The continuous drive to improve the efficiency and power output of gas turbines has led to the need for advanced cooling strategies that can effectively dissipate high thermal loads. This study presents a comparative analysis of the thermal performance of various micro-hole configurations integrated with a main cooling hole, highlighting their synergistic effects on film-cooling effectiveness and flow behavior. Five distinct configurations were evaluated at three different blowing ratios of 0.25, 0.5, and 1.0. The SST k-ω turbulence model is employed to simulate the turbulent flow. Outcomes reveal that regardless of the configuration of micro-holes, their combination with the main hole of film cooling could increase the cooling effectiveness. Also, the comparison of different configurations demonstrates that the Quad-type (QT) configuration consistently outperformed the other designs at all tested blowing ratios. At a blowing ratio of 0.5, the QT configuration exhibited the highest centerline cooling effectiveness, with a value of 0.44 compared to 0.37 for the Step-type (ST) configuration at the X/D = 30 location. Additionally, the QT configuration had the highest spanwise-averaged cooling effectiveness, with a value of 0.3170 at X/R = 20, representing a 54.9 % improvement over the previously proposed design. Furthermore, the QT configuration demonstrated the best cooling uniformity, as indicated by the lowest CUC among the investigated configurations.
{"title":"Synergistic effects of micro-hole injection and film cooling for increasing the cooling effectiveness: A numerical investigation","authors":"Milad Mahdian Dowlatabadi , Saeed Rostami , Sepehr Sheikhlari , Khodayar Javadi","doi":"10.1016/j.ijft.2025.101497","DOIUrl":"10.1016/j.ijft.2025.101497","url":null,"abstract":"<div><div>The continuous drive to improve the efficiency and power output of gas turbines has led to the need for advanced cooling strategies that can effectively dissipate high thermal loads. This study presents a comparative analysis of the thermal performance of various micro-hole configurations integrated with a main cooling hole, highlighting their synergistic effects on film-cooling effectiveness and flow behavior. Five distinct configurations were evaluated at three different blowing ratios of 0.25, 0.5, and 1.0. The SST k-ω turbulence model is employed to simulate the turbulent flow. Outcomes reveal that regardless of the configuration of micro-holes, their combination with the main hole of film cooling could increase the cooling effectiveness. Also, the comparison of different configurations demonstrates that the Quad-type (QT) configuration consistently outperformed the other designs at all tested blowing ratios. At a blowing ratio of 0.5, the QT configuration exhibited the highest centerline cooling effectiveness, with a value of 0.44 compared to 0.37 for the Step-type (ST) configuration at the X/<em>D</em> = 30 location. Additionally, the QT configuration had the highest spanwise-averaged cooling effectiveness, with a value of 0.3170 at X/<em>R</em> = 20, representing a 54.9 % improvement over the previously proposed design. Furthermore, the QT configuration demonstrated the best cooling uniformity, as indicated by the lowest CUC among the investigated configurations.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"30 ","pages":"Article 101497"},"PeriodicalIF":0.0,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145614335","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sustainable freshwater plays a key role in human life and the rapid growth of industry. However, freshwater sources are limited even when seawater constitutes most of the available water on the earth. Converting seawater into freshwater via desalination, particularly using low-grade heat, presents a promising solution for sustainable freshwater need. This paper proposes a theoretical and experimental investigation of a thermally driven vacuum desalination system (TDVDS). The primary objective is to demonstrate the system’s ability to produce freshwater when driven by an ultra-low temperature heat source (50 – 70 °C), while the heat sink is maintained at 30 °C. A mathematical model is developed to predict freshwater production and assess the TDVDS’s working characteristics. An experimental test rig is constructed to provide validation data. The simulated results are validated against experimental data under identical working conditions to demonstrate the model’s accuracy. The TDVDS is found to operate stably and provide acceptable performance, producing freshwater with a thermal efficiency of 54 – 67 %. An discrepancy of around 5 – 10 % is observed between simulated and experimental results. Freshwater production increases linearly with distillation time, indicating a constant evaporation rate under steady-state operation. An increase in heat source temperature yields a higher freshwater production and improved thermal efficiency. The mathematical model proved to be an efficient tool for assessing the system’s working characteristics. The contributions of this work serve as a reference case for further development and practical application of the TDVDS, for which sustainable freshwater is a major achievement.
{"title":"Experimental and theoretical investigation of vacuum-based seawater desalination system driven by ultra-low temperature heat source","authors":"Tongchana Thongtip, Wichean Singmai, Pichet Janpla, Teerapharp Amornsawaddirak, Kittiwoot Sutthivirode","doi":"10.1016/j.ijft.2025.101502","DOIUrl":"10.1016/j.ijft.2025.101502","url":null,"abstract":"<div><div>Sustainable freshwater plays a key role in human life and the rapid growth of industry. However, freshwater sources are limited even when seawater constitutes most of the available water on the earth. Converting seawater into freshwater via desalination, particularly using low-grade heat, presents a promising solution for sustainable freshwater need. This paper proposes a theoretical and experimental investigation of a thermally driven vacuum desalination system (TDVDS). The primary objective is to demonstrate the system’s ability to produce freshwater when driven by an ultra-low temperature heat source (50 – 70 °C), while the heat sink is maintained at 30 °C. A mathematical model is developed to predict freshwater production and assess the TDVDS’s working characteristics. An experimental test rig is constructed to provide validation data. The simulated results are validated against experimental data under identical working conditions to demonstrate the model’s accuracy. The TDVDS is found to operate stably and provide acceptable performance, producing freshwater with a thermal efficiency of 54 – 67 %. An discrepancy of around 5 – 10 % is observed between simulated and experimental results. Freshwater production increases linearly with distillation time, indicating a constant evaporation rate under steady-state operation. An increase in heat source temperature yields a higher freshwater production and improved thermal efficiency. The mathematical model proved to be an efficient tool for assessing the system’s working characteristics. The contributions of this work serve as a reference case for further development and practical application of the TDVDS, for which sustainable freshwater is a major achievement.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"30 ","pages":"Article 101502"},"PeriodicalIF":0.0,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145568804","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01DOI: 10.1016/j.ijft.2025.101472
Jun Ma , Xiaobo Cao , Xin Yang , Peng Ren , Dan Shao , Yusen Zhang
To more accurately describe the load evolution law and its relationship with other variables, obtain the phase-space representation of the load data, and achieve accurate prediction of the short-term load of the DIES, a short-term load prediction method for the DIES based on multivariate phase-space reconstruction is proposed. Through correlation analysis of the short-term loads of DIES, the relationship between electric, cooling, and heating loads and meteorological characteristics is evaluated using the Pearson correlation coefficient to determine the input multivariate variables of the prediction model. The multivariate phase-space reconstruction technique is employed, and the delay time and embedding dimensions of the time series of the multivariate variables are determined by using the CC algorithm to optimize the phase-space reconstruction process, obtaining the phase-space representation of the electric, cooling, and heating loads and meteorological characteristics. The coupling characteristics of the electricity, cooling and heating loads and the meteorological characteristics over time are explored. Based on the Kalman filtering algorithm, a short-term load forecasting model for DIES is established, and the phase points reconstructed in phase space are used as the state vectors, which constitute the state-space description of the phase points. Kalman filtering theory is applied to realize the accurate forecasting of future short-term loads. The experimental results demonstrate that the method can clarify the correlation between electricity, cooling, and heating loads, and meteorological data through Pearson correlation analysis, and accordingly select an 8-dimensional multivariate time series for short-term load prediction. This method can accurately predict short-term changes in electricity, cooling, and heating loads with high prediction accuracy and stability. The root mean square error is 0.52 MW, the mean absolute error is 0.38 MW, the mean absolute percentage error is 2.1 %, and the p-values are all <0.01.
{"title":"A short-term load forecasting method for integrated regional energy systems based on multivariate phase space reconstruction","authors":"Jun Ma , Xiaobo Cao , Xin Yang , Peng Ren , Dan Shao , Yusen Zhang","doi":"10.1016/j.ijft.2025.101472","DOIUrl":"10.1016/j.ijft.2025.101472","url":null,"abstract":"<div><div>To more accurately describe the load evolution law and its relationship with other variables, obtain the phase-space representation of the load data, and achieve accurate prediction of the short-term load of the DIES, a short-term load prediction method for the DIES based on multivariate phase-space reconstruction is proposed. Through correlation analysis of the short-term loads of DIES, the relationship between electric, cooling, and heating loads and meteorological characteristics is evaluated using the Pearson correlation coefficient to determine the input multivariate variables of the prediction model. The multivariate phase-space reconstruction technique is employed, and the delay time and embedding dimensions of the time series of the multivariate variables are determined by using the C<img>C algorithm to optimize the phase-space reconstruction process, obtaining the phase-space representation of the electric, cooling, and heating loads and meteorological characteristics. The coupling characteristics of the electricity, cooling and heating loads and the meteorological characteristics over time are explored. Based on the Kalman filtering algorithm, a short-term load forecasting model for DIES is established, and the phase points reconstructed in phase space are used as the state vectors, which constitute the state-space description of the phase points. Kalman filtering theory is applied to realize the accurate forecasting of future short-term loads. The experimental results demonstrate that the method can clarify the correlation between electricity, cooling, and heating loads, and meteorological data through Pearson correlation analysis, and accordingly select an 8-dimensional multivariate time series for short-term load prediction. This method can accurately predict short-term changes in electricity, cooling, and heating loads with high prediction accuracy and stability. The root mean square error is 0.52 MW, the mean absolute error is 0.38 MW, the mean absolute percentage error is 2.1 %, and the p-values are all <0.01.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"30 ","pages":"Article 101472"},"PeriodicalIF":0.0,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145520093","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01DOI: 10.1016/j.ijft.2025.101501
Abdellah Idrissi , Elbachir Abddaim , Hicham El Mghari , Rachid El Amraoui , Siham Sakami , Lahcen Boukhattem
This study numerically investigates the effect of plate configurations on thermal stratification performance and energy efficiency of solar hot water storage tanks, emphasizing the role of plate configurations in enhancing energy efficiency. Using a detailed three-dimensional model comprising fluid flow and heat transfer equations, accompanied by Boussinesq approximation, the study analyzes the impact of plate size, placement, and inlet design on temperature distribution and thermocline behavior. Key performance indicators including the Richardson number (Ri), stratification number (St), pressure drop (ΔP), and discharging efficiency were assessed. Validation against experimental data confirmed the model's reliability, with discrepancies remaining below 5 %. The obtained results showed that the perforated plates with 25 % open area achieved the highest Ri (55.36), the lowest ΔP (6.68 Pa), and pumping energy (0.178 μW), along with the most efficient stratification performance. In contrast, solid plates provided balanced stratification with Ri values of 4.79 and moderate ΔP of about 7.84 Pa. The outcomes confirm that plate diameter, placement near the thermocline, and perforation design significantly impact thermal stratification and energy efficiency, offering critical insights for optimizing thermal energy storage in renewable energy systems.
{"title":"Effect of plate configurations on thermal stratification and energy efficiency in solar hot water storage tanks: A CFD-based analysis","authors":"Abdellah Idrissi , Elbachir Abddaim , Hicham El Mghari , Rachid El Amraoui , Siham Sakami , Lahcen Boukhattem","doi":"10.1016/j.ijft.2025.101501","DOIUrl":"10.1016/j.ijft.2025.101501","url":null,"abstract":"<div><div>This study numerically investigates the effect of plate configurations on thermal stratification performance and energy efficiency of solar hot water storage tanks, emphasizing the role of plate configurations in enhancing energy efficiency. Using a detailed three-dimensional model comprising fluid flow and heat transfer equations, accompanied by Boussinesq approximation, the study analyzes the impact of plate size, placement, and inlet design on temperature distribution and thermocline behavior. Key performance indicators including the Richardson number (Ri), stratification number (St), pressure drop (ΔP), and discharging efficiency were assessed. Validation against experimental data confirmed the model's reliability, with discrepancies remaining below 5 %. The obtained results showed that the perforated plates with 25 % open area achieved the highest Ri (55.36), the lowest ΔP (6.68 Pa), and pumping energy (0.178 μW), along with the most efficient stratification performance. In contrast, solid plates provided balanced stratification with Ri values of 4.79 and moderate ΔP of about 7.84 Pa. The outcomes confirm that plate diameter, placement near the thermocline, and perforation design significantly impact thermal stratification and energy efficiency, offering critical insights for optimizing thermal energy storage in renewable energy systems.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"30 ","pages":"Article 101501"},"PeriodicalIF":0.0,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145614334","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01DOI: 10.1016/j.ijft.2025.101505
Ammar Alkhalidi , Abdulnaser Bdiwi , Mohamad K. Khawaja
Wind speeds, high or low, have a detrimental effect on the rated turbine’s rotational speed in wind energy systems. This study proposes an electromagnetic torque modulation enhancement system that consists of a brushless motor mounted on the turbine’s shaft to enhance the rotational speed by generating a magnetic field. This enhancement raises and lowers the rotational speed of the wind turbine blades as needed. For testing, a horizontal wind turbine consisting of a micro-generator connected to 820 mm rotor diameter was used, with a rated power of 8 W, and it was installed at 700 mm above ground. The enhancement system was evaluated under four different scenarios. Results showed that when the enhancement system decreased the rotational speed, it was able to recover a large portion of the energy that would have been curtailed in the case of cut-out speed and lost only 5.7% of the energy compared to 100% if the wind turbine was shut down due to overspeed. However, when the enhancement system increased the rotational speed or maintained it at a range of 500–750 RPM, it improved by 1%.
{"title":"Experimental investigation of an enhancement system to improve wind turbines power generation","authors":"Ammar Alkhalidi , Abdulnaser Bdiwi , Mohamad K. Khawaja","doi":"10.1016/j.ijft.2025.101505","DOIUrl":"10.1016/j.ijft.2025.101505","url":null,"abstract":"<div><div>Wind speeds, high or low, have a detrimental effect on the rated turbine’s rotational speed in wind energy systems. This study proposes an electromagnetic torque modulation enhancement system that consists of a brushless motor mounted on the turbine’s shaft to enhance the rotational speed by generating a magnetic field. This enhancement raises and lowers the rotational speed of the wind turbine blades as needed. For testing, a horizontal wind turbine consisting of a micro-generator connected to 820 mm rotor diameter was used, with a rated power of 8 W, and it was installed at 700 mm above ground. The enhancement system was evaluated under four different scenarios. Results showed that when the enhancement system decreased the rotational speed, it was able to recover a large portion of the energy that would have been curtailed in the case of cut-out speed and lost only 5.7% of the energy compared to 100% if the wind turbine was shut down due to overspeed. However, when the enhancement system increased the rotational speed or maintained it at a range of 500–750 RPM, it improved by 1%.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"30 ","pages":"Article 101505"},"PeriodicalIF":0.0,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145614332","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01DOI: 10.1016/j.ijft.2025.101504
Reza Kaviani, Iman Ghamarian, Hamidreza Shabgard, Pejman Kazempoor
Close-contact melting is a multiphase multiscale phenomenon that occurs during unconstrained melting of phase change materials (PCM) in a heated capsule and is characterized by the formation of a liquid film between the sinking/rising solid PCM and the heated wall. This research investigates the utilization of the artificial neural network (ANN) to predict the melting rate of PCM with and without nano-additives during the close-contact melting process within a spherical capsule. The main parameters controlling the close-contact melting process, namely the capsule size, the heated wall temperature, and the thermophysical properties of the PCM, are accounted for in the ANN model through the introduction of six dimensionless groups: Fourier (Fo), Stefan (Ste), Grashof (Gr), Galileo (Ga), Archimedes (Ar), and Prandtl (Pr). To train the neural network, a comprehensive dataset comprising over 1000 data points from 50 different experimental studies reported in the literature was employed. The ANN model proved successful in predicting the quantitative and qualitative influence of the control parameters. Most notably, it was found that the PCM melting rate accelerates by increasing Ste, Gr, Ga, and Ar numbers, and by decreasing Pr number, however, the extent of their respective impacts varies significantly. This work demonstrates the usefulness of ANN for the analysis of problems that are challenging to simulate using traditional computational methods due to the presence of fluid-solid interactions and multiphase multiscale features such as melting and thin liquid film formation.
{"title":"Artificial neural network prediction of unconstrained close-contact melting of phase change materials within spherical capsules","authors":"Reza Kaviani, Iman Ghamarian, Hamidreza Shabgard, Pejman Kazempoor","doi":"10.1016/j.ijft.2025.101504","DOIUrl":"10.1016/j.ijft.2025.101504","url":null,"abstract":"<div><div>Close-contact melting is a multiphase multiscale phenomenon that occurs during unconstrained melting of phase change materials (PCM) in a heated capsule and is characterized by the formation of a liquid film between the sinking/rising solid PCM and the heated wall. This research investigates the utilization of the artificial neural network (ANN) to predict the melting rate of PCM with and without nano-additives during the close-contact melting process within a spherical capsule. The main parameters controlling the close-contact melting process, namely the capsule size, the heated wall temperature, and the thermophysical properties of the PCM, are accounted for in the ANN model through the introduction of six dimensionless groups: Fourier (Fo), Stefan (Ste), Grashof (Gr), Galileo (Ga), Archimedes (Ar), and Prandtl (Pr). To train the neural network, a comprehensive dataset comprising over 1000 data points from 50 different experimental studies reported in the literature was employed. The ANN model proved successful in predicting the quantitative and qualitative influence of the control parameters. Most notably, it was found that the PCM melting rate accelerates by increasing Ste, Gr, Ga, and Ar numbers, and by decreasing Pr number, however, the extent of their respective impacts varies significantly. This work demonstrates the usefulness of ANN for the analysis of problems that are challenging to simulate using traditional computational methods due to the presence of fluid-solid interactions and multiphase multiscale features such as melting and thin liquid film formation.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"30 ","pages":"Article 101504"},"PeriodicalIF":0.0,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145681093","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01DOI: 10.1016/j.ijft.2025.101512
Muhammad Ahmad, Mohammad O. Hamdan, Bassam A. Abu-Nabah
The current study numerically investigates the thermal performance and optimization of metal foam (MF) heat sinks for electronic cooling applications. Key design parameters include different types of phase change material (PCM) (RT31, RT42, RT55), MF porosity (0.1–95 %), MF material (aluminum, copper, stainless steel), MF permeability (10–8–10–12), and heat flux levels (1000–8000 W/m2). The simulations, conducted using ANSYS Fluent, optimize a plate-fin heat sink based on a critical temperature of 80 °C while incorporating the Boussinesq approximation for buoyancy effects. Results suggest that high-porosity metal foam enhances heat dissipation by increasing the effective thermal conductivity of the PCM-metal foam system, which accelerates PCM melting and solidification, reduces base-surface temperature, and improves overall thermal management. RT55’s higher melting point extends solid-state heat absorption by 23.5 min versus RT31 and 16.3 min versus RT42 for aluminum foam with 95 % porosity at 2000 W/m2. The effects of permeability and gravity are negligible in the presence of metal foam. The optimal configuration is RT55 infused with 95 % porous copper foam, maximizing thermal energy storage. Additionally, higher porosity increases melting time due to the larger PCM volume, while PCM selection significantly impacts thermal efficiency. Heat sink size also influences foam material effectiveness, affecting heat transfer and fluid flow dynamics.
{"title":"Enhanced electronic cooling with optimized metal foam/PCM composite heat sinks: A numerical study","authors":"Muhammad Ahmad, Mohammad O. Hamdan, Bassam A. Abu-Nabah","doi":"10.1016/j.ijft.2025.101512","DOIUrl":"10.1016/j.ijft.2025.101512","url":null,"abstract":"<div><div>The current study numerically investigates the thermal performance and optimization of metal foam (MF) heat sinks for electronic cooling applications. Key design parameters include different types of phase change material (PCM) (RT31, RT42, RT55), MF porosity (0.1–95 %), MF material (aluminum, copper, stainless steel), MF permeability (10<sup>–8</sup>–10<sup>–12</sup>), and heat flux levels (1000–8000 W/m<sup>2</sup>). The simulations, conducted using ANSYS Fluent, optimize a plate-fin heat sink based on a critical temperature of 80 °C while incorporating the Boussinesq approximation for buoyancy effects. Results suggest that high-porosity metal foam enhances heat dissipation by increasing the effective thermal conductivity of the PCM-metal foam system, which accelerates PCM melting and solidification, reduces base-surface temperature, and improves overall thermal management. RT55’s higher melting point extends solid-state heat absorption by 23.5 min versus RT31 and 16.3 min versus RT42 for aluminum foam with 95 % porosity at 2000 W/m<sup>2</sup>. The effects of permeability and gravity are negligible in the presence of metal foam. The optimal configuration is RT55 infused with 95 % porous copper foam, maximizing thermal energy storage. Additionally, higher porosity increases melting time due to the larger PCM volume, while PCM selection significantly impacts thermal efficiency. Heat sink size also influences foam material effectiveness, affecting heat transfer and fluid flow dynamics.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"30 ","pages":"Article 101512"},"PeriodicalIF":0.0,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145681094","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-21DOI: 10.1016/j.ijft.2025.101457
Pareekshith G. Bhat , Ali J. Chamkha , Nityanand P. Pai , Likhitha Nayak , Sampath Kumar V.S. , Devaki B. , Akshay Kumar , Ashwin Kumar Devaraj
The present study aims to theoretically investigate the impact of viscous dissipation on the behavior of heat transfer in the flow of ethylene glycol (EG)-based Graphene–Copper hybrid nanofluid (HNF). Furthermore, the nanofluid is assumed to be flowing through a channel of squeezing parallel disks under the combined effects of thermal radiation and external magnetic field. Moreover, it is considered that the impermeable upper disk approaches and dilates from the stationary lower porous disk through which the injection or suction takes place. The non-linear conservation equations that govern the flow and heat are translated into non-linear ordinary differential equations (ODEs) using suitable similarity transformations. Further, the obtained ODEs are approached by an elegant semi-analytical technique, the Homotopy perturbation method, in order to attain an approximate solution. In addition to the semi-analytical solution, the considered model is approached by the 4th order Runge–Kutta method, a well-known numerical technique, in order to compare the solutions obtained by two independent techniques. This investigation mainly highlights on analyzing the velocity distribution profile, coefficient of skin friction, temperature field, and Nusselt number for distinct pertinent physical parameters. From the figures, it is derived that the temperature profile rises with an increment in the Eckert number. However, it is noticed that a rise in the radiation parameter results in the temperature distribution to retard as the disks dilate in the suction case. Furthermore, it is perceived from the tables that the magnitude of the Nusselt number increases with elevation in the radiation parameter. Moreover, it can be concluded from the results that the solutions obtained from the two techniques are in good harmony.
{"title":"Thermally radiated heat transfer analysis on the viscous dissipated MHD EG-based copper-graphene hybrid nanofluid flow between parallel disks","authors":"Pareekshith G. Bhat , Ali J. Chamkha , Nityanand P. Pai , Likhitha Nayak , Sampath Kumar V.S. , Devaki B. , Akshay Kumar , Ashwin Kumar Devaraj","doi":"10.1016/j.ijft.2025.101457","DOIUrl":"10.1016/j.ijft.2025.101457","url":null,"abstract":"<div><div>The present study aims to theoretically investigate the impact of viscous dissipation on the behavior of heat transfer in the flow of ethylene glycol (EG)-based Graphene–Copper hybrid nanofluid (HNF). Furthermore, the nanofluid is assumed to be flowing through a channel of squeezing parallel disks under the combined effects of thermal radiation and external magnetic field. Moreover, it is considered that the impermeable upper disk approaches and dilates from the stationary lower porous disk through which the injection or suction takes place. The non-linear conservation equations that govern the flow and heat are translated into non-linear ordinary differential equations (ODEs) using suitable similarity transformations. Further, the obtained ODEs are approached by an elegant semi-analytical technique, the Homotopy perturbation method, in order to attain an approximate solution. In addition to the semi-analytical solution, the considered model is approached by the 4th order Runge–Kutta method, a well-known numerical technique, in order to compare the solutions obtained by two independent techniques. This investigation mainly highlights on analyzing the velocity distribution profile, coefficient of skin friction, temperature field, and Nusselt number for distinct pertinent physical parameters. From the figures, it is derived that the temperature profile rises with an increment in the Eckert number. However, it is noticed that a rise in the radiation parameter results in the temperature distribution to retard as the disks dilate in the suction case. Furthermore, it is perceived from the tables that the magnitude of the Nusselt number increases with elevation in the radiation parameter. Moreover, it can be concluded from the results that the solutions obtained from the two techniques are in good harmony.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"30 ","pages":"Article 101457"},"PeriodicalIF":0.0,"publicationDate":"2025-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145362998","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-16DOI: 10.1016/j.ijft.2025.101451
Muhammad Ehsan Ullah , Syed Tauseef Saeed , Najla A. Mohammed , Muhammad Idress , Muhammad Nauman Aslam , Ilyas Khan , Osama Oqilat , Muhammad Sabaoon Khan
This comprehensive numerical study of three-dimensional Prandtl ternary ferrofluid flow over a stretching surface considers the combined effects of Darcy–Forchheimer drag, activation energy, thermal radiation, Brownian motion, thermophoresis, heat generation/absorption, porous media, mass diffusivity, and magnetohydrodynamics (MHD). Ferrofluid is created by dispersing copper (Cu), iron oxide (), and cobalt ferrite () nanoparticles in a water-based Prandtl fluid in order to enhance thermal conductivity and magnetic permeability. The model includes radiative and non-Fourier heat conduction for realistic thermal representation, while the Darcy–Forchheimer approach characterises linear and nonlinear resistance in porous structures. Convective boundary conditions are used to replicate realistic heat exchange at the surface.
The governing partial differential equations of mass, momentum, energy, and species concentration are reduced by similarity transformations into a system of nonlinear ordinary differential equations. For computational accuracy, the shooting technique is employed to numerically solve these equations. The study looks at the parametric impacts of radiation, heat source/sink, Schmidt number, activated energy, magnetic field strength, porosity, Forchheimer number, Brownian motion, and thermophoresis. In addition to assessments of skin friction, Nusselt number, and Sherwood number, the distributions of temperature, velocity, and concentration are examined using tabular and graphical results.
The results show that thermal radiation and thermophoresis improve thermal dispersion, but greater porosity and magnetic intensity reduce velocity because of greater resistance. Because of finite mass diffusivity, concentration falls with increasing Schmidt numbers and activation energy. For engineering systems incorporating magnetic nanofluids and porous media, this work offers insightful information on transport phenomena. These systems have applications in materials processing, thermal management, and biomedical engineering.
{"title":"Prandtl ternary nanofluid flow with MHD, Porosity, and thermal effects over a 3D stretching surface with convective boundary conditions","authors":"Muhammad Ehsan Ullah , Syed Tauseef Saeed , Najla A. Mohammed , Muhammad Idress , Muhammad Nauman Aslam , Ilyas Khan , Osama Oqilat , Muhammad Sabaoon Khan","doi":"10.1016/j.ijft.2025.101451","DOIUrl":"10.1016/j.ijft.2025.101451","url":null,"abstract":"<div><div>This comprehensive numerical study of three-dimensional Prandtl ternary ferrofluid flow over a stretching surface considers the combined effects of Darcy–Forchheimer drag, activation energy, thermal radiation, Brownian motion, thermophoresis, heat generation/absorption, porous media, mass diffusivity, and magnetohydrodynamics (MHD). Ferrofluid is created by dispersing copper (Cu), iron oxide (<span><math><mrow><mi>F</mi><msub><mrow><mi>e</mi></mrow><mrow><mn>3</mn></mrow></msub><msub><mrow><mi>O</mi></mrow><mrow><mn>4</mn></mrow></msub></mrow></math></span>), and cobalt ferrite (<span><math><mrow><mi>C</mi><mi>o</mi><mi>F</mi><msub><mrow><mi>e</mi></mrow><mrow><mn>2</mn></mrow></msub><msub><mrow><mi>O</mi></mrow><mrow><mn>4</mn></mrow></msub></mrow></math></span>) nanoparticles in a water-based Prandtl fluid in order to enhance thermal conductivity and magnetic permeability. The model includes radiative and non-Fourier heat conduction for realistic thermal representation, while the Darcy–Forchheimer approach characterises linear and nonlinear resistance in porous structures. Convective boundary conditions are used to replicate realistic heat exchange at the surface.</div><div>The governing partial differential equations of mass, momentum, energy, and species concentration are reduced by similarity transformations into a system of nonlinear ordinary differential equations. For computational accuracy, the shooting technique is employed to numerically solve these equations. The study looks at the parametric impacts of radiation, heat source/sink, Schmidt number, activated energy, magnetic field strength, porosity, Forchheimer number, Brownian motion, and thermophoresis. In addition to assessments of skin friction, Nusselt number, and Sherwood number, the distributions of temperature, velocity, and concentration are examined using tabular and graphical results.</div><div>The results show that thermal radiation and thermophoresis improve thermal dispersion, but greater porosity and magnetic intensity reduce velocity because of greater resistance. Because of finite mass diffusivity, concentration falls with increasing Schmidt numbers and activation energy. For engineering systems incorporating magnetic nanofluids and porous media, this work offers insightful information on transport phenomena. These systems have applications in materials processing, thermal management, and biomedical engineering.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"30 ","pages":"Article 101451"},"PeriodicalIF":0.0,"publicationDate":"2025-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145363000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this research is investigated flow of hybrid nanofluid of the Al2O3 and CuO based on water fluid and electromagnetic force between parallel plates with a heat source. In this model effect of Brownian motion on the effective thermal conductivity also is considered. The innovation in the present paper is that the meshless method of the radial basis function (RBF) for is used for governing equationsthe desired geometry. In this method, without using pre-determined meshing to discretize the domain, it turns the problem into a system of algebraic equations by only using the set of scattered points in the domain and its boundaries. The ability of the RBF method is shown in comparing it with the numerical method finite element method (FEM) to solve this problem, which is in good agreement. In order to evaluate the convergence analysis of the method, error estimations are made by a residual function denoted. The results represent that the vertical velocity of the hybrid nanofluid in is increased compared to the vertical velocity of the mono nanofluid, but in is not a significant difference in velocity. Furthermore, the thickness of the thermal boundary layer of the hybrid nanofluid decreases. Also, the horizontal velocity of the hybrid nanofluid decreases with the increase of squeeze number untile but for the results are the opposite which leads to the formation of the backflow phenomenon. Moreover, the velocity components of the hybrid nanofluid remain unaffected by an increasing heat source parameter while increasing the thermal boundary layer thickness.
{"title":"Investigating the MHD flow of hybrid nanofluid Al2O3 - CuO with brownian motion between two parallel plates using RBF","authors":"Elham Tayari , Leila Torkzadeh , Davood Domiri Ganji , Kazem Nouri","doi":"10.1016/j.ijft.2025.101458","DOIUrl":"10.1016/j.ijft.2025.101458","url":null,"abstract":"<div><div>In this research is investigated flow of hybrid nanofluid of the Al<sub>2</sub>O<sub>3</sub> and CuO based on water fluid and electromagnetic force between parallel plates with a heat source. In this model effect of Brownian motion on the effective thermal conductivity also is considered. The innovation in the present paper is that the meshless method of the radial basis function (RBF) for is used for governing equationsthe desired geometry. In this method, without using pre-determined meshing to discretize the domain, it turns the problem into a system of algebraic equations by only using the set of scattered points in the domain and its boundaries. The ability of the RBF method is shown in comparing it with the numerical method finite element method (FEM) to solve this problem, which is in good agreement. In order to evaluate the convergence analysis of the method, error estimations are made by a residual function denoted. The results represent that the vertical velocity of the hybrid nanofluid in <span><math><mrow><mi>Ha</mi><mo>=</mo><mn>0</mn></mrow></math></span> is increased compared to the vertical velocity of the mono nanofluid, but in <span><math><mrow><mi>Ha</mi><mo>=</mo><mn>8</mn></mrow></math></span> is not a significant difference in velocity. Furthermore, the thickness of the thermal boundary layer of the hybrid nanofluid decreases. Also, the horizontal velocity of the hybrid nanofluid decreases with the increase of squeeze number untile <span><math><mrow><mi>η</mi><mo><</mo><mn>0.5</mn></mrow></math></span> but for <span><math><mrow><mi>η</mi><mo>></mo><mn>0.5</mn></mrow></math></span> the results are the opposite which leads to the formation of the backflow phenomenon. Moreover, the velocity components of the hybrid nanofluid remain unaffected by an increasing heat source parameter while increasing the thermal boundary layer thickness.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"30 ","pages":"Article 101458"},"PeriodicalIF":0.0,"publicationDate":"2025-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145362467","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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