheatmasstransfer.2026.110531
Lixing Zhou
Large-eddy simulation (LES) is presently used in modeling of turbulent flames. The key problems are sub-grid scale (SGS) stress and combustion models. Up to now many investigators used different combustion models. However, some models are good only for certain flame types (premixed or non-premixed flames) and certain flame structures (wrinkled flame, corrugated flame, broken reaction zones etc.), or computationally very expensive. Reliable, general and economic models for engineering application remain to be developed. In this paper, the description of a dynamic second-order moment (DSOM) and a direct moment closure (DMC) combustion model, their application in LES of turbulent flames, validation by experiments and direct numerical simulation (DNS), and corresponding instantaneous flame structures are reported.
{"title":"Dynamic second-order-moment and direct-moment closure combustion models for large-eddy simulation of gas/spray flames-a review","authors":"Lixing Zhou","doi":"10.1016/j.icheatmasstransfer.2026.110531","DOIUrl":"10.1016/j.icheatmasstransfer.2026.110531","url":null,"abstract":"<div><div>Large-eddy simulation (LES) is presently used in modeling of turbulent flames. The key problems are sub-grid scale (SGS) stress and combustion models. Up to now many investigators used different combustion models. However, some models are good only for certain flame types (premixed or non-premixed flames) and certain flame structures (wrinkled flame, corrugated flame, broken reaction zones etc.), or computationally very expensive. Reliable, general and economic models for engineering application remain to be developed. In this paper, the description of a dynamic second-order moment (DSOM) and a direct moment closure (DMC) combustion model, their application in LES of turbulent flames, validation by experiments and direct numerical simulation (DNS), and corresponding instantaneous flame structures are reported.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"172 ","pages":"Article 110531"},"PeriodicalIF":6.4,"publicationDate":"2026-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146022699","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2026-01-23DOI: 10.1016/j.icheatmasstransfer.2026.110585
Baoyi Hu , Guofu Chen , Kun Wang , Zhaoliang Wang
Thermal rectification is a phenomenon with significant implications for thermal management and energy conversion technologies. In this work, a Monte Carlo solution of the Boltzmann Transport Equation is employed to investigate radial thermal rectification in GaN nanowire-based core-shell nanostructure. The study shows that heat preferentially flows from the inner heat source to the outer one, and the thermal rectification ratio increases with the core radius. At a radius of 36 nm, the thermal rectification ratio reaches 23.9%. The emergence of thermal rectification is mainly due to the presence of interface and asymmetric structure. The study highlights the role of interfacial scattering in enhancing asymmetric phonon transport, leading to non-linear temperature distributions and significant interfacial thermal rectification. Phonons with long mean free paths are particularly affected by interfacial scattering, while phonons with short mean free paths are increasingly influenced by the increase in radius, ultimately exacerbating interfacial thermal rectification. This study provides valuable insights for the design of thermal rectification devices and contributes to understanding heat transfer in nanoscale heterogeneous structures.
{"title":"Radius-enhanced interfacial thermal rectification in GaN nanowire-based core-shell nanostructure","authors":"Baoyi Hu , Guofu Chen , Kun Wang , Zhaoliang Wang","doi":"10.1016/j.icheatmasstransfer.2026.110585","DOIUrl":"10.1016/j.icheatmasstransfer.2026.110585","url":null,"abstract":"<div><div>Thermal rectification is a phenomenon with significant implications for thermal management and energy conversion technologies. In this work, a Monte Carlo solution of the Boltzmann Transport Equation is employed to investigate radial thermal rectification in GaN nanowire-based core-shell nanostructure. The study shows that heat preferentially flows from the inner heat source to the outer one, and the thermal rectification ratio increases with the core radius. At a radius of 36 nm, the thermal rectification ratio reaches 23.9%. The emergence of thermal rectification is mainly due to the presence of interface and asymmetric structure. The study highlights the role of interfacial scattering in enhancing asymmetric phonon transport, leading to non-linear temperature distributions and significant interfacial thermal rectification. Phonons with long mean free paths are particularly affected by interfacial scattering, while phonons with short mean free paths are increasingly influenced by the increase in radius, ultimately exacerbating interfacial thermal rectification. This study provides valuable insights for the design of thermal rectification devices and contributes to understanding heat transfer in nanoscale heterogeneous structures.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"172 ","pages":"Article 110585"},"PeriodicalIF":6.4,"publicationDate":"2026-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146022695","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2026-01-22DOI: 10.1016/j.icheatmasstransfer.2026.110584
Shili Lin, Mingbiao Chen
Deep understanding of ice nucleation in supercooled water is crucial for advancing technologies such as anti-icing of airplanes, ice making of supercooled water and organ preservation. However, the combined effects of both shear and temperature gradient in the near-wall region are frequently overlooked, leading to significant discrepancies in predictions and a severe effect on the application of the technologies. Here, we proposed an ice nucleation model considering the rebounded deformation energy and temperature gradient to analyze the ice nucleation in the near-wall region. It was found that: (1) The critical nucleus radius is the central parameter through which shear rate and temperature gradient exhibit competitive interplay. (2) The competition creates a scale effect that regulates nucleation sensitivity. A larger critical nucleus radius amplifies the nucleus's perception of the temperature gradient. (3) Compared to the thermodynamic term ratio, the nucleation rate ratio followed a similar trend in response to changes in temperature gradient.
{"title":"Ice nucleation of supercooled water in the near-wall region","authors":"Shili Lin, Mingbiao Chen","doi":"10.1016/j.icheatmasstransfer.2026.110584","DOIUrl":"10.1016/j.icheatmasstransfer.2026.110584","url":null,"abstract":"<div><div>Deep understanding of ice nucleation in supercooled water is crucial for advancing technologies such as anti-icing of airplanes, ice making of supercooled water and organ preservation. However, the combined effects of both shear and temperature gradient in the near-wall region are frequently overlooked, leading to significant discrepancies in predictions and a severe effect on the application of the technologies. Here, we proposed an ice nucleation model considering the rebounded deformation energy and temperature gradient to analyze the ice nucleation in the near-wall region. It was found that: (1) The critical nucleus radius is the central parameter through which shear rate and temperature gradient exhibit competitive interplay. (2) The competition creates a scale effect that regulates nucleation sensitivity. A larger critical nucleus radius amplifies the nucleus's perception of the temperature gradient. (3) Compared to the thermodynamic term ratio, the nucleation rate ratio followed a similar trend in response to changes in temperature gradient.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"172 ","pages":"Article 110584"},"PeriodicalIF":6.4,"publicationDate":"2026-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146022401","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2026-01-22DOI: 10.1016/j.icheatmasstransfer.2026.110581
Peng Pan , Kai-Xin Di , Li-Ke Niu
Despite their widespread application in heat exchange systems, vortex tubes were limited by their inadequate cooling and heating efficiency. Hence, the novel helical internals were designed and integrated into the vortex tube to enhance its performance. The characteristics of temperature separation in an innovative vortex tube were assessed employing numerical methods, and results indicated that under an inlet mass flow rate of 0.004 kg/s and a cold mass fraction ranging from 0.1 to 0.9, the cooling effect was further increased by 4.93 K, while the heating effect was improved by 1.68 K, compared to conventional vortex tubes. The performance enhancement was attributed to the effective flow field regulation achieved through the introduction of helical internals. Additionally, a highly accurate predictive model was developed based on regression analysis, which provided a reliable tool for the engineering application of vortex tube technology.
{"title":"Numerical investigation on the performance enhancement of vortex tubes incorporating innovative helical internals","authors":"Peng Pan , Kai-Xin Di , Li-Ke Niu","doi":"10.1016/j.icheatmasstransfer.2026.110581","DOIUrl":"10.1016/j.icheatmasstransfer.2026.110581","url":null,"abstract":"<div><div>Despite their widespread application in heat exchange systems, vortex tubes were limited by their inadequate cooling and heating efficiency. Hence, the novel helical internals were designed and integrated into the vortex tube to enhance its performance. The characteristics of temperature separation in an innovative vortex tube were assessed employing numerical methods, and results indicated that under an inlet mass flow rate of 0.004 kg/s and a cold mass fraction ranging from 0.1 to 0.9, the cooling effect was further increased by 4.93 K, while the heating effect was improved by 1.68 K, compared to conventional vortex tubes. The performance enhancement was attributed to the effective flow field regulation achieved through the introduction of helical internals. Additionally, a highly accurate predictive model was developed based on regression analysis, which provided a reliable tool for the engineering application of vortex tube technology.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"172 ","pages":"Article 110581"},"PeriodicalIF":6.4,"publicationDate":"2026-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146022402","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2026-01-22DOI: 10.1016/j.icheatmasstransfer.2026.110554
Chen Sun , Ren Dai , Leren Tao , Cheng Jin , Wanying Chang , Peiyu Liu , Zheming Cheng
Two-phase flow boiling experiment has conducted in a visual vertically upward narrow rectangular channel featuring unilaterally electric heating. The geometric dimension of the channel is 686 mm × 216 mm × 2.75 mm (l × w × s), using deionized water as the working medium. The experiment was carried out under atmospheric pressure, covering the range in inlet temperature of 50–90 °C, mass flux of 4.04–24.24 kg/(m2·s), and heat flux of 6.41–48.08 kW/m2. A high-speed photography was used to classified the flow patterns and flow regimes in each stage and analyze the corresponding local and average heat transfer characteristics. The results indicate that a secondary enhancement in heat transfer during the transition from convective boiling (CB) to the film evaporation (FE) mechanism. The wall superheat at onset of film evaporation (ONB), onset of fully developed boiling (OFDB), and onset of film evaporation (OFE) exhibited a strong positive correlation with heat flux, while the influences of inlet temperature and mass flux were negligible. The average HTC in the narrow channel is dictated by the flow regime distribution. A comprehensive evaluation of numerous predictive models for thermal-hydraulic thresholds and heat transfer coefficients was conducted. New correlations for ONB, OFDB, OFE, and average HTC were developed and demonstrated excellent predictive accuracy, with mean relative errors (MRE) of −2.71%, −2.80%, 3.25%, and 0.19%, respectively.
在单向电加热的垂直向上的窄矩形通道内进行了两相流沸腾实验。通道几何尺寸为686 mm × 216 mm × 2.75 mm (l × w × s)，以去离子水为工质。实验在常压下进行，入口温度50 ~ 90℃，质量通量4.04 ~ 24.24 kg/(m2·s)，热流通量6.41 ~ 48.08 kW/m2。采用高速摄影技术对各阶段的流态和流型进行了分类，并分析了相应的局部和平均换热特性。结果表明，在从对流沸腾（CB）过渡到膜蒸发（FE）的过程中，传热发生了二次强化。膜蒸发起始壁面过热度（ONB）、完全沸腾起始时间（OFDB）和膜蒸发起始时间（OFE）与热流密度呈显著正相关，进口温度和质量流密度的影响可以忽略不计。窄通道中的平均HTC由流态分布决定。对众多的热液阈值和传热系数预测模型进行了综合评价。建立了ONB、OFDB、OFE和平均HTC的新相关性，并证明了良好的预测准确性，平均相对误差（MRE）分别为- 2.71%、- 2.80%、3.25%和0.19%。
{"title":"Experimental study on boiling heat transfer characteristics and thermal-hydraulic thresholds in a vertical upward rectangular narrow channel","authors":"Chen Sun , Ren Dai , Leren Tao , Cheng Jin , Wanying Chang , Peiyu Liu , Zheming Cheng","doi":"10.1016/j.icheatmasstransfer.2026.110554","DOIUrl":"10.1016/j.icheatmasstransfer.2026.110554","url":null,"abstract":"<div><div>Two-phase flow boiling experiment has conducted in a visual vertically upward narrow rectangular channel featuring unilaterally electric heating. The geometric dimension of the channel is 686 mm × 216 mm × 2.75 mm (<em>l</em> × <em>w</em> × <em>s</em>), using deionized water as the working medium. The experiment was carried out under atmospheric pressure, covering the range in inlet temperature of 50–90 °C, mass flux of 4.04–24.24 kg/(m<sup>2</sup>·s), and heat flux of 6.41–48.08 kW/m<sup>2</sup>. A high-speed photography was used to classified the flow patterns and flow regimes in each stage and analyze the corresponding local and average heat transfer characteristics. The results indicate that a secondary enhancement in heat transfer during the transition from convective boiling (CB) to the film evaporation (FE) mechanism. The wall superheat at onset of film evaporation (ONB), onset of fully developed boiling (OFDB), and onset of film evaporation (OFE) exhibited a strong positive correlation with heat flux, while the influences of inlet temperature and mass flux were negligible. The average HTC in the narrow channel is dictated by the flow regime distribution. A comprehensive evaluation of numerous predictive models for thermal-hydraulic thresholds and heat transfer coefficients was conducted. New correlations for ONB, OFDB, OFE, and average HTC were developed and demonstrated excellent predictive accuracy, with mean relative errors (MRE) of −2.71%, −2.80%, 3.25%, and 0.19%, respectively.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"172 ","pages":"Article 110554"},"PeriodicalIF":6.4,"publicationDate":"2026-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146022693","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2026-01-22DOI: 10.1016/j.icheatmasstransfer.2026.110594
Xinxing Bian , Huining Xu , Shiyuan Li
Understanding the relationship between water saturation and capillary suction in asphalt mixtures is essential for predicting unsaturated flow and hydrological performance in pavement systems. However, rigorous experimental investigations into the saturation–capillary suction (S-Sc) curves of asphalt mixtures remain limited, and the underlying mechanisms governing their evolution are still elusive. This study aims to (1) comprehensively investigate the S-Sc curves of asphalt mixtures and their key influencing factors, and (2) clarify the pore-dependent water retention mechanism underlying the S-Sc relationship. The S-Sc curves of two common asphalt mixtures, from saturation to residual water content, were characterized through suction-controlled desaturation tests. The effects of material properties (compaction state, asphalt type, aggregate type) and environmental conditions (freeze–thaw (F–T) cycles, wet–dry (W-D) cycles) on the S-Sc curves were elucidated. Non-parametric Friedman tests and post-hoc multiple comparisons revealed that pore-related factors primarily influence the evolution of the S-Sc curves. Furthermore, correlating pore size distribution (PSD) with the S-Sc curves indicated that both the PSD and the dominant pore size control the overall shape of the curve, with a significant linear correlation observed between the inverse cumulative frequency of pore size and decrease in saturation. Nevertheless, applying classical porous media models to describe the measured S-Sc curves of asphalt mixtures showed local inadequacies and required modifications. This work provides fundamental insights for improving constitutive models of unsaturated hydraulic behavior in pavement materials and is of practical significance for evaluating moisture damage mitigation strategies and the hydrological functionality of pavements in humid and semi-humid regions.
{"title":"Saturation–capillary suction curve for unsaturated flow in asphalt mixtures: Governing factors and pore-distribution-dependent mechanism","authors":"Xinxing Bian , Huining Xu , Shiyuan Li","doi":"10.1016/j.icheatmasstransfer.2026.110594","DOIUrl":"10.1016/j.icheatmasstransfer.2026.110594","url":null,"abstract":"<div><div>Understanding the relationship between water saturation and capillary suction in asphalt mixtures is essential for predicting unsaturated flow and hydrological performance in pavement systems. However, rigorous experimental investigations into the saturation–capillary suction (<em>S</em>-<em>S</em><sub>c</sub>) curves of asphalt mixtures remain limited, and the underlying mechanisms governing their evolution are still elusive. This study aims to (1) comprehensively investigate the <em>S-S</em><sub>c</sub> curves of asphalt mixtures and their key influencing factors, and (2) clarify the pore-dependent water retention mechanism underlying the <em>S-S</em><sub>c</sub> relationship. The <em>S-S</em><sub>c</sub> curves of two common asphalt mixtures, from saturation to residual water content, were characterized through suction-controlled desaturation tests. The effects of material properties (compaction state, asphalt type, aggregate type) and environmental conditions (freeze–thaw (F–T) cycles, wet–dry (W-D) cycles) on the <em>S-S</em><sub>c</sub> curves were elucidated. Non-parametric Friedman tests and post-hoc multiple comparisons revealed that pore-related factors primarily influence the evolution of the <em>S-S</em><sub>c</sub> curves. Furthermore, correlating pore size distribution (PSD) with the <em>S-S</em><sub>c</sub> curves indicated that both the PSD and the dominant pore size control the overall shape of the curve, with a significant linear correlation observed between the inverse cumulative frequency of pore size and decrease in saturation. Nevertheless, applying classical porous media models to describe the measured <em>S-S</em><sub>c</sub> curves of asphalt mixtures showed local inadequacies and required modifications. This work provides fundamental insights for improving constitutive models of unsaturated hydraulic behavior in pavement materials and is of practical significance for evaluating moisture damage mitigation strategies and the hydrological functionality of pavements in humid and semi-humid regions.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"172 ","pages":"Article 110594"},"PeriodicalIF":6.4,"publicationDate":"2026-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146022400","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2026-01-22DOI: 10.1016/j.icheatmasstransfer.2026.110558
Majdi Amin , Mohammed El Hadi Attia , Mohamed Benghanem , Mohamed Koraiem Handawy , K. Harby , Mohamed Abdelgaied
Freshwater scarcity is one of the most significant global challenges, especially in arid and semi-arid regions. Solar still is a sustainable and low-cost option, but its application remains limited due to low productivity and efficiency. This study aims to improve the performance of a conical solar still (CSS) by integrating cylindrical magnets inside the basin to influence the behavior of water molecules and reduce surface tension and adding external reflectors to increase the absorbed solar energy. A comprehensive evaluation was conducted, including energy, exergy, economic, environmental, and eco-economic analyses, as well as sustainability indicators. Five different configurations were tested: conventional conical still (CHSS), still with reflectors (CSS&TER), still with parallel magnets and reflectors (CSS-PDM&TER), still with linear magnets and reflectors (CSS-IDM&TER), and still with zigzag magnets and reflectors (CSS-ZDM&TER). The results showed significant improvements in all developed models, with daily productivity reaching 4.24 l/m2 (CHSS), 5.58 (CSS&TER), 9.46 (CSS-PDM&TER), 7.46 (CSS-IDM&TER), and 8.52 (CSS-ZDM&TER). The thermal efficiency also increased from 32.59% (CHSS) to 43.37%, 72.97%, 56.83%, and 64.86%, while the exergy efficiency improved by 63.13%, 331.30%, 157.02%, and 234.81%, respectively. Economically, the cost of production per liter decreased from 0.0118 $/l.m2 (CHSS) to a minimum of 0.0076 $/l.m2, and the payback period was shortened from 2.36 months to 1.52 months. Environmentally, the combined lifetime net CO2 emission reductions for the distillers were 17.4 tons (CHSS), 23.1 tons (CSS&TER), 39.1 tons (CSS-PDM&TER), 30.8 tons (CSS-IDM&TER), and 35.2 tons (CSS-ZDM&TER), reflecting relative increases of 33%, 124%, 77%, and 102% compared to the conventional distiller. Carbon credit returns were 251.61 $, 334.25 $, 566.28$, 446.97$, and 510.98$, respectively, reflecting economic improvements ranging from 33% to 125%. These results confirm that integrating reflectors with magnets represents a promising approach for achieving high productivity at lower cost and with a sustainable environmental impact.
{"title":"4E assessment and production optimization of conical solar distillers: Investigating the dual effect of magnetic field distribution of disc magnets with external truncated reflectors","authors":"Majdi Amin , Mohammed El Hadi Attia , Mohamed Benghanem , Mohamed Koraiem Handawy , K. Harby , Mohamed Abdelgaied","doi":"10.1016/j.icheatmasstransfer.2026.110558","DOIUrl":"10.1016/j.icheatmasstransfer.2026.110558","url":null,"abstract":"<div><div>Freshwater scarcity is one of the most significant global challenges, especially in arid and semi-arid regions. Solar still is a sustainable and low-cost option, but its application remains limited due to low productivity and efficiency. This study aims to improve the performance of a conical solar still (CSS) by integrating cylindrical magnets inside the basin to influence the behavior of water molecules and reduce surface tension and adding external reflectors to increase the absorbed solar energy. A comprehensive evaluation was conducted, including energy, exergy, economic, environmental, and eco-economic analyses, as well as sustainability indicators. Five different configurations were tested: conventional conical still (CHSS), still with reflectors (CSS&TER), still with parallel magnets and reflectors (CSS-PDM&TER), still with linear magnets and reflectors (CSS-IDM&TER), and still with zigzag magnets and reflectors (CSS-ZDM&TER). The results showed significant improvements in all developed models, with daily productivity reaching 4.24 l/m<sup>2</sup> (CHSS), 5.58 (CSS&TER), 9.46 (CSS-PDM&TER), 7.46 (CSS-IDM&TER), and 8.52 (CSS-ZDM&TER). The thermal efficiency also increased from 32.59% (CHSS) to 43.37%, 72.97%, 56.83%, and 64.86%, while the exergy efficiency improved by 63.13%, 331.30%, 157.02%, and 234.81%, respectively. Economically, the cost of production per liter decreased from 0.0118 $/l.m<sup>2</sup> (CHSS) to a minimum of 0.0076 $/l.m<sup>2</sup>, and the payback period was shortened from 2.36 months to 1.52 months. Environmentally, the combined lifetime net CO2 emission reductions for the distillers were 17.4 tons (CHSS), 23.1 tons (CSS&TER), 39.1 tons (CSS-PDM&TER), 30.8 tons (CSS-IDM&TER), and 35.2 tons (CSS-ZDM&TER), reflecting relative increases of 33%, 124%, 77%, and 102% compared to the conventional distiller. Carbon credit returns were 251.61 $, 334.25 $, 566.28$, 446.97$, and 510.98$, respectively, reflecting economic improvements ranging from 33% to 125%. These results confirm that integrating reflectors with magnets represents a promising approach for achieving high productivity at lower cost and with a sustainable environmental impact.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"172 ","pages":"Article 110558"},"PeriodicalIF":6.4,"publicationDate":"2026-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146022399","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2026-01-22DOI: 10.1016/j.icheatmasstransfer.2026.110606
Jiling Chen , Xin Li , Jinyuan Tang , Liangliang Lv , Wen Shao , Shengyu You , Zhaoyang Tian
Accurate modeling and prediction of the lubrication state in gear transmissions are essential for high-end equipment such as aviation and new energy vehicles. Currently, research on the correlation between rough tooth surface and its lubrication characteristics is scarce. Based on extensive measured grinding topography, this paper calculated the average oil film thickness, pressure, and temperature in the Hertzian contact zone of spur gear pairs under thermoelastoplastic hydrodynamic lubrication, considering different torques and speeds. Data augmentation conforming to the correlation constraints among rough surface height characteristic parameters was developed using CTAB-GAN+ and the Johnson transformation method. The machine-learning-based surrogate model was used to relate topography parameters to the average oil film thickness. Statistical partial correlation analysis and the Sobol method were employed to identify sensitive parameters. The results show: (1) Grinding topography significantly influences the average oil film thickness, but has minor effects on the average oil film pressure and temperature; (2) Gear torque and speed alter the importance ranking of topography parameters; (3) Comprehensive evaluation shows that the most influential parameters on the average oil film thickness, in descending order, are: root mean square height (Sq), core void volume (Vvc), peak extreme height (Sxp), developed interfacial area ratio (Sdr), and core material volume (Vmc). (4) Incorporating key topography parameters beyond the widely used Sq improves prediction accuracy: The RMSE and MAE of XGBoost and RF models decreased by 19.8% ∼ 29.8% and 16.5% ∼ 18.0%, respectively. The study provides new insights and technical support for the anti-fatigue design and manufacturing of rough tooth surfaces.
{"title":"Research on the correlation between roughness parameters and lubrication characteristics of gear tooth surfaces based on thermoellastoplastic hydrodynamic lubrication","authors":"Jiling Chen , Xin Li , Jinyuan Tang , Liangliang Lv , Wen Shao , Shengyu You , Zhaoyang Tian","doi":"10.1016/j.icheatmasstransfer.2026.110606","DOIUrl":"10.1016/j.icheatmasstransfer.2026.110606","url":null,"abstract":"<div><div>Accurate modeling and prediction of the lubrication state in gear transmissions are essential for high-end equipment such as aviation and new energy vehicles. Currently, research on the correlation between rough tooth surface and its lubrication characteristics is scarce. Based on extensive measured grinding topography, this paper calculated the average oil film thickness, pressure, and temperature in the Hertzian contact zone of spur gear pairs under thermoelastoplastic hydrodynamic lubrication, considering different torques and speeds. Data augmentation conforming to the correlation constraints among rough surface height characteristic parameters was developed using CTAB-GAN+ and the Johnson transformation method. The machine-learning-based surrogate model was used to relate topography parameters to the average oil film thickness. Statistical partial correlation analysis and the Sobol method were employed to identify sensitive parameters. The results show: (1) Grinding topography significantly influences the average oil film thickness, but has minor effects on the average oil film pressure and temperature; (2) Gear torque and speed alter the importance ranking of topography parameters; (3) Comprehensive evaluation shows that the most influential parameters on the average oil film thickness, in descending order, are: root mean square height (<em>Sq</em>), core void volume (<em>Vvc</em>), peak extreme height (<em>Sxp</em>), developed interfacial area ratio (<em>Sdr</em>), and core material volume (<em>Vmc</em>). (4) Incorporating key topography parameters beyond the widely used <em>Sq</em> improves prediction accuracy: The RMSE and MAE of XGBoost and RF models decreased by 19.8% ∼ 29.8% and 16.5% ∼ 18.0%, respectively. The study provides new insights and technical support for the anti-fatigue design and manufacturing of rough tooth surfaces.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"172 ","pages":"Article 110606"},"PeriodicalIF":6.4,"publicationDate":"2026-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146022403","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2026-01-22DOI: 10.1016/j.icheatmasstransfer.2026.110520
Hussein Togun , Ali Basem , Muhsin Jaber Jweeg , Ali E. Anqi , Hayder I. Mohammed , Sivakumar Karthikeyan , Farhan Lafta Rashid , Anirban Chattopadhyay , Bhupendra K. Sharma , Ephraim Bonah Agyekum
One of the most promising technological directions towards decarbonizing transportation is Fuel Cell Electric Vehicles (FCEVs), as they have zero tailpipe emission, and are able to refuel quickly. The paper is a review of recent progress and longstanding challenges in FCEV technology. Proton exchange Membrane Fuel Cells that are commercially available reach system efficiencies of 58–62%, and have driving ranges up to 600 km, and refueling times of 3–5 min. Nevertheless, the cost of fuel cell systems has been the main obstacle to adoption, with currently high prices of systems ranging between 90 and 120$/kW, which is still considerably higher than the long-term goal of the U.S. Department of Energy of 40$/kW. Platinum-group metal catalysts and low-volume manufacturing contribute to this cost difference to a large extent. A critical assessment shows that it has a complementary relationship with Battery Electric Vehicles (BEVs): where BEVs are characterized by better well-to-wheel efficiency (≈85%), FCEVs have specific advantages in terms of required minimal downtime, long range, and high payload, such as heavy-duty transportation. The virtue of FCEVs in terms of the environment depends on hydrogen production technologies with green hydrogen through renewable-powered electrolysis being required to attain a low-carbon lifecycle. Such issues as the lack of hydrogen refueling stations, the necessity of efficient and stable catalysts at low cost, and the development of vehicle to grid systems to connect FCEVs and renewable energy grids are significant challenges. Material innovation, building infrastructure and enabling policy are important to overcome these barriers in achieving the potential of FCEVs in a sustainable mobility ecosystem.
{"title":"Fuel cell electric vehicles: Innovations, challenges, and the path to sustainable mobility","authors":"Hussein Togun , Ali Basem , Muhsin Jaber Jweeg , Ali E. Anqi , Hayder I. Mohammed , Sivakumar Karthikeyan , Farhan Lafta Rashid , Anirban Chattopadhyay , Bhupendra K. Sharma , Ephraim Bonah Agyekum","doi":"10.1016/j.icheatmasstransfer.2026.110520","DOIUrl":"10.1016/j.icheatmasstransfer.2026.110520","url":null,"abstract":"<div><div>One of the most promising technological directions towards decarbonizing transportation is Fuel Cell Electric Vehicles (FCEVs), as they have zero tailpipe emission, and are able to refuel quickly. The paper is a review of recent progress and longstanding challenges in FCEV technology. Proton exchange Membrane Fuel Cells that are commercially available reach system efficiencies of 58–62%, and have driving ranges up to 600 km, and refueling times of 3–5 min. Nevertheless, the cost of fuel cell systems has been the main obstacle to adoption, with currently high prices of systems ranging between 90 and 120$/kW, which is still considerably higher than the long-term goal of the U.S. Department of Energy of 40$/kW. Platinum-group metal catalysts and low-volume manufacturing contribute to this cost difference to a large extent. A critical assessment shows that it has a complementary relationship with Battery Electric Vehicles (BEVs): where BEVs are characterized by better well-to-wheel efficiency (≈85%), FCEVs have specific advantages in terms of required minimal downtime, long range, and high payload, such as heavy-duty transportation. The virtue of FCEVs in terms of the environment depends on hydrogen production technologies with green hydrogen through renewable-powered electrolysis being required to attain a low-carbon lifecycle. Such issues as the lack of hydrogen refueling stations, the necessity of efficient and stable catalysts at low cost, and the development of vehicle to grid systems to connect FCEVs and renewable energy grids are significant challenges. Material innovation, building infrastructure and enabling policy are important to overcome these barriers in achieving the potential of FCEVs in a sustainable mobility ecosystem.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"172 ","pages":"Article 110520"},"PeriodicalIF":6.4,"publicationDate":"2026-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146022698","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2026-01-22DOI: 10.1016/j.icheatmasstransfer.2026.110616
Burak Uguz , Andaç Batur Çolak , Yakup Karakoyun , Zafer Gemici , Ozgen Acikgoz , Ahmet Selim Dalkilic
Fan coils (FCs) are widely utilized, yet little is known about their performance under different operating conditions. A segment of a comprehensive experimental dataset with 1727 data points is used to develop and train four artificial neural network (ANN) architectures to computationally estimate the heat output and available power of a ceiling-mounted FC. The tests have been done via a specifically devised AMCA 210 test apparatus, under interior air and heat exchanger (HEX) fluid conditions recommended by EUROVENT. Utilizing six given inputs, the 1st ANN estimated the airflow rate and fan power. With five dissimilar input parameters, the exit temperature of air as well as the heating capacity was forecasted. Considering five separate inputs, the 3rd ANN assessed the pressure drops at the water side pertaining to the HEX. Depending on eight diverse inputs, the air exit temperature and power of the fan alongside total heating capacity were estimated. In the network models of 10 neurons in the hidden layer, the Levenberg-Marquardt training method has been utilized. Considering the 1st ANN, the deviation that pertained to the air flow rate was found to be −0.59%, as the deviations relevant to the air outlet temperature and heating capacity in the 2nd ANN were detected to be 0.001% and 0.03%, respectively. Additionally, the 3rd ANN resulted in a deviant value of −0.07%, referring to the fluid pressure loss. The 4th ANN has also brought about deviations of −0.005%, −0.13%, and + 0.09%, referring to exit air temperature, heating capacity, and fan power, respectively.
{"title":"Machine learning approach for multi-parameter performance estimations of EC fan coil units using heating tentative database","authors":"Burak Uguz , Andaç Batur Çolak , Yakup Karakoyun , Zafer Gemici , Ozgen Acikgoz , Ahmet Selim Dalkilic","doi":"10.1016/j.icheatmasstransfer.2026.110616","DOIUrl":"10.1016/j.icheatmasstransfer.2026.110616","url":null,"abstract":"<div><div>Fan coils (FCs) are widely utilized, yet little is known about their performance under different operating conditions. A segment of a comprehensive experimental dataset with 1727 data points is used to develop and train four artificial neural network (ANN) architectures to computationally estimate the heat output and available power of a ceiling-mounted FC. The tests have been done via a specifically devised AMCA 210 test apparatus, under interior air and heat exchanger (HEX) fluid conditions recommended by EUROVENT. Utilizing six given inputs, the 1st ANN estimated the airflow rate and fan power. With five dissimilar input parameters, the exit temperature of air as well as the heating capacity was forecasted. Considering five separate inputs, the 3rd ANN assessed the pressure drops at the water side pertaining to the HEX. Depending on eight diverse inputs, the air exit temperature and power of the fan alongside total heating capacity were estimated. In the network models of 10 neurons in the hidden layer, the Levenberg-Marquardt training method has been utilized. Considering the 1st ANN, the deviation that pertained to the air flow rate was found to be −0.59%, as the deviations relevant to the air outlet temperature and heating capacity in the 2nd ANN were detected to be 0.001% and 0.03%, respectively. Additionally, the 3rd ANN resulted in a deviant value of −0.07%, referring to the fluid pressure loss. The 4th ANN has also brought about deviations of −0.005%, −0.13%, and + 0.09%, referring to exit air temperature, heating capacity, and fan power, respectively.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"172 ","pages":"Article 110616"},"PeriodicalIF":6.4,"publicationDate":"2026-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146022692","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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