International Journal of Thermofluids最新文献

{"title":"Comparative experimental evaluation of wood charcoal and cocopeat fillers in a pyramid-shaped solar still for enhanced desalination performance","authors":"Arunkumar H. S ,&nbsp;Avinash K. Hegde ,&nbsp;K.Vasudeva Karanth ,&nbsp;Younes Amini ,&nbsp;Madhwesh N","doi":"10.1016/j.ijft.2025.101447","DOIUrl":"10.1016/j.ijft.2025.101447","url":null,"abstract":"<div><div>Freshwater scarcity remains a persistent challenge in arid and coastal regions, necessitating cost-effective and energy-efficient desalination solutions. This study presents an experimental performance evaluation of a pyramid-shaped solar still (PSS) enhanced with porous fillers cocopeat and wood charcoal to improve distillate productivity. The PSS, fabricated with a black-coated stainless-steel basin and insulated with thermocol and foam, was operated using both tap and saline water under coastal climatic conditions. Incorporation of fillers significantly improved the thermal regime and overall yield compared to the base model. The charcoal–saline water configuration exhibited the best performance, achieving a daily distillate yield of 950 mL and a thermal efficiency of 23.17 %, representing a 34 % enhancement over the base saline-water case (17.3 %). Cocopeat improved heat retention but resulted in slower evaporation and lower yield. The enhanced absorptivity of charcoal promoted higher basin water temperature and better energy utilization. All configurations produced very soft distillate (10–20 mg/L as CaCO₃), meeting WHO potable water standards. The findings demonstrate that low-cost filler materials, particularly wood charcoal, can significantly augment the thermal and distillation efficiency of PSS, highlighting their suitability for decentralized desalination in resource-constrained regions.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"30 ","pages":"Article 101447"},"PeriodicalIF":0.0,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145321220","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}

{"title":"Analytical and numerical investigation of MHD viscoelastic flow with heat and mass transfer in an asymmetric wavy channel","authors":"Ali Ahmadi Azar","doi":"10.1016/j.ijft.2025.101456","DOIUrl":"10.1016/j.ijft.2025.101456","url":null,"abstract":"<div><div>This study presents a comprehensive analytical and numerical investigation of magnetohydrodynamic (MHD) viscoelastic fluid flow with heat and mass transfer in an asymmetric wavy channel. The primary objective is to explore the behavior of chemically reactive, thermally radiating non-Newtonian fluids under complex boundary conditions and oscillatory pressure gradients. A distinctive feature of this work lies in the formulation and solution of complex differential equations, which are decomposed into real and imaginary components to capture the full dynamics of the system. Three solution techniques—including one exact analytical and two semi-analytical methods—are employed, enabling a robust validation framework. The novelty of the study stems from the comparative analysis of semi-analytical methods against exact solutions, offering a unique benchmark for future modeling efforts. Parametric studies reveal that specific physical parameters selectively influence either the real or imaginary components of velocity, temperature, and concentration fields. These findings have direct relevance to engineering applications such as thermal management, biomedical flows, and porous media transport.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"30 ","pages":"Article 101456"},"PeriodicalIF":0.0,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145466087","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}

{"title":"Forced convection and exergy analysis of discrete metal foams filled in a channel","authors":"A G Thimmaiah ,&nbsp;Sadananda Megeri ,&nbsp;Banjara Kotresha ,&nbsp;M Muniraju ,&nbsp;T C Shubha ,&nbsp;Suresh Kote ,&nbsp;K P Jhansilakshmi ,&nbsp;Shashikumar C M","doi":"10.1016/j.ijft.2025.101455","DOIUrl":"10.1016/j.ijft.2025.101455","url":null,"abstract":"<div><div>The work presents the exergy analysis of discrete/baffle metal foam filled in an asymmetrical heated channel using 2^nd law of thermodynamics. The metal foam heat exchangers are deliberated as promising candidate for augmenting the heat transfer rate in numerous thermal applications, especially like electronics cooling, and etc. The objective of the analysis is to find the optimum discrete/baffle metal foam configuration that gives the superlative hydrothermal outcomes. Hence, the main aim of the investigation is to obtain the best suitable discrete/baffle metal foam combination among two, three, four and five discrete/baffles configurations positioned at various locations in the test section. For this purpose, the province taken up for the analysis comprises a horizontal channel in which an integrated heater cum aluminium plate assembly is positioned on the top wall. A constant heat input is assigned to the heater and the water coolant flowing through the channel takes away the heat generated inside the aluminium plate. The heat transfer through the channel is increased by using various discrete/baffle metal foam filling combinations. A combined DEF (Darcy Extended Forchheimer) along with LTE (Local Thermal Equilibrium) popular models are considered for envisaging the flow and heat transfer characteristics through the metal foam. The adopted procedure in the current work is initially authenticated using literature results. The upshots confirms that the discrete/baffle metal foam is best suited for enhancing the thermal properties compared to clear channel as well as fully filled metal foam channel. Among the various configuration studied the five discrete/baffle metal foam configuration gives the higher thermal improvement likened to other two, three and four metal foam configurations. The five discrete/baffle metal foam stretches approximately 74.27 % heat transfer likened with completely filled metal foam channel with nearly 50 % reduced pressure. It is evaluated from Colburn j factor that two, three, four and five discrete/baffle configuration gives an average of 167.04 %, 312.71 %, 315.54 % and 384.35 % increase in thermal performance respectively compared to clear channel. The working limits permitted by exergy (WLPE) is estimated based on exergy results for the selected configurations and found that the WLPE for 1-3 (two), 3-4-5 (three), 2-3-4-5 (four) and 1-2-3-4-5 (five) discrete/baffle metal foams configurations are 5024.96, 4182.93, 4169.14 and 3902.75 respectively. The exergy results also proves the selection of best optimum configuration.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"30 ","pages":"Article 101455"},"PeriodicalIF":0.0,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145363001","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}

{"title":"Thermo-hydraulic performance assessment of mono and hybrid ceramic nanofluids in flat plate solar collectors: a CFD-based study","authors":"Abdel Salam Alsabagh ,&nbsp;Ismail Masalha ,&nbsp;Omer A. Alawi ,&nbsp;Zaher Mundher Yaseen ,&nbsp;Ali Alahmer","doi":"10.1016/j.ijft.2025.101415","DOIUrl":"10.1016/j.ijft.2025.101415","url":null,"abstract":"<div><div>Ceramic nanoparticles have shown great potential in enhancing renewable energy systems and thermal management systems. This study investigates the thermo-hydraulic performance of mono and hybrid nanofluids synthesized by dispersing Titanium diboride (TiB₂), Boron carbide (B₄C), and a hybrid TiB₂: B₄C blend (20:80 weight ratio) into propylene glycol-water (PG: W, 20:80 wt.%) base fluid, with a fixed nanoparticle concentration of 2 wt.%. The thermophysical properties of the nanofluids were evaluated at three inlet temperatures: 298.15 K, 308.15 K, and 318.15 K. A three-dimensional numerical model was developed using ANSYS 2021R1 to simulate flow behavior over a Reynolds number range of 100–900. Key performance indicators included outlet and surface temperatures, heat transfer coefficient (h_tc), Nusselt number (Nu), pressure drop (ΔP), absorbed heat (Q_abs), and energy efficiency (η_eng). At 298.15 K, the TiB₂: B₄C hybrid nanofluid demonstrated a 4.38 % improvement in thermal conductivity over the base fluid (PG:W) and a 26.3 % reduction in viscosity compared to B₄C, demonstrating a balanced enhancement of thermal and flow properties. While B₄C exhibited the highest heat transfer coefficients (12–19 % above PG:W and 4.8–10.4 % higher than TiB₂:B₄C), its high viscosity resulted in increased pumping demands. In contrast, the hybrid nanofluid achieved energy efficiency up to 10 % higher than PG:W while remaining within 2–5 % of B₄C’s performance. With increasing temperature, all nanofluids exhibited a ∼78 % reduction in pumping power due to decreased viscosity, with TiB₂:B₄C consistently requiring the lowest pumping energy, up to 60 % less than B₄C. These results highlight the TiB₂:B₄C hybrid nanofluid as a thermally efficient and energy-saving alternative for practical heat transfer systems.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"30 ","pages":"Article 101415"},"PeriodicalIF":0.0,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145097957","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}

{"title":"Potential of physics-informed neural networks for analysing chemically reactive fluid flow past a deformable rotating cone due to generated and absorbed heat propagated by Arrhenius kinetics","authors":"Pudhari Srilatha ,&nbsp;Chandan K ,&nbsp;Talha Anwar ,&nbsp;R. Naveen Kumar ,&nbsp;Lal Sing Naik","doi":"10.1016/j.ijft.2025.101433","DOIUrl":"10.1016/j.ijft.2025.101433","url":null,"abstract":"<div><div>The investigation of thermofluid transport in deformable and rotating geometries is crucial in recent engineering fields, since these flows occur in heat management devices, catalytic reactors, energy storage systems, and innovative manufacturing processes. Motivated by these applications, the current study inspects the flow of a chemically reactive fluid induced by an extending or contracting rotating cone subjected to wall-deforming boundary conditions. Additionally, this model integrates the combined effects of endothermic and exothermic chemical reactions, magnetic field, porous medium, non-linear thermal radiation, and cross-diffusion phenomena to assess the fluid flow, heat, and mass transport features. Using the similarity variables, the partial differential equations are converted to ordinary differential equations. Furthermore, the reduced equations are solved numerically using the finite difference method. Moreover, a physics-informed neural network architecture is presented to enhance prediction accuracy by integrating fluid flow physics with artificial intelligence. The major findings of the present study show that the velocity profiles get more intense as the ratio of deformation to rotation parameter values increases. The thermal profile increases for the exothermic case and decreases for the endothermic case as the values of the chemical reaction parameter increase. As the radiation parameter values increase, the Nusselt number decreases by approximately 15.7 %. The Nusselt number decreases by around 42.3 % in the exothermic case and increases by around 24.1 % in the endothermic case when the chemical reaction parameter increases. These results offer both methodological innovation and valuable insights with applications in energy-efficient flow systems, porous media transport, and chemical processing.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"30 ","pages":"Article 101433"},"PeriodicalIF":0.0,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145269095","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}

{"title":"Study of the cascade system model for waste heat recovery from the flue gases of the electric arc furnace","authors":"К. Volchanska ,&nbsp;A. Yerofieieva ,&nbsp;О. Barishenko ,&nbsp;A. Vlasov ,&nbsp;М. Ivchenko ,&nbsp;А. Yeremenko","doi":"10.1016/j.ijft.2025.101437","DOIUrl":"10.1016/j.ijft.2025.101437","url":null,"abstract":"<div><div>The paper deals with methods for recovering a significant part of the thermal energy consumed by the metallurgical industry and discarded as waste heat from the electric arc furnace. One of the main sources of heat removal from an electric arc furnace is the emissions of high-temperature waste gases. The use of waste heat recovery methods allows the energy efficiency of the technological process to be increased, operating costs for steel production to be reduced, and also hazardous emissions into the environment to be reduced. The study was conducted in an ultra-high-power electric arc furnace along with preheating of steel scrap in a closed container using residual heat from flue gases. The temperature of the flue gases and the flow velocity profiles of the electric arc furnace were obtained experimentally and used as the basis for developing the cascade system model for the waste heat recovery from the flue gases. The novelty of this study is in the development and modeling of a combined cascade system for waste heat recovery from the flue gases of a powerful electric arc furnace (EAF), which includes three daisy-chained energy subsystems: a steam Rankine cycle (RC), an organic Rankine cycle (ORC) and a heat pump (HP) system. The proposed multi-stage structure of the system provides a step-by-step decrease in the temperature of flue gases and an effective heat transfer to several independent energy flows. This ensures the increased flexibility of the system, reduced energy losses and adaptability to the cyclic operation mode of the furnace. In this study, exergy analysis was used for the first time to set the tasks in the form of variational inequalities, reflecting the distinct dissipative properties of materials associated with energy losses. Usage of variational inequalities allowed us to build a mathematical model that adequately describes the recovery process, taking into account losses and limitations. The simulation results showed a reduction in electricity consumption by 40–50 kWh/t (saving approximately 8–12 %), a reduction in melting time by 5–8 min (reduction by 10–15 %), and a reduction in electrode consumption by 0.2–0.4 kg/t (saving approximately 7–12 %). The heat efficiency of the electric arc furnace increased by 70 %. Experimental studies confirmed the adequacy of the proposed strategies and calculations.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"30 ","pages":"Article 101437"},"PeriodicalIF":0.0,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145269110","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}

{"title":"Using computational fluid dynamics to explore new hydrokinetic fluid coupling design for industrial applications","authors":"Deep Prajapati ,&nbsp;Hasmukh G. Katariya ,&nbsp;Vipul H. Chaudhari ,&nbsp;Lalit Nakrani ,&nbsp;Amit Prajapati ,&nbsp;Pranav Mehta ,&nbsp;Ravishankar Sathyamurthy","doi":"10.1016/j.ijft.2025.101471","DOIUrl":"10.1016/j.ijft.2025.101471","url":null,"abstract":"<div><div>This study presents the initial design and computational investigation of a traction-type hydrokinetic fluid coupling for industrial applications. The problem addressed is the limited availability of validated mathematical and computational models for optimizing impeller–runner design and oil selection in fluid couplings. The objective is to establish an empirical–computational framework that combines dimensional analysis with CFD simulations to accurately predict operating behavior. The impeller and runner were designed using dimensional analysis–based empirical relations, supported by assumptions of incompressible flow, constant density, and steady-state operating conditions with a slip of 2–3 %. The theoretical oil mass required for power transmission was calculated using Rolfe’s hydrodynamic equations, and validated against actual industry data. For a 420-size coupling operating at 1500 rpm impeller speed and 1450 rpm runner speed, the predicted oil requirement was 9.33 L versus the actual 10.05 L. CFD analysis employing a moving mesh and k–ω turbulence model revealed a maximum dynamic pressure of 5.4 bar and tangential velocity of 34 m/s, which produced a torque of 507.3 Nm and transmitted power of 79.9 kW, matching the rated 80 kW within 0.13 %. These results confirm that the proposed empirical–CFD framework accurately captures pressure distribution, vortex dynamics, and slip characteristics, thereby validating the mathematical assumptions. The study establishes a robust base for optimizing hydrokinetic couplings to achieve 95–98 % efficiency with reduced slip, and provides insights for future improvements in rib geometry, oil filling strategies, and material selection</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"30 ","pages":"Article 101471"},"PeriodicalIF":0.0,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145466085","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}

{"title":"Analyzing heat and mass transfer of nanofluid flow on a stenosed artery applying endo-exothermic chemical reaction and bioconvection using a model-agnostic meta-learner technique: A numerical approach","authors":"Shivalila Hangaragi ,&nbsp;Neelima N ,&nbsp;G K Tejaswini ,&nbsp;K Vinutha ,&nbsp;Amal Abdulrahman ,&nbsp;J K Madhukesh","doi":"10.1016/j.ijft.2025.101470","DOIUrl":"10.1016/j.ijft.2025.101470","url":null,"abstract":"<div><div>In fluid flow applications, endothermic and exothermic chemical reactions are important, especially in the scientific and engineering fields. They make advanced modeling and optimization of complex systems possible when combined with artificial neural networks (ANNs). As a result, the present investigation uses ANNs to study the influences of heat source/sink, endothermic/exothermic chemical reactions, and Darcy-Forchheimer porous media on the two-dimensional, stable, incompressible flow of bio-convection nanofluids through a stenosed artery (cylinder). Using appropriate similarity equations, non-linear partial differential equations are transformed into ordinary differential equations, which are then resolved with RKF-45 and the shooting technique. Important engineering coefficients were also investigated. Outcomes show that in an endothermic chemical reaction, the temperature profile increases as the chemical reaction parameter rises, whereas in an exothermic chemical reaction, the reverse behaviour is observed. The <span><math><mrow><mi>C</mi><mi>f</mi><mo>%</mo></mrow></math></span>shows negligible variations with the addition of nanoparticles at about 8.2 % across distinct parameter values. The <span><math><mrow><mi>N</mi><mi>u</mi><mo>%</mo></mrow></math></span>is strongly influenced by nanoparticles, increasing significantly for <span><math><mrow><msub><mi>λ</mi><mn>1</mn></msub><mo>&gt;</mo><mn>0</mn></mrow></math></span> than <span><math><mrow><msub><mi>λ</mi><mn>1</mn></msub><mo>&lt;</mo><mn>0</mn></mrow></math></span>. Model-Agnostic-Meta-Learning relative studies show high convergence; it generalizes effectively on unknown data. Error histogram studies validate performance analysis, training is stable, and the predicted values almost equal the actual values, proving its effectiveness.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"30 ","pages":"Article 101470"},"PeriodicalIF":0.0,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145466704","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}

{"title":"Viscous fluid flow past a permeable sphere- ANN approach","authors":"P. Aparna ,&nbsp;V.Ganesh Kumar ,&nbsp;P. Padmaja ,&nbsp;H. Niranjan","doi":"10.1016/j.ijft.2025.101475","DOIUrl":"10.1016/j.ijft.2025.101475","url":null,"abstract":"<div><div>The current paper explores artificial neural networks (ANNs) approach to analyze flow of a viscous fluid through a spongy sphere. The aim of this study is to analyze viscous fluid flow past axisymmetric permeable sphere using Artificial Neural Networks (ANN). The specific objectives are to investigate velocity and pressure distributions. The proposed approach integrates Analytical methods with ANN modeling to achieve accurate predictions and deeper physical insight into viscous fluid flow behavior. The flow is regulated by non-linear PDE’s in terms of the stream function, subject to the relevant frontier conditions. The stream function is used to describe the flow pattern of the sphere's interior and exterior. The permeability parameter's limits are evaluated. The streamlining design is illustrated for various kinds of permeability parameter values. We investigate numerically how the permeability parameter affects drag, and findings are illustrated through graphs. The Feed-Forward Neural Network (FFNN) methods are employed to generate and study the solution for regulated fluid flow. A multilayer perceptron (MLP) neural network is employed in the sample functions. The adaptive moment estimation (ADAM) algorithm is employed to compute the adjustable parameters. The mathematical computations of both ANN and exact solutions are presented in tabular form and visually displayed for various physical parameter values. The effectiveness of the solution improves with the expansion of neurons and data points in neural networks. R-Squared values of 0.999 were achieved for the stream function of the fluid. Moreover, because to its diminished time and processing capacity demands for problem-solving, the current ANN framework can be used to more intricate models.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"30 ","pages":"Article 101475"},"PeriodicalIF":0.0,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145568795","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}

{"title":"Ternary hybrid-nanofluid magneto-convective flow inside the octagonal enclosure with an inner circular obstacle contribution to entropy generation","authors":"Nur Jahangir Moon ,&nbsp;Bijan Krishna Saha ,&nbsp;Jahidul Islam Jihan ,&nbsp;Goutam Saha ,&nbsp;Md.Nur Alam ,&nbsp;Suvash.C. Saha","doi":"10.1016/j.ijft.2025.101480","DOIUrl":"10.1016/j.ijft.2025.101480","url":null,"abstract":"<div><div>Natural convection (NC) plays a pivotal role in convective heat transfer (HT) and has been extensively studied. This research focuses on examining the impact of different parameters on HT and fluid flow behavior of a ternary hybrid nanofluid (Al₂O₃-Fe₃O₄_<img>Cu-H₂O) under the influence of a magnetic field within an octagonal enclosure containing a circular obstacle. This work investigates HT features of a buoyancy-driven NC flow that is laminar, steady and incompressible. The study also takes into account the entropy generation (E_gen) and the Bejan number (Be) in an octagonal enclosure with an inner circular obstacle for varying boundary conditions. The finite element method is used to numerically solve the governing equations and the associated boundary conditions. A variety of parameter values are employed in this study such as 0 % ≤ nanoparticles volume fraction (φ) ≤ 5 %, 10³ ≤ Rayleigh number (Ra) ≤ 10⁶, 0 ≤ Hartmann number (Ha) ≤ 60. The present analysis highlights that the rate of HT and E_gen can be improved by adding ternary hybrid nanoparticles within the cavity by 42.9 % and 14.89 % respectively. However, the average E_gen becomes higher for increasing Ra and decreasing Ha at φ_a = φ_b = φ_c = 5 %. Moreover, larger nanoparticle volumes result in improved thermal performance, especially when Ra is higher. The ternary hybrid nanofluids for this architecture has the potential to improve thermal management systems by efficiently reducing external heat loss.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"30 ","pages":"Article 101480"},"PeriodicalIF":0.0,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145568794","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}