Compound parabolic collectors (CPCs) are potential solar thermal systems, but their performance is usually limited by restricted convective heat transfer within the absorber tube. Although nanofluids and internal inserts have been investigated individually, few efforts have been directed toward their combined use in CPCs. This experiment explores the synergistic effect of Al2O3–water nanofluid (1% vol.) and dual twisted tape inserts (DTI) with pitch ratios of 2, 3, and 4 on the performance of CPC. Important parameters such as absorbed heat flux, Nusselt number, and collector efficiency were quantified for various flow rates. Results indicate that at a pitch ratio of 2, the Nusselt number was boosted by a maximum of 365% and absorbed heat flux by 13.3% over water in a bare tube. Collector efficiency was enhanced by a maximum of 35.6%, with marginal increases in friction factor and pumping power. The enviro-economic analysis also exhibited CO2 emission reductions of up to 12.3% and a 15% reduced payback period compared to the reference system. These observations affirm that the integration of nanofluids with turbulence-generating inserts provides a viable route to boost CPC performance, with possible applications in industrial process heating, desalination, and other green thermal systems.
{"title":"Thermal and enviro-economic evaluation of a compound parabolic collector enhanced with Al2O3-water nanofluid and dual twisted inserts","authors":"Bhavin Mehta , Choon Kit Chan , Abhishek Swarnkar , Dattatraya Subhedar , Saurav Dixit , Subhav Singh","doi":"10.1016/j.ijft.2026.101575","DOIUrl":"10.1016/j.ijft.2026.101575","url":null,"abstract":"<div><div>Compound parabolic collectors (CPCs) are potential solar thermal systems, but their performance is usually limited by restricted convective heat transfer within the absorber tube. Although nanofluids and internal inserts have been investigated individually, few efforts have been directed toward their combined use in CPCs. This experiment explores the synergistic effect of Al<sub>2</sub>O<sub>3</sub>–water nanofluid (1% vol.) and dual twisted tape inserts (DTI) with pitch ratios of 2, 3, and 4 on the performance of CPC. Important parameters such as absorbed heat flux, Nusselt number, and collector efficiency were quantified for various flow rates. Results indicate that at a pitch ratio of 2, the Nusselt number was boosted by a maximum of 365% and absorbed heat flux by 13.3% over water in a bare tube. Collector efficiency was enhanced by a maximum of 35.6%, with marginal increases in friction factor and pumping power. The enviro-economic analysis also exhibited CO<sub>2</sub> emission reductions of up to 12.3% and a 15% reduced payback period compared to the reference system. These observations affirm that the integration of nanofluids with turbulence-generating inserts provides a viable route to boost CPC performance, with possible applications in industrial process heating, desalination, and other green thermal systems.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"32 ","pages":"Article 101575"},"PeriodicalIF":0.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147398259","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}
Nanofluid-cooled compact heat sinks are essential for thermal management of dense electronic and laboratory hardware operating under tight power-constrained pumping. Slotted pin-fin geometries are beneficial under limited pump capacity because they promote surface renewal and mixing while remaining compatible with laminar flow and reduced spatial requirement. The study addresses the lack of a property-consistent, experimentally anchored framework that couples slot length, effective Reynolds number, and nanofluid loading for laminar slotted pin-fin heat sinks under constant pumping power. The objective of the investigation is to establish engineering correlations and operating maps for oxide–water nanofluids in compact slotted pin-fin arrays based on a constant-power performance evaluation criterion. Experiments and CFD-used response-surface modelling were carried out in a closed-loop laminar rig using Al₂O₃-, SiO₂-, and CuO–water nanofluids, with slot length, effective Reynolds number, and nanoparticle volume fraction varied systematically and analyzed through a quadratic response surface fitted to Nusselt number, pressure drop, and a performance evaluation criterion. Experiments with Al₂O₃ loadings of about 0.6–0.7 vol% at Reynolds numbers near 1200–1500 and slot lengths of 9–11 mm yielded Nusselt number increases of 14–18% and pressure-drop rises of 7–9%; these quantified changes are interpreted as performance evaluation criteria up to about 1.08–1.09 relative to water. Across the design space, practical optima fell within a corridor of 0.4–0.8 vol% and intermediate slot lengths, and the associated parity plots exhibited coefficients of determination above 0.99 for Nusselt number and pressure drop, indicating that the surrogate model is statistically robust. These findings provide a quantitative basis for selecting coolant composition, flow rate, and slot geometry in laminar nanofluid-cooled slotted pin-fin heat sinks to enhance energy efficiency and thermal reliability under constant pumping-power constraints. The work also defines a roadmap for future optimization of hybrid nanofluids, alternative interrupted-fin concepts, and long-term stability assessment of nanofluid suspensions.
{"title":"Multi-objective engineering optimization of nanofluid coolants in compact slotted pin-fin heat exchangers","authors":"Wasurat Bunpheng , Ratchagaraja Dhairiyasamy , Deekshant Varshney , Subhav Singh , Choon Kit Chan , Elangovan Murugesan","doi":"10.1016/j.ijft.2026.101588","DOIUrl":"10.1016/j.ijft.2026.101588","url":null,"abstract":"<div><div>Nanofluid-cooled compact heat sinks are essential for thermal management of dense electronic and laboratory hardware operating under tight power-constrained pumping. Slotted pin-fin geometries are beneficial under limited pump capacity because they promote surface renewal and mixing while remaining compatible with laminar flow and reduced spatial requirement. The study addresses the lack of a property-consistent, experimentally anchored framework that couples slot length, effective Reynolds number, and nanofluid loading for laminar slotted pin-fin heat sinks under constant pumping power. The objective of the investigation is to establish engineering correlations and operating maps for oxide–water nanofluids in compact slotted pin-fin arrays based on a constant-power performance evaluation criterion. Experiments and CFD-used response-surface modelling were carried out in a closed-loop laminar rig using Al₂O₃-, SiO₂-, and CuO–water nanofluids, with slot length, effective Reynolds number, and nanoparticle volume fraction varied systematically and analyzed through a quadratic response surface fitted to Nusselt number, pressure drop, and a performance evaluation criterion. Experiments with Al₂O₃ loadings of about 0.6–0.7 vol% at Reynolds numbers near 1200–1500 and slot lengths of 9–11 mm yielded Nusselt number increases of 14–18% and pressure-drop rises of 7–9%; these quantified changes are interpreted as performance evaluation criteria up to about 1.08–1.09 relative to water. Across the design space, practical optima fell within a corridor of 0.4–0.8 vol% and intermediate slot lengths, and the associated parity plots exhibited coefficients of determination above 0.99 for Nusselt number and pressure drop, indicating that the surrogate model is statistically robust. These findings provide a quantitative basis for selecting coolant composition, flow rate, and slot geometry in laminar nanofluid-cooled slotted pin-fin heat sinks to enhance energy efficiency and thermal reliability under constant pumping-power constraints. The work also defines a roadmap for future optimization of hybrid nanofluids, alternative interrupted-fin concepts, and long-term stability assessment of nanofluid suspensions.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"32 ","pages":"Article 101588"},"PeriodicalIF":0.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147398261","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 : 2026-03-01Epub Date: 2026-02-21DOI: 10.1016/j.ijft.2026.101590
Fateme Nadalinia Chari, Davood Domiri Ganji, Mehdi Mahboobtosi
The aim of this study is to analyze the magnetohydrodynamic (MHD) behavior of Casson penta hybrid nanofluids (PHNFs) squeezed between two parallel plates, considering the effects of chemical reactions and thermal radiation. The Casson PHNF is composed of five nanomaterials: molybdenum disulfide, copper, magnesium oxide, aluminum oxide, and silver, each selected for its unique properties that enhance thermal conductivity, fluid behavior, and heat transfer. Partial differential equations (PDE) are converted into ordinary differential equations (ODE) using appropriate transformations and solved using Akbari Ganji Method (AGM). The novelty of this research is the use of PHNF as a new class of nanofluids and also the solution of the equations of the problem using the AGM method. The results indicate that the velocity is reduced by the rising squeeze number, Casson fluid parameter, and Hartmann number. Temperature profile is boosted by the rising Eckert number, while the elevated concentrations of nanoparticles reduce the temperature profile. Concentration profile is reduced by the rising Schmidt number. The results show that PHNF reduces the skin friction coefficient and Schroeder number and increases the Nusselt number compared to THNF. Using PHNF instead of THNF at constant parameters reduces the skin friction coefficient by 3.69%. At constant values of parameters, using PHNF instead of THNF improves the Nusselt number by 28.16%. Also, increasing Schmidt number from 1.5 to 2 increases the Sherwood number by 27.84%. The applications of Casson PHNFs are promising in advanced cooling systems, energy storage, and biomedical engineering, where efficient thermal management and friction reduction are critical.
{"title":"Computational enhancement of radiative and reactive magneto-thermal performance with CPHNF: A python-assisted analytical framework for biomedical applications","authors":"Fateme Nadalinia Chari, Davood Domiri Ganji, Mehdi Mahboobtosi","doi":"10.1016/j.ijft.2026.101590","DOIUrl":"10.1016/j.ijft.2026.101590","url":null,"abstract":"<div><div>The aim of this study is to analyze the magnetohydrodynamic (MHD) behavior of Casson penta hybrid nanofluids (PHNFs) squeezed between two parallel plates, considering the effects of chemical reactions and thermal radiation. The Casson PHNF is composed of five nanomaterials: molybdenum disulfide, copper, magnesium oxide, aluminum oxide, and silver, each selected for its unique properties that enhance thermal conductivity, fluid behavior, and heat transfer. Partial differential equations (PDE) are converted into ordinary differential equations (ODE) using appropriate transformations and solved using Akbari Ganji Method (AGM). The novelty of this research is the use of PHNF as a new class of nanofluids and also the solution of the equations of the problem using the AGM method. The results indicate that the velocity is reduced by the rising squeeze number, Casson fluid parameter, and Hartmann number. Temperature profile is boosted by the rising Eckert number, while the elevated concentrations of nanoparticles reduce the temperature profile. Concentration profile is reduced by the rising Schmidt number. The results show that PHNF reduces the skin friction coefficient and Schroeder number and increases the Nusselt number compared to THNF. Using PHNF instead of THNF at constant parameters reduces the skin friction coefficient by 3.69%. At constant values of parameters, using PHNF instead of THNF improves the Nusselt number by 28.16%. Also, increasing Schmidt number from 1.5 to 2 increases the Sherwood number by 27.84%. The applications of Casson PHNFs are promising in advanced cooling systems, energy storage, and biomedical engineering, where efficient thermal management and friction reduction are critical.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"32 ","pages":"Article 101590"},"PeriodicalIF":0.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147398264","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 : 2026-03-01Epub Date: 2026-01-12DOI: 10.1016/j.ijft.2026.101557
Mohammad Sameti , Sahar Ghasemipour , Ebrahim Najafi
Superhydrophobic surfaces are characterized by low surface energy and micro- to nano-scale roughness. These properties cause fluids to slide over the surface, thereby reducing drag and adhesion, and resulting in a lower drag coefficient. The drag coefficient, adhesion, and shear stress are critical parameters in airfoil performance evaluation. In this study, the effects of slip length and superhydrophobic boundary conditions on the aerodynamic performance of the SC(2)-410 airfoil were investigated numerically at various Mach numbers and altitudes. Superhydrophobic boundary conditions reduce humidity-induced adhesion on the airfoil surface. Comparative analyses were conducted between slip and no-slip boundary conditions, focusing on shear stress as well as drag and lift coefficients. Superhydrophobicity was found to decrease both shear stress and fluid adhesion to the surface. As slip length increases, the drag coefficient decreases while the lift coefficient increases, compared to conventional surfaces. When the Mach number increases from 0.6 to 0.8, the reductions in drag and enhancements in lift become more pronounced. Additionally, altitude significantly affects the calculation of lift and drag coefficients by influencing relative humidity. As altitude increases, relative humidity tends to rise, which leads to an increase in the drag coefficient and a decrease in the lift coefficient. Superhydrophobic surfaces help mitigate the negative impact of humidity on aerodynamic performance.
{"title":"Superhydrophobic surfaces on supercritical airfoils: mitigating ice formation and enhancing performance","authors":"Mohammad Sameti , Sahar Ghasemipour , Ebrahim Najafi","doi":"10.1016/j.ijft.2026.101557","DOIUrl":"10.1016/j.ijft.2026.101557","url":null,"abstract":"<div><div>Superhydrophobic surfaces are characterized by low surface energy and micro- to nano-scale roughness. These properties cause fluids to slide over the surface, thereby reducing drag and adhesion, and resulting in a lower drag coefficient. The drag coefficient, adhesion, and shear stress are critical parameters in airfoil performance evaluation. In this study, the effects of slip length and superhydrophobic boundary conditions on the aerodynamic performance of the SC(2)-410 airfoil were investigated numerically at various Mach numbers and altitudes. Superhydrophobic boundary conditions reduce humidity-induced adhesion on the airfoil surface. Comparative analyses were conducted between slip and no-slip boundary conditions, focusing on shear stress as well as drag and lift coefficients. Superhydrophobicity was found to decrease both shear stress and fluid adhesion to the surface. As slip length increases, the drag coefficient decreases while the lift coefficient increases, compared to conventional surfaces. When the Mach number increases from 0.6 to 0.8, the reductions in drag and enhancements in lift become more pronounced. Additionally, altitude significantly affects the calculation of lift and drag coefficients by influencing relative humidity. As altitude increases, relative humidity tends to rise, which leads to an increase in the drag coefficient and a decrease in the lift coefficient. Superhydrophobic surfaces help mitigate the negative impact of humidity on aerodynamic performance.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"32 ","pages":"Article 101557"},"PeriodicalIF":0.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146078825","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 : 2026-03-01Epub Date: 2026-01-26DOI: 10.1016/j.ijft.2026.101574
Chengyu Lu , Rasool Erfani , Lena Ciric , Tohid Erfani
Plasma-activated water (PAW) is an innovative and environmentally friendly sterilisation method that leverages reactive nitrogen species (RNS) and reactive oxygen species (ROS) to eliminate bacteria and other pathogens without relying on chemical additives or high-energy inputs. This study focuses on nanosecond-pulse non-thermal plasma, an emerging green technology with limited research, to investigate how liquid volume, PAW production time, and bacterial treatment time influence RNS and ROS levels. Using a fixed power setting, we tested 100 mL and 200 mL PAW volumes and evaluated their efficacy in sterilizing Escherichia coli K12 bacterial cells after 5, 10, and 15 min of contact. The results demonstrated that 100 mL PAW treated for 4 min achieved the highest levels of nitrite and hydrogen peroxide, resulting in optimal sterilisation performance. In contrast, the duration of bacterial contact with PAW had a lesser impact. These findings provide new insights into optimising plasma-based sterilisation techniques with minimal environmental impact, offering practical guidance for sustainable applications in healthcare and industry. By showcasing how volume and discharge time can enhance the efficiency of PAW production, this research contributes to advancing net-zero technologies by reducing reliance on energy-intensive sterilisation methods, aligning with global efforts to achieve the UN Sustainable Development Goals.
{"title":"The impact of nanosecond-pulsed non-thermal plasma-activated water on Escherichia coliK12 disinfection under various conditions","authors":"Chengyu Lu , Rasool Erfani , Lena Ciric , Tohid Erfani","doi":"10.1016/j.ijft.2026.101574","DOIUrl":"10.1016/j.ijft.2026.101574","url":null,"abstract":"<div><div>Plasma-activated water (PAW) is an innovative and environmentally friendly sterilisation method that leverages reactive nitrogen species (RNS) and reactive oxygen species (ROS) to eliminate bacteria and other pathogens without relying on chemical additives or high-energy inputs. This study focuses on nanosecond-pulse non-thermal plasma, an emerging green technology with limited research, to investigate how liquid volume, PAW production time, and bacterial treatment time influence RNS and ROS levels. Using a fixed power setting, we tested 100 mL and 200 mL PAW volumes and evaluated their efficacy in sterilizing <em>Escherichia coli</em> K12 bacterial cells after 5, 10, and 15 min of contact. The results demonstrated that 100 mL PAW treated for 4 min achieved the highest levels of nitrite and hydrogen peroxide, resulting in optimal sterilisation performance. In contrast, the duration of bacterial contact with PAW had a lesser impact. These findings provide new insights into optimising plasma-based sterilisation techniques with minimal environmental impact, offering practical guidance for sustainable applications in healthcare and industry. By showcasing how volume and discharge time can enhance the efficiency of PAW production, this research contributes to advancing net-zero technologies by reducing reliance on energy-intensive sterilisation methods, aligning with global efforts to achieve the UN Sustainable Development Goals.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"32 ","pages":"Article 101574"},"PeriodicalIF":0.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146174113","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 : 2026-03-01Epub Date: 2026-02-02DOI: 10.1016/j.ijft.2026.101576
Abha Singh , Umar Nazir , M.A. Ahmed , Seham M. Al-Mekhlafi , Hakim AL Garalleh , Ahmed M. Galal
The current model describes the dual solutions in a non-Newtonian fluid on a shrinking and stretching needle, which gives applications in the real world. Such as polymer extrusion, biomedical processes, fiber coating, electronic devices and cooling process. The motion of multiple nanofluids is produced when the needle moves in both directions (stretching and shrinking). The Soret and Dufour effects are analyzed in mass and energy equations. The phenomenon of activation energy is analyzed. The theory of slip conditions is used. The correlation of tetra-hybrid nanofluid is considered to analyze the mechanism of the thermal and cooling process. The role of gyrotactic microorganisms is considered with activation energy. The derived form of ODEs is obtained via transformations. The finite element method is used to simulate the dual solution. Heat transfer rate decreases with a change of Soret number, while mass diffusion rate is a decreasing function with a change of Schmidt number. The density of the nanofluids grows when the Péclet number is enhanced, but the density of the nanofluids declines with higher values of the velocity fields because of large values of the micropolar parameter (), bioconvection Rayleigh number () and buoyancy ratio number. When the size of the needle enhances, Nusselt, Sherwood and shear stress numbers are enhanced.
{"title":"Computational study of tetra hybrid nanofluid in micropolar fluid on shrinking/stretching needle: A dual solution study","authors":"Abha Singh , Umar Nazir , M.A. Ahmed , Seham M. Al-Mekhlafi , Hakim AL Garalleh , Ahmed M. Galal","doi":"10.1016/j.ijft.2026.101576","DOIUrl":"10.1016/j.ijft.2026.101576","url":null,"abstract":"<div><div>The current model describes the dual solutions in a non-Newtonian fluid on a shrinking and stretching needle, which gives applications in the real world. Such as polymer extrusion, biomedical processes, fiber coating, electronic devices and cooling process. The motion of multiple nanofluids is produced when the needle moves in both directions (stretching and shrinking). The Soret and Dufour effects are analyzed in mass and energy equations. The phenomenon of activation energy is analyzed. The theory of slip conditions is used. The correlation of tetra-hybrid nanofluid is considered to analyze the mechanism of the thermal and cooling process. The role of gyrotactic <span><span>microorganism</span><svg><path></path></svg></span>s is considered with activation energy. The derived form of ODEs is obtained via transformations. The finite element method is used to simulate the dual solution. Heat transfer rate decreases with a change of Soret number, while mass diffusion rate is a decreasing function with a change of Schmidt number. The density of the nanofluids grows when the Péclet number is enhanced, but the density of the nanofluids declines with higher values of the velocity fields because of large values of the micropolar parameter (<span><math><mi>k</mi></math></span>), bioconvection <span><span>Rayleigh numbe</span><svg><path></path></svg></span>r (<span><math><msub><mi>R</mi><mi>B</mi></msub></math></span>) and buoyancy ratio number. When the size of the needle enhances, Nusselt, Sherwood and shear stress numbers are enhanced.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"32 ","pages":"Article 101576"},"PeriodicalIF":0.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146174112","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}
Understanding the transport and near-wall dynamics of nanoparticles in arterial bifurcations is critical for elucidating atherogenesis and optimising nanotherapeutic design. This study systematically investigated the behaviour of nanoparticles (18–200 nm) in carotid artery bifurcations under physiologically realistic pulsatile conditions, using a coupled CFD–FSI–DPM framework. The influence of particle size, injection site, blood rheology (original and modified Carreau models), arterial wall mechanics (rigid, one-way, and two-way FSI), and endothelial surface roughness was evaluated on key hemodynamic parameters, including Particle Residence Time (PRT), wall shear stress, vorticity, and flow patterns. Boundary-layer injections consistently prolonged particle residence, with small (18 nm) nanoparticles showing high endothelial penetration potential and large (200 nm) particles achieving maximal near-wall retention (∼1.2 %). Localised bifurcation regions further amplified residence times, highlighting the critical role of disturbed near-wall hemodynamics. Vessel compliance enhanced near-wall trapping, with two-way FSI predicting peak arterial displacements (∼1.43 mm) and Von Mises stresses (∼0.04 MPa), while one-way FSI nearly doubled particle residence compared with rigid-wall models. The modified Carreau model maintained higher viscosity in low-shear regions, producing broader wall shear stress distributions (∼19 Pa) and smoother flow, which prolonged early particle retention (∼4.46 % at 0.5 s). Surface roughness amplified retention, physiological (∼1.1 µm) and pathological (∼10 µm) roughness promoting particle accumulation (∼7.6–9.8 %). Overall, nanoparticle transport in bifurcating arterial flows is governed by the coupled effects of flow unsteadiness, vascular mechanics, non-Newtonian rheology, particle size, injection strategy, and wall microtopography. The validated multiphysics platform provides mechanistic insight into LDL entrapment and plaque initiation and offers design-relevant guidance for nanoparticle-based therapeutics and patient-specific analyses.
{"title":"Multiphysics CFD–FSI–DPM analysis of nanoparticle transport and near-wall retention in carotid artery bifurcations","authors":"Chue Shwe Sin Kyi , Jetsadaporn Priyadumkol , Arom Boekfah , Kavin Karunratanakul , Mongkol Kaewbumrung , Wiroj Limtrakarn , Sureerat Suwatcharangkoon , Sherman C.P. Cheung , Chakrit Suvanjumrat , Machimontorn Promtong","doi":"10.1016/j.ijft.2026.101593","DOIUrl":"10.1016/j.ijft.2026.101593","url":null,"abstract":"<div><div>Understanding the transport and near-wall dynamics of nanoparticles in arterial bifurcations is critical for elucidating atherogenesis and optimising nanotherapeutic design. This study systematically investigated the behaviour of nanoparticles (18–200 nm) in carotid artery bifurcations under physiologically realistic pulsatile conditions, using a coupled CFD–FSI–DPM framework. The influence of particle size, injection site, blood rheology (original and modified Carreau models), arterial wall mechanics (rigid, one-way, and two-way FSI), and endothelial surface roughness was evaluated on key hemodynamic parameters, including Particle Residence Time (PRT), wall shear stress, vorticity, and flow patterns. Boundary-layer injections consistently prolonged particle residence, with small (18 nm) nanoparticles showing high endothelial penetration potential and large (200 nm) particles achieving maximal near-wall retention (∼1.2 %). Localised bifurcation regions further amplified residence times, highlighting the critical role of disturbed near-wall hemodynamics. Vessel compliance enhanced near-wall trapping, with two-way FSI predicting peak arterial displacements (∼1.43 mm) and Von Mises stresses (∼0.04 MPa), while one-way FSI nearly doubled particle residence compared with rigid-wall models. The modified Carreau model maintained higher viscosity in low-shear regions, producing broader wall shear stress distributions (∼19 Pa) and smoother flow, which prolonged early particle retention (∼4.46 % at 0.5 s). Surface roughness amplified retention, physiological (∼1.1 µm) and pathological (∼10 µm) roughness promoting particle accumulation (∼7.6–9.8 %). Overall, nanoparticle transport in bifurcating arterial flows is governed by the coupled effects of flow unsteadiness, vascular mechanics, non-Newtonian rheology, particle size, injection strategy, and wall microtopography. The validated multiphysics platform provides mechanistic insight into LDL entrapment and plaque initiation and offers design-relevant guidance for nanoparticle-based therapeutics and patient-specific analyses.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"32 ","pages":"Article 101593"},"PeriodicalIF":0.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147398212","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 : 2026-03-01Epub Date: 2026-01-16DOI: 10.1016/j.ijft.2026.101559
Osama M. Ibrahim, Nawaf F. Aljuwayhel
Directional Solvent Extraction (DSE) is a promising desalination process that can produce fresh water from saline water using low-temperature heat sources. Amines, fatty acids, and ionic liquids were proposed as potential directional solvents—these solvents and seawater form liquid–liquid binary mixtures in a two-phase immiscible system. The energy and exergy analyses of the DSE desalination processes require accurate and consistent thermodynamic properties of these liquid–liquid mixtures. This paper presents a systematic framework for evaluating the thermodynamic properties of two-phase, liquid–liquid immiscible binary solutions consisting of seawater and a potential directional solvent. The property prediction framework includes two main steps: (1) a fundamental Gibbs free energy equation is utilized to evaluate the thermodynamic properties of the pure liquid solvent, while pure water and seawater properties were determined using existing correlations; and (2) The Non-Random Two-Liquid (NRTL) excess Gibbs energy model was used membranes to capture deviations of water–solvent mixtures from ideal solution behavior. The thermodynamic properties of two-phase immiscible mixtures of seawater and octanoic acid as a directional solvent were then determined using the methodology described in this paper. Finally, the thermodynamic properties of liquid–liquid immiscible mixtures of octanoic acid and seawater were used to analyze a basic example of a DSE desalination system.
{"title":"Thermodynamic properties of liquid–liquid immiscible mixtures of seawater and directional solvents for the energy and exergy evaluation of DSE desalination systems","authors":"Osama M. Ibrahim, Nawaf F. Aljuwayhel","doi":"10.1016/j.ijft.2026.101559","DOIUrl":"10.1016/j.ijft.2026.101559","url":null,"abstract":"<div><div>Directional Solvent Extraction (DSE) is a promising desalination process that can produce fresh water from saline water using low-temperature heat sources. Amines, fatty acids, and ionic liquids were proposed as potential directional solvents—these solvents and seawater form liquid–liquid binary mixtures in a two-phase immiscible system. The energy and exergy analyses of the DSE desalination processes require accurate and consistent thermodynamic properties of these liquid–liquid mixtures. This paper presents a systematic framework for evaluating the thermodynamic properties of two-phase, liquid–liquid immiscible binary solutions consisting of seawater and a potential directional solvent. The property prediction framework includes two main steps: (1) a fundamental Gibbs free energy equation is utilized to evaluate the thermodynamic properties of the pure liquid solvent, while pure water and seawater properties were determined using existing correlations; and (2) The Non-Random Two-Liquid (NRTL) excess Gibbs energy model was used membranes to capture deviations of water–solvent mixtures from ideal solution behavior. The thermodynamic properties of two-phase immiscible mixtures of seawater and octanoic acid as a directional solvent were then determined using the methodology described in this paper. Finally, the thermodynamic properties of liquid–liquid immiscible mixtures of octanoic acid and seawater were used to analyze a basic example of a DSE desalination system.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"32 ","pages":"Article 101559"},"PeriodicalIF":0.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146024678","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}
This study investigates the thermal performance of four innovative insulation materials phase change materials (PCM), aerogel, vacuum insulated panels (VIP), and autoclaved aerated concrete (AAC)for cold-climate buildings in Varzaqan, Iran. Using 24 years of hourly climate data, five wall configurations (uninsulated reference, PCM, aerogel, VIP, and AAC) were simulated in EnergyPlus, with PCM behavior modeled via an enthalpy-temperature phase change routine. Key indicators included annual heating energy demand, wall surface temperature stability, time lag, and comfort hours. Results show that VIP achieved the greatest reduction in annual heating demand (36.6%), followed by aerogel (29.5%), AAC (24.1%), and PCM (21.4%). PCM and AAC provided substantial thermal inertia, delaying heat transfer by150–180 min and90–120 min, respectively, thereby enhancing night-time comfort. In contrast, VIP and aerogel maintained nearly constant surface temperatures (fluctuations <3ºC). Hybrid configurations offered the most favorable outcomes: a VIP+PCM wall reduced annual demand by 40.3% and achieved∼6510 comfort hours (74% of the year). Passive solar gains, when integrated into the analysis, improved PCM effectiveness by ∼12% in sunny winter days, while AAC showed moderate benefit and VIP remained largely unaffected. Sensitivity analysis highlighted VIP’s vulnerability to vacuum loss ∼12% performance degradation and AAC’s dependence on moisture, whereas aerogel and PCM proved more robust. Overall, the findings underscore the complementarity of ultra-low conductivity materials (VIP, aerogel) and high thermal mass/storage materials (PCM,AAC). While economic and practical barriers remain, hybrid approaches represent a promising pathway to significantly reducing heating energy demand and improving thermal comfort in cold climates.
{"title":"Evaluation of Thermal Performance of Innovative Insulation Materials for Energy-Efficient Buildings in Cold Climates","authors":"Ali Maboudi Reveshti , Farid Hosseini Mansoub , Jhila Nasiri Reveshti , Karim Farajeyan Bonab","doi":"10.1016/j.ijft.2025.101544","DOIUrl":"10.1016/j.ijft.2025.101544","url":null,"abstract":"<div><div>This study investigates the thermal performance of four innovative insulation materials phase change materials (PCM), aerogel, vacuum insulated panels (VIP), and autoclaved aerated concrete (AAC)for cold-climate buildings in Varzaqan, Iran. Using 24 years of hourly climate data, five wall configurations (uninsulated reference, PCM, aerogel, VIP, and AAC) were simulated in EnergyPlus, with PCM behavior modeled via an enthalpy-temperature phase change routine. Key indicators included annual heating energy demand, wall surface temperature stability, time lag, and comfort hours. Results show that VIP achieved the greatest reduction in annual heating demand (36.6%), followed by aerogel (29.5%), AAC (24.1%), and PCM (21.4%). PCM and AAC provided substantial thermal inertia, delaying heat transfer by150–180 min and90–120 min, respectively, thereby enhancing night-time comfort. In contrast, VIP and aerogel maintained nearly constant surface temperatures (fluctuations <3ºC). Hybrid configurations offered the most favorable outcomes: a VIP+PCM wall reduced annual demand by 40.3% and achieved∼6510 comfort hours (74% of the year). Passive solar gains, when integrated into the analysis, improved PCM effectiveness by ∼12% in sunny winter days, while AAC showed moderate benefit and VIP remained largely unaffected. Sensitivity analysis highlighted VIP’s vulnerability to vacuum loss ∼12% performance degradation and AAC’s dependence on moisture, whereas aerogel and PCM proved more robust. Overall, the findings underscore the complementarity of ultra-low conductivity materials (VIP, aerogel) and high thermal mass/storage materials (PCM,AAC). While economic and practical barriers remain, hybrid approaches represent a promising pathway to significantly reducing heating energy demand and improving thermal comfort in cold climates.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"32 ","pages":"Article 101544"},"PeriodicalIF":0.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146024815","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 : 2026-03-01Epub Date: 2026-01-23DOI: 10.1016/j.ijft.2026.101569
Nayef Ghasem
Methyl tert‑butyl ether (MTBE) was widely utilized as a standard additive in high-octane gasoline due to its ability to improve combustion efficiency and provide effective knock resistance. However, its extensive use resulted in significant environmental concerns, prompting its prohibition in numerous countries. As an alternative, di-isobutylene (DIB), derived from the selective oligomerization of isobutylene, can be hydrogenated to produce high-quality, clean gasoline. This indirect alkylation process yields a blend rich in isooctane, characterized by a high-octane number and low vapor pressure while freeing sulfur, benzene, and aromatic compounds. This study provides an in-depth modeling and simulation analysis of a novel gas–liquid–solid circulating mini-fluidized bed reactor designed for isobutylene polymerization. A detailed hydrodynamic and kinetic model was created using COMSOL Multiphysics version 6.3 to investigate how operating parameters affect isobutylene conversion and di-isobutylene yield. The simulation outcomes were thoroughly validated by comparing them to experimental data from a mini circulating fluidized bed reactor with a 10 mm inner diameter, 260 mm riser, and 160 mm downers. The results indicate that the circulating mini-fluidized bed can achieve high isobutylene conversion and high di-isobutylene yield. This improved performance is linked to the synergistic effects of solid particles and gas bubbles, which enhance the specific surface area of the reactor and promote advantageous hydrodynamic alterations. These findings validate the efficacy of the simulation framework and underscore the reactor’s potential for optimizing industrial polymerization processes.
甲基叔丁基醚（MTBE）由于能够提高燃烧效率和提供有效的抗爆性能，被广泛用作高辛烷值汽油的标准添加剂。然而，它的广泛使用引起了严重的环境问题，促使许多国家禁止使用它。二异丁烯（DIB）是由异丁烯的选择性低聚反应衍生而来，可以加氢生产高质量、清洁的汽油。这种间接烷基化过程产生了富含异辛烷的混合物，其特点是辛烷值高，蒸气压低，同时释放出硫、苯和芳香族化合物。本文对异丁烯聚合用新型气-液-固循环微型流化床反应器进行了深入的建模和仿真分析。利用COMSOL Multiphysics version 6.3建立了详细的流体力学和动力学模型，研究了操作参数对异丁烯转化率和二异丁烯收率的影响。将模拟结果与内径为10 mm、提升管为260 mm、下沉管为160 mm的小型循环流化床反应器的实验数据进行了比较，验证了模拟结果的有效性。结果表明，循环微型流化床可以实现高异丁烯转化率和高二异丁烯收率。这种性能的提高与固体颗粒和气泡的协同作用有关，它们增强了反应器的比表面积，促进了有利的水动力变化。这些发现验证了模拟框架的有效性，并强调了反应器优化工业聚合过程的潜力。
{"title":"Modeling and simulation of isobutylene polymerization in gas-liquid-solid circulating fluidized bed reactor","authors":"Nayef Ghasem","doi":"10.1016/j.ijft.2026.101569","DOIUrl":"10.1016/j.ijft.2026.101569","url":null,"abstract":"<div><div>Methyl tert‑butyl ether (MTBE) was widely utilized as a standard additive in high-octane gasoline due to its ability to improve combustion efficiency and provide effective knock resistance. However, its extensive use resulted in significant environmental concerns, prompting its prohibition in numerous countries. As an alternative, di-isobutylene (DIB), derived from the selective oligomerization of isobutylene, can be hydrogenated to produce high-quality, clean gasoline. This indirect alkylation process yields a blend rich in isooctane, characterized by a high-octane number and low vapor pressure while freeing sulfur, benzene, and aromatic compounds. This study provides an in-depth modeling and simulation analysis of a novel gas–liquid–solid circulating mini-fluidized bed reactor designed for isobutylene polymerization. A detailed hydrodynamic and kinetic model was created using COMSOL Multiphysics version 6.3 to investigate how operating parameters affect isobutylene conversion and di-isobutylene yield. The simulation outcomes were thoroughly validated by comparing them to experimental data from a mini circulating fluidized bed reactor with a 10 mm inner diameter, 260 mm riser, and 160 mm downers. The results indicate that the circulating mini-fluidized bed can achieve high isobutylene conversion and high di-isobutylene yield. This improved performance is linked to the synergistic effects of solid particles and gas bubbles, which enhance the specific surface area of the reactor and promote advantageous hydrodynamic alterations. These findings validate the efficacy of the simulation framework and underscore the reactor’s potential for optimizing industrial polymerization processes.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"32 ","pages":"Article 101569"},"PeriodicalIF":0.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146078918","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}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号