Pub Date : 2025-02-25DOI: 10.1016/j.icheatmasstransfer.2025.108786
Jianping Zhou , Shengsheng Zhang , Yinan Zhao , Zongjie Zhou , Guoyu Hu , Lizhong Wang , Yan Xu
A research method combining plasma-electrochemical corrosion multi-field coupled simulation and discharge/dissolution experiments was used to reveal the material removal mechanism of electrochemical electric arc machining (ECEAM). A jet-based plasma-electrochemical corrosion multi-field coupling model was established to describe the arc-breaking, heat-transfer, and dissolution processes under the jet electrolyte, as well as the material removal behavior of dissolution/discharge alternation. A single discharge/dissolution experiment with a constant feed rate was designed to verify the reliability of the simulation results and explain the influence mechanism and sensitivity factors of the discharge/dissolution action ratio. Continuous discharge/dissolution experiment was carried out to construct the linkage between the single discharge/dissolution of material and the material surface removal process in order to comprehensively elaborate the material removal mechanism of ECEAM.
{"title":"Research on material removal behavior and influence mechanism of electrochemical electric arc machining","authors":"Jianping Zhou , Shengsheng Zhang , Yinan Zhao , Zongjie Zhou , Guoyu Hu , Lizhong Wang , Yan Xu","doi":"10.1016/j.icheatmasstransfer.2025.108786","DOIUrl":"10.1016/j.icheatmasstransfer.2025.108786","url":null,"abstract":"<div><div>A research method combining plasma-electrochemical corrosion multi-field coupled simulation and discharge/dissolution experiments was used to reveal the material removal mechanism of electrochemical electric arc machining (ECEAM). A jet-based plasma-electrochemical corrosion multi-field coupling model was established to describe the arc-breaking, heat-transfer, and dissolution processes under the jet electrolyte, as well as the material removal behavior of dissolution/discharge alternation. A single discharge/dissolution experiment with a constant feed rate was designed to verify the reliability of the simulation results and explain the influence mechanism and sensitivity factors of the discharge/dissolution action ratio. Continuous discharge/dissolution experiment was carried out to construct the linkage between the single discharge/dissolution of material and the material surface removal process in order to comprehensively elaborate the material removal mechanism of ECEAM.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"163 ","pages":"Article 108786"},"PeriodicalIF":6.4,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143480658","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 : 2025-02-24DOI: 10.1016/j.icheatmasstransfer.2025.108760
Junjie Chen , Jiahao Qin , Xiaoxiao Wang , Fangfang Zhang , Xuehong Wu , Shang Mao , Dong Han , Weifeng He
Purposefully, a packed bed humidification experimental setup implementing multiple water injections was employed to investigate the comprehensive thermodynamically-balanced performance, with newly designed packing. The corrugated wire mesh was arranged in a dislocation arrangement in the humidifier and, the water injection bypasses were installed in a suitable packing position. Two new criteria, humidification capacity per unit volume (HCUV) and humidification capacity per unit cost (HCUC), were respectively proposed to evaluate the thermodynamic and economic performance of the humidification system. Further, the effects of the main thermodynamic parameters on the humidification performance were addressed in detail. The experimental results showed that the humidification system established was robust and available, and the evaluation criteria could effectively characterize the balance of payments between the humidification capacity and the total cost. It was found that increasing the injection times could remarkably raise the value of the HCUV, while a reverse effect acted on the HCUC for all the cases. In addition, it was illustrated that a higher inlet water temperature was beneficial to enhance the humidification performance. An elevation amplitude of the HCUV emerged as 34.57 %, 39.48 % and 35.74 % for zero, single and double water injections when the liquid-gas ratio increased from 1 to 1.36, respectively, while a peak value of 9.66 kg$−1 for the HCUC presented at mr = 1.16. Increasing the injection ratio will prominently raise the thermodynamic performance, but reduce the economic performance for double injections. Furthermore, it was demonstrated that the thermodynamic performance of the thermodynamically-balanced humidifier was improved by 38.16 % compared to the previous researches.
{"title":"Using targeted performance criteria to experimentally evaluate a packed bed humidification system with thermodynamic balancing measures","authors":"Junjie Chen , Jiahao Qin , Xiaoxiao Wang , Fangfang Zhang , Xuehong Wu , Shang Mao , Dong Han , Weifeng He","doi":"10.1016/j.icheatmasstransfer.2025.108760","DOIUrl":"10.1016/j.icheatmasstransfer.2025.108760","url":null,"abstract":"<div><div>Purposefully, a packed bed humidification experimental setup implementing multiple water injections was employed to investigate the comprehensive thermodynamically-balanced performance, with newly designed packing. The corrugated wire mesh was arranged in a dislocation arrangement in the humidifier and, the water injection bypasses were installed in a suitable packing position. Two new criteria, humidification capacity per unit volume (HCUV) and humidification capacity per unit cost (HCUC), were respectively proposed to evaluate the thermodynamic and economic performance of the humidification system. Further, the effects of the main thermodynamic parameters on the humidification performance were addressed in detail. The experimental results showed that the humidification system established was robust and available, and the evaluation criteria could effectively characterize the balance of payments between the humidification capacity and the total cost. It was found that increasing the injection times could remarkably raise the value of the HCUV, while a reverse effect acted on the HCUC for all the cases. In addition, it was illustrated that a higher inlet water temperature was beneficial to enhance the humidification performance. An elevation amplitude of the HCUV emerged as 34.57 %, 39.48 % and 35.74 % for zero, single and double water injections when the liquid-gas ratio increased from 1 to 1.36, respectively, while a peak value of 9.66 kg$<sup>−1</sup> for the HCUC presented at <em>m</em><sub><em>r</em></sub> = 1.16. Increasing the injection ratio will prominently raise the thermodynamic performance, but reduce the economic performance for double injections. Furthermore, it was demonstrated that the thermodynamic performance of the thermodynamically-balanced humidifier was improved by 38.16 % compared to the previous researches.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"163 ","pages":"Article 108760"},"PeriodicalIF":6.4,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143480129","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 : 2025-02-24DOI: 10.1016/j.icheatmasstransfer.2025.108733
Guipeng Wang , Liwen Lai , Xiangling Kong , Guangyu Wang , Zhe Li , Yuanhua Xie , Kun Liu
In a Roots dry vacuum pump, the low-pressure environment within the pump chamber hinders heat dissipation through convection. This leads to a temperature rise in the rotors and cavity, causing a reduction in internal clearances due to thermal deformation. This study employs thermocouples and infrared sensors to measure the temperatures of the cavity and rotors, respectively, thereby obtaining their temperature fields. Experiment results are used as boundary conditions for numerical analysis to further analyze the variation patterns of the internal clearances. The results show that as exhaust pressure increases, the temperatures of the cavity and rotors rise, along with the temperature difference between them, the temperature difference between the upper and lower sections of the cavity also becomes more pronounced, with the lower section exhibiting higher temperatures than the upper side. Radial clearances show greater sensitivity to temperature rises than axial clearances. Axial deformation on the end cap side is greater than that on the motor side, and the difference widens as temperature rises. When rotors mesh at the intersections of the profile curves, the inter-lobe clearance reaches its minimum. This study could offer guidance for the stable operation and clearance designing of the Roots vacuum pump.
{"title":"Thermal distribution experiment and structural deformation analysis of Roots dry vacuum pump","authors":"Guipeng Wang , Liwen Lai , Xiangling Kong , Guangyu Wang , Zhe Li , Yuanhua Xie , Kun Liu","doi":"10.1016/j.icheatmasstransfer.2025.108733","DOIUrl":"10.1016/j.icheatmasstransfer.2025.108733","url":null,"abstract":"<div><div>In a Roots dry vacuum pump, the low-pressure environment within the pump chamber hinders heat dissipation through convection. This leads to a temperature rise in the rotors and cavity, causing a reduction in internal clearances due to thermal deformation. This study employs thermocouples and infrared sensors to measure the temperatures of the cavity and rotors, respectively, thereby obtaining their temperature fields. Experiment results are used as boundary conditions for numerical analysis to further analyze the variation patterns of the internal clearances. The results show that as exhaust pressure increases, the temperatures of the cavity and rotors rise, along with the temperature difference between them, the temperature difference between the upper and lower sections of the cavity also becomes more pronounced, with the lower section exhibiting higher temperatures than the upper side. Radial clearances show greater sensitivity to temperature rises than axial clearances. Axial deformation on the end cap side is greater than that on the motor side, and the difference widens as temperature rises. When rotors mesh at the intersections of the profile curves, the inter-lobe clearance reaches its minimum. This study could offer guidance for the stable operation and clearance designing of the Roots vacuum pump.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"163 ","pages":"Article 108733"},"PeriodicalIF":6.4,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143480131","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 : 2025-02-24DOI: 10.1016/j.icheatmasstransfer.2025.108765
Junlin Chen , Wenhai Du , Keyong Cheng , Xunfeng Li , Jiangfeng Guo , Pengfei Lv , Hongsheng Dong
The hydrogen precooler is a critical component of hydrogen refueling stations (HRS), requiring high heat transfer efficiency, compactness, and pressure resistance. The printed circuit heat exchanger (PCHE) excels in high-pressure environments. However, in practical engineering applications, the refrigerant's operating pressure on the cold side is relatively low. Consequently, a hybrid PCHE incorporating a plate-fin structure on the cold side offers greater potential. This study evaluates the performance of three innovative hybrid PCHEs (semicircle-plain, semicircle-perforated, and semicircle-serrated) compared to conventional PCHEs (semicircle- semicircle) for 35 MPa and 70 MPa HRS using a segmented thermal design method coupled with a stress check. Channel geometrical parameters are optimized to minimize volume and pressure drop. Results show that hybrid PCHEs outperform conventional PCHEs, with the semicircle-serrated hybrid PCHE achieving the best performance. Its superior performance is attributed to the serrated fins, which enhance synergistic performance between local heat transfer coefficient and local heat transfer temperature difference and reduce thermal resistance, significantly lowering the required heat transfer area. At the optimal point, hybrid PCHE volume is reduced by 68.82 % (35 MPa HRS) and 33.33 % (70 MPa HRS), while pressure drops are reduced by 48.94 % and 83.73 %, respectively. This study provides valuable insights into optimizing PCHE designs for future hydrogen refueling infrastructure.
{"title":"Design analysis of a hybrid printed circuit heat exchanger for precooling in hydrogen refueling station","authors":"Junlin Chen , Wenhai Du , Keyong Cheng , Xunfeng Li , Jiangfeng Guo , Pengfei Lv , Hongsheng Dong","doi":"10.1016/j.icheatmasstransfer.2025.108765","DOIUrl":"10.1016/j.icheatmasstransfer.2025.108765","url":null,"abstract":"<div><div>The hydrogen precooler is a critical component of hydrogen refueling stations (HRS), requiring high heat transfer efficiency, compactness, and pressure resistance. The printed circuit heat exchanger (PCHE) excels in high-pressure environments. However, in practical engineering applications, the refrigerant's operating pressure on the cold side is relatively low. Consequently, a hybrid PCHE incorporating a plate-fin structure on the cold side offers greater potential. This study evaluates the performance of three innovative hybrid PCHEs (semicircle-plain, semicircle-perforated, and semicircle-serrated) compared to conventional PCHEs (semicircle- semicircle) for 35 MPa and 70 MPa HRS using a segmented thermal design method coupled with a stress check. Channel geometrical parameters are optimized to minimize volume and pressure drop. Results show that hybrid PCHEs outperform conventional PCHEs, with the semicircle-serrated hybrid PCHE achieving the best performance. Its superior performance is attributed to the serrated fins, which enhance synergistic performance between local heat transfer coefficient and local heat transfer temperature difference and reduce thermal resistance, significantly lowering the required heat transfer area. At the optimal point, hybrid PCHE volume is reduced by 68.82 % (35 MPa HRS) and 33.33 % (70 MPa HRS), while pressure drops are reduced by 48.94 % and 83.73 %, respectively. This study provides valuable insights into optimizing PCHE designs for future hydrogen refueling infrastructure.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"163 ","pages":"Article 108765"},"PeriodicalIF":6.4,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143480132","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 : 2025-02-24DOI: 10.1016/j.icheatmasstransfer.2025.108763
Mengqi Wu , Nan Gui , Xingtuan Yang , Jiyuan Tu , Shengyao Jiang
Pool boiling, a fundamental heat transfer process, has been extensively studied due to its importance in various industrial applications. This paper presents a multi-task deep learning model for simultaneous material recognition and heat flux quantification from boiling process images, providing a resource-efficient solution for engineering applications requiring precise thermal analysis. The proposed model utilizes a shared feature extraction backbone with attention-enhanced convolutional blocks and a multi-task output head to jointly handle material classification and heat flux regression tasks within a single framework. A weighted loss function is incorporated to balance the learning dynamics between tasks, enabling optimized performance for both material classification and heat flux quantification. Experimental results demonstrate the model's high accuracy in both tasks, with a material recognition accuracy of 100 % and a mean absolute error (MAE) of 0.094 W/cm2 for heat flux prediction, underscoring its reliability for practical deployment in real-time, accurate thermal monitoring and analysis. Future work will explore integrating multi-modal data, such as acoustic data, to further improve predictive performance and broaden the model's applicability in complex thermal environments.
{"title":"Multi-task image-based deep learning for boiling analysis: Material recognition and heat flux prediction","authors":"Mengqi Wu , Nan Gui , Xingtuan Yang , Jiyuan Tu , Shengyao Jiang","doi":"10.1016/j.icheatmasstransfer.2025.108763","DOIUrl":"10.1016/j.icheatmasstransfer.2025.108763","url":null,"abstract":"<div><div>Pool boiling, a fundamental heat transfer process, has been extensively studied due to its importance in various industrial applications. This paper presents a multi-task deep learning model for simultaneous material recognition and heat flux quantification from boiling process images, providing a resource-efficient solution for engineering applications requiring precise thermal analysis. The proposed model utilizes a shared feature extraction backbone with attention-enhanced convolutional blocks and a multi-task output head to jointly handle material classification and heat flux regression tasks within a single framework. A weighted loss function is incorporated to balance the learning dynamics between tasks, enabling optimized performance for both material classification and heat flux quantification. Experimental results demonstrate the model's high accuracy in both tasks, with a material recognition accuracy of 100 % and a mean absolute error (MAE) of 0.094 W/cm<sup>2</sup> for heat flux prediction, underscoring its reliability for practical deployment in real-time, accurate thermal monitoring and analysis. Future work will explore integrating multi-modal data, such as acoustic data, to further improve predictive performance and broaden the model's applicability in complex thermal environments.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"163 ","pages":"Article 108763"},"PeriodicalIF":6.4,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143474229","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 : 2025-02-24DOI: 10.1016/j.icheatmasstransfer.2025.108761
Anwen Zhao, Xiaoting Rui, Bao Rong
Pre-drying is a crucial step for removing excess solvents from nitrocellulose-based propellants. This study aims to optimize the multi-coupled mass transfer and thermal transport processes involved in the industrial-scale pre-drying of propellant grains. Dynamic modeling and statistical analyses were used to develop predictive models for the volatiles content in propellant grains and to evaluate the significance of process parameters. A multi-objective optimization algorithm was applied to determine the optimal pre-drying conditions, considering quality metrics and the range of process parameters used in actual production. Air temperature was the primary factor influencing changes in the liquid ethanol and moisture contents within propellant grains, whereas processing time predominantly affected the variation in liquid ether content. Higher air temperature and mass flow rate enhanced solvent removal during the initial stage of pre-drying. Raising air temperature increased the moisture adsorption rate during the early stages of pre-drying and improved the moisture adsorption capacity of the propellant grains. The optimal conditions were identified as an air temperature of 316.4 K, relative humidity of 86.5 %, mass flow rate of 361.7 kg·h−1, and processing time of 113.6 min. The predictive models for volatiles content in propellant grains exhibit high accuracy and can effectively guide industrial production processes.
{"title":"Modeling and optimization for solvent removal coupled with moisture adsorption in pre-drying of propellant grains","authors":"Anwen Zhao, Xiaoting Rui, Bao Rong","doi":"10.1016/j.icheatmasstransfer.2025.108761","DOIUrl":"10.1016/j.icheatmasstransfer.2025.108761","url":null,"abstract":"<div><div>Pre-drying is a crucial step for removing excess solvents from nitrocellulose-based propellants. This study aims to optimize the multi-coupled mass transfer and thermal transport processes involved in the industrial-scale pre-drying of propellant grains. Dynamic modeling and statistical analyses were used to develop predictive models for the volatiles content in propellant grains and to evaluate the significance of process parameters. A multi-objective optimization algorithm was applied to determine the optimal pre-drying conditions, considering quality metrics and the range of process parameters used in actual production. Air temperature was the primary factor influencing changes in the liquid ethanol and moisture contents within propellant grains, whereas processing time predominantly affected the variation in liquid ether content. Higher air temperature and mass flow rate enhanced solvent removal during the initial stage of pre-drying. Raising air temperature increased the moisture adsorption rate during the early stages of pre-drying and improved the moisture adsorption capacity of the propellant grains. The optimal conditions were identified as an air temperature of 316.4 K, relative humidity of 86.5 %, mass flow rate of 361.7 kg·h<sup>−1</sup>, and processing time of 113.6 min. The predictive models for volatiles content in propellant grains exhibit high accuracy and can effectively guide industrial production processes.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"163 ","pages":"Article 108761"},"PeriodicalIF":6.4,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143474230","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 : 2025-02-24DOI: 10.1016/j.icheatmasstransfer.2025.108776
Xinyu Huang , Zhao Du , Junfei Guo , Yuan Xie , Xiaohu Yang , Bengt Sundén
The low thermal conductivity inherent to phase change materials (PCMs) presents challenges for implementing phase change energy storage (PCES) technologies. In this study, the enhanced heat transfer properties of 9 fins, copper metal foam with 0.98 porosity-10 PPI, and fin-metal foam composite structures are compared with pure PCM structures in square PCES units. The charging and discharging process of four structures in a complete heat storage and release cycle is studied by numerical simulation. Firstly, feasibility analysis and experimental verification are carried out to verify the accuracy of the numerical model. Then, the liquid phase behavior, temperature gradient and energy storage/release performance of the four PCES structures are compared. The results show that the fin-metal foam composite structure can further improve the phase transition rate compared with a single enhanced heat transfer measure. During melting and solidification, the storage period and release period of PCM structure are shortened by 83.91 % and 96.38 % respectively. At the end of the charging and discharging process, the average heat storage and heat release rate of the composite structure are 466.40 % and 24.91 times higher than that of the pure PCM structure, respectively. However, due to the use of fin-metal foam, the amount of heat absorption and release in the phase change material is reduced by 9.08 % and 5.89 %.
{"title":"Numerical study on melting-solidification cycle of phase change energy storage unit: Role of fin and metal foam hybrid structure","authors":"Xinyu Huang , Zhao Du , Junfei Guo , Yuan Xie , Xiaohu Yang , Bengt Sundén","doi":"10.1016/j.icheatmasstransfer.2025.108776","DOIUrl":"10.1016/j.icheatmasstransfer.2025.108776","url":null,"abstract":"<div><div>The low thermal conductivity inherent to phase change materials (PCMs) presents challenges for implementing phase change energy storage (PCES) technologies. In this study, the enhanced heat transfer properties of 9 fins, copper metal foam with 0.98 porosity-10 PPI, and fin-metal foam composite structures are compared with pure PCM structures in square PCES units. The charging and discharging process of four structures in a complete heat storage and release cycle is studied by numerical simulation. Firstly, feasibility analysis and experimental verification are carried out to verify the accuracy of the numerical model. Then, the liquid phase behavior, temperature gradient and energy storage/release performance of the four PCES structures are compared. The results show that the fin-metal foam composite structure can further improve the phase transition rate compared with a single enhanced heat transfer measure. During melting and solidification, the storage period and release period of PCM structure are shortened by 83.91 % and 96.38 % respectively. At the end of the charging and discharging process, the average heat storage and heat release rate of the composite structure are 466.40 % and 24.91 times higher than that of the pure PCM structure, respectively. However, due to the use of fin-metal foam, the amount of heat absorption and release in the phase change material is reduced by 9.08 % and 5.89 %.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"163 ","pages":"Article 108776"},"PeriodicalIF":6.4,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143480134","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}
No doubt that the recovery of the wasted heat and the maximizing of heat transmission rates are of great interest to engineers and scientists due to their direct impact on global warming. In this article, The thermal efficiency of a Latent Heat Storage (LHS) system was numerically studied with the aim of augmenting its performance. The Double-diffusive convection of Nano-encapsulated phase change material (NEPCM), confined in an annulus between an inner Koch snowflake cylinder and an outer hexagon, is considered and analyzed. A key contribution of this study is the application of a stabilized Galerkin finite element method)GFEM(for numerical modeling. The study spans a broad range of parameters, including Rayleigh numbers (Ra = 103 to 106), Darcy parameters (Da = 10−2 to 10−5), Lewis numbers (Le = 0.1 to 5), and the inner cylinder shape (triangle, Koch snowflake). The results are presented in the form of streamlines, isotherms and heat capacity ratio (Cr). The findings suggested that increasing Ra and Da significantly augmented the heat transfer rates, while the impact of Le was less important. At the highest studied Ra, increasing Da to 10−5 and improved heat transmission rate by 160 %, whereas it decreased by 22 % when Le increased to 5. Moreover, it was noted that the triangular body has a better heat transmission rate in comparison with the other two bodies. The triangular shape resulted in a 116 % increment in the heat transmission rate compared to the snowflake shape.
{"title":"Double diffusion heat convection of a porous enclosure loaded with nano-encapsulated phase change materials","authors":"Abed Mourad , Naim Hocine , Aissa Abderrahmane , Obai Younis , Riadh Marzouki","doi":"10.1016/j.icheatmasstransfer.2025.108764","DOIUrl":"10.1016/j.icheatmasstransfer.2025.108764","url":null,"abstract":"<div><div>No doubt that the recovery of the wasted heat and the maximizing of heat transmission rates are of great interest to engineers and scientists due to their direct impact on global warming. In this article, The thermal efficiency of a Latent Heat Storage (LHS) system was numerically studied with the aim of augmenting its performance. The Double-diffusive convection of Nano-encapsulated phase change material (NEPCM), confined in an annulus between an inner Koch snowflake cylinder and an outer hexagon, is considered and analyzed. A key contribution of this study is the application of a stabilized Galerkin finite element method)GFEM(for numerical modeling. The study spans a broad range of parameters, including Rayleigh numbers (<em>Ra</em> = 10<sup>3</sup> to 10<sup>6</sup>), Darcy parameters (<em>Da</em> = 10<sup>−2</sup> to 10<sup>−5</sup>), Lewis numbers (<em>Le</em> = 0.1 to 5), and the inner cylinder shape (triangle, Koch snowflake). The results are presented in the form of streamlines, isotherms and heat capacity ratio (Cr). The findings suggested that increasing <em>Ra</em> and <em>Da</em> significantly augmented the heat transfer rates, while the impact of <em>Le</em> was less important. At the highest studied Ra, increasing Da to 10<sup>−5</sup> and improved heat transmission rate by 160 %, whereas it decreased by 22 % when Le increased to 5. Moreover, it was noted that the triangular body has a better heat transmission rate in comparison with the other two bodies. The triangular shape resulted in a 116 % increment in the heat transmission rate compared to the snowflake shape.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"163 ","pages":"Article 108764"},"PeriodicalIF":6.4,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143480133","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 : 2025-02-24DOI: 10.1016/j.icheatmasstransfer.2025.108738
Han Wang , Qinjun Kang , Wendong Wang , Wu He , Yuxuan Xia , Jianchao Cai
The complex phase behaviors of oil-CO2 immiscible diffusion and oil swelling in shale nanoscale space under the influence of competitive adsorption caused by fluid-solid interaction force are still unclear, which is significantly important for shale oil recovery and carbon sequestration. In this paper, a multi-relaxation-time lattice Boltzmann method integrating the two-phase two-component three-distribution Shan-Chen flow model and mass transfer model is established to simulate the CO2 diffusion through immiscible phase interfaces, oil-dissolved CO2 competitive adsorption on the mineral surfaces, and oil swelling in nanoporous media. The proposed model is verified by the microfluidic experiment to successfully capture the diffusion and swelling. Then, the effects of equilibrium dissolution concentration and competitive adsorption on CO2 diffusion/dissolution and oil swelling are studied. The results show that as the equilibrium dissolution concentration increases, the dissolution rate of CO2 is accelerated, resulting in the increase of oil swelling volume and the dissolved CO2 adsorption concentration. The mass of CO2 diffusing into the oil phase increases with CO2 adsorption capacity, but the oil swelling volume decreases because of the increased CO2 adsorption on mineral surfaces.
{"title":"Oil-CO2 phase behavior in nanoporous media: A lattice Boltzmann study","authors":"Han Wang , Qinjun Kang , Wendong Wang , Wu He , Yuxuan Xia , Jianchao Cai","doi":"10.1016/j.icheatmasstransfer.2025.108738","DOIUrl":"10.1016/j.icheatmasstransfer.2025.108738","url":null,"abstract":"<div><div>The complex phase behaviors of oil-CO<sub>2</sub> immiscible diffusion and oil swelling in shale nanoscale space under the influence of competitive adsorption caused by fluid-solid interaction force are still unclear, which is significantly important for shale oil recovery and carbon sequestration. In this paper, a multi-relaxation-time lattice Boltzmann method integrating the two-phase two-component three-distribution Shan-Chen flow model and mass transfer model is established to simulate the CO<sub>2</sub> diffusion through immiscible phase interfaces, oil-dissolved CO<sub>2</sub> competitive adsorption on the mineral surfaces, and oil swelling in nanoporous media. The proposed model is verified by the microfluidic experiment to successfully capture the diffusion and swelling. Then, the effects of equilibrium dissolution concentration and competitive adsorption on CO<sub>2</sub> diffusion/dissolution and oil swelling are studied. The results show that as the equilibrium dissolution concentration increases, the dissolution rate of CO<sub>2</sub> is accelerated, resulting in the increase of oil swelling volume and the dissolved CO<sub>2</sub> adsorption concentration. The mass of CO<sub>2</sub> diffusing into the oil phase increases with CO<sub>2</sub> adsorption capacity, but the oil swelling volume decreases because of the increased CO<sub>2</sub> adsorption on mineral surfaces.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"163 ","pages":"Article 108738"},"PeriodicalIF":6.4,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143480130","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 : 2025-02-22DOI: 10.1016/j.icheatmasstransfer.2025.108729
Jinggang Zhang , Wei Zhao , Haihu Liu , Dong Wang , Haihang Cui , Li Chen
The dynamic behaviour of droplets impacting on both flat and cone-arrayed microstructural surfaces is investigated using an improved colour-gradient lattice Boltzmann method. We first study the effect of the Reynolds number () on the dynamic behaviour of the impacting droplet by fixing the Weber number () at 10. As increases, the maximum dimensionless mass centroid of the droplet () for the droplet impact on a cone-arrayed surface is first larger and then smaller than that on a flat surface, indicating that the cone-arrayed surface changes from promoting to preventing the rebound of the droplet from the solid surface. Next, the effect of on the dynamic behaviour of the impacting droplet is studied by fixing . For the droplet impact on a flat surface, first increases and then decreases with increasing , and its maximum value is reached near . For the droplet impact on a cone-arrayed surface, monotonically decreases with increasing . Finally, the study concludes with phase diagrams that illustrate how the droplet rebound patterns and maximum rebound height vary with and , providing valuable insights for optimizing textured surface designs in applications requiring precise droplet control.
{"title":"Numerical study of droplets impacting on flat and cone-arrayed surfaces","authors":"Jinggang Zhang , Wei Zhao , Haihu Liu , Dong Wang , Haihang Cui , Li Chen","doi":"10.1016/j.icheatmasstransfer.2025.108729","DOIUrl":"10.1016/j.icheatmasstransfer.2025.108729","url":null,"abstract":"<div><div>The dynamic behaviour of droplets impacting on both flat and cone-arrayed microstructural surfaces is investigated using an improved colour-gradient lattice Boltzmann method. We first study the effect of the Reynolds number (<span><math><mo>Re</mo></math></span>) on the dynamic behaviour of the impacting droplet by fixing the Weber number (<span><math><mi>We</mi></math></span>) at 10. As <span><math><mo>Re</mo></math></span> increases, the maximum dimensionless mass centroid of the droplet (<span><math><msup><msub><mi>z</mi><mi>cmax</mi></msub><mo>∗</mo></msup></math></span>) for the droplet impact on a cone-arrayed surface is first larger and then smaller than that on a flat surface, indicating that the cone-arrayed surface changes from promoting to preventing the rebound of the droplet from the solid surface. Next, the effect of <span><math><mi>We</mi></math></span> on the dynamic behaviour of the impacting droplet is studied by fixing <span><math><mo>Re</mo><mo>=</mo><mn>350</mn></math></span>. For the droplet impact on a flat surface, <span><math><msup><msub><mi>z</mi><mi>cmax</mi></msub><mo>∗</mo></msup></math></span> first increases and then decreases with increasing <span><math><mi>We</mi></math></span>, and its maximum value is reached near <span><math><mi>We</mi><mo>=</mo><mn>20</mn></math></span>. For the droplet impact on a cone-arrayed surface, <span><math><msup><msub><mi>z</mi><mi>cmax</mi></msub><mo>∗</mo></msup></math></span> monotonically decreases with increasing <span><math><mi>We</mi></math></span>. Finally, the study concludes with phase diagrams that illustrate how the droplet rebound patterns and maximum rebound height vary with <span><math><mo>Re</mo></math></span> and <span><math><mi>We</mi></math></span>, providing valuable insights for optimizing textured surface designs in applications requiring precise droplet control.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"163 ","pages":"Article 108729"},"PeriodicalIF":6.4,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143465455","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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