International Journal of Thermofluids最新文献

{"title":"Chest freezer with integrated heat exchanger for augmenting the COP","authors":"K. Srithar ,&nbsp;R. Venkatesan ,&nbsp;S.Abishai Immanuel ,&nbsp;M. Krishkarna ,&nbsp;R. Saravanan","doi":"10.1016/j.ijft.2025.101157","DOIUrl":"10.1016/j.ijft.2025.101157","url":null,"abstract":"<div><div>The study analyzes the performances of a modified chest freezer with a heat exchanger. The experiments are performed on the chest freezer to analyze the impact of baffles of various geometries placed inside the heat exchanger on the freezer's coefficient of performance. To remove the thermal energy the refrigerant before condensation phase, water is used as a coolant in the heat exchanger. Baffles with four different profiles were used for the analyses and they were baffles with sextant geometry, sextant profile with holes, strip cuts, and internal sextant cuts. Experiments are performed with various water mass flow rates and for different product loads. Further experiments are conducted for to analyze the performance of chest freezer for increase in number of baffles inside the heat exchanger. Experimental results indicate that the segmental baffles having sextant profiles with internal sextant cuts showed the best performance in terms of COP and low irreversibility. The coefficient of performance increased from 0.9 to 0.1 when conventional VCR systems were integrated with heat exchangers having six numbers of inserts and keeping the mass flow rate at 0.43 kg/s. The proposed VCR saw a reduction of 10 % consumes in power consumption compared to conventional VCR.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"27 ","pages":"Article 101157"},"PeriodicalIF":0.0,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143601043","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Techno-economic, social and environmental analysis of different photovoltaic cell technologies under tropical weather conditions","authors":"Ephraim Bonah Agyekum ,&nbsp;Flavio Odoi-Yorke ,&nbsp;Agnes Abeley Abbey ,&nbsp;Oluwatayomi Rereloluwa Adegboye ,&nbsp;Farhan Lafta Rashid","doi":"10.1016/j.ijft.2025.101164","DOIUrl":"10.1016/j.ijft.2025.101164","url":null,"abstract":"<div><div>Despite Nigeria's enormous energy resources, it has the largest number of people without access to electricity in the world. This is partly due to the lack of diversification of its sources of energy generation, leaving a large number of its population in darkness. This study thus employed the System Advisor Model developed by the National Renewable Energy Laboratory to estimate the technical and economic performance of a 100 MW solar PV power plant at Kaduna in Nigeria, considering six different PV cells, i.e., c-Si, mc-Si, 3-a-Si, a-Si/mono-Si, CIS, and HIT-Si. The potential hydrogen, ammonia, land requirement, jobs that could be created, and the environmental impact of installing the PV systems were also assessed. From the results, the 3-a-Si PV system achieved the lowest real LCOE (2.88 cent/kWh) and highest NPV ($30,545,648) due to its high energy yield. The study revealed that the annual hydrogen production from PV cells, using different scenarios of 10 %, 15 %, 20 %, and 25 % of the electricity generated, varies between 311 and 348 metric tons, 467–522 metric tons, 622–696 metric tons, and 778–871 metric tons, respectively. The estimated LCOH for hydrogen production from a 100 % PV power plant electricity can range from $1.83/kg to $2.05/kg across various PV technologies analyzed. The project's economic viability depends on module cost. Nigerian and West African governments can reduce initial PV unit costs by implementing policies, incentives, and tax cuts.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"27 ","pages":"Article 101164"},"PeriodicalIF":0.0,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143621373","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A review of carbon and aluminium nanofluids and elastocaloric materials for heating and cooling applications","authors":"Anesu Nyabadza ,&nbsp;Éanna McCarthy ,&nbsp;Mayur Makhesana ,&nbsp;Saeid Heidarinassab ,&nbsp;Lola Azoulay-Younes ,&nbsp;Kevin O'Toole ,&nbsp;Mercedes Vazquez ,&nbsp;Dermot Brabazon","doi":"10.1016/j.ijft.2025.101163","DOIUrl":"10.1016/j.ijft.2025.101163","url":null,"abstract":"<div><div>Nanofluids, suspensions of nanoparticles (NPs) in base fluids, enhance heat transfer in heating and cooling applications. Carbon and aluminium based nanofluids are the most promising materials owing to high stability, excellent thermal properties, low cost and high sustainability. This review critically examines the use of aluminium and carbon-based nanofluids, focusing on their synthesis, stability, thermal properties, and practical applications. Incorporating Al₂O₃, AlN, graphene, or C NPs into base fluids like water, methanol and ethylene glycol significantly enhances thermal conductivity and heat transfer performance. Carbon-based NPs added to water can result in up to 5000 W/m.K in thermal conductivity from 0.607 W/m.K. The two main synthesis methods namely one-step and two-step processes are discussed. The review also addresses challenges such as sedimentation, agglomeration, and channel blockage, providing insights into strategies for enhancing nanofluid stability and performance. Another limiting factor is the increased viscosity with increasing NP loading, with studies reporting up to a 138 % rise in fluid viscosity, which substantially raises the pumping power required. Future prospects such as using elastocaloric Ni-Ti alloys together with nanofluids for enhanced and sustainable heat transfer are reviewed.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"27 ","pages":"Article 101163"},"PeriodicalIF":0.0,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143562688","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Natural convection of water/Titanium oxide nanofluid inside a closed enclosure at different angles of attack","authors":"Laith S. Sabri ,&nbsp;Ali B.M. Ali ,&nbsp;Omid Ali Akbari ,&nbsp;Farnaz Montazerifar ,&nbsp;Faramarz Kahbandeh ,&nbsp;Soheil Salahshour ,&nbsp;A. Mokhtarian","doi":"10.1016/j.ijft.2025.101161","DOIUrl":"10.1016/j.ijft.2025.101161","url":null,"abstract":"<div><div>In most industrial applications, several situations are associated with closed enclosures, such as avionics, automotive, cooling/heating systems in buildings, electronic equipment, food, and phase change materials. In this paper, the natural convection (NC) of a Newtonian fluid inside a Non-Square Closed Enclosure (NSCE) is numerically simulated. The working fluid is a water/Titanium oxide nanofluid (NF) with volume fractions in the range of φ = 0 to 4 % and experiences a laminar flow with Rayleigh numbers (Ra) from 10³ to 10⁵. To benefit from better flow mixing, NSCE undergoes five different angles of attack -90°, -45°, 0°, 45°, and 90° degrees (cases 1 to 5, respectively). This research was solved using a computer code in two-dimensional space in steady state using the finite volume method. The solid-fluid suspension is considered homogeneous, single-phased, and Newtonian. The Boussinesq approximation is used for the density term. A SIMPLE algorithm is used for decoupling pressure and velocity fields. The results suggest that increasing the Ra number strengthens the fluid velocity components in the Closed Enclosure (CE). In all cases, the maximum Nusselt number (Nu) occurs at the interface between the fluid and the hot surface. In cases (1) and (5), due to the elongation of the fluid path, the circulation effects become more important, creating an anomaly in the friction factor for the <em>Ra</em> = 10⁵. A symmetric pattern in the Nu number diagrams in cases (2) and (4) is evident which is due to the invariance of this parameter in these two cases. Entropy generation is influenced by fluid circulation and rotation. In all cases and conditions, the use of solid nanoparticles reduces the temperature gradient, which significantly affects the removal of hot spots with high entropy and consequently reduces the average entropy generation. Increasing the angle of attack of the closed enclosure compared to the smooth case (case 3) at Rayleigh numbers 10³ and 10⁴ can increase the friction coefficient by a factor of 1.62. Also, at Rayleigh number 104, changes in the angle of attack of the closed enclosure will experience a decrease in the Nusselt number and average heat flux by &lt;8 % compared to the smooth case. At Rayleigh number 10³, the 10 % increase in the average Nusselt number and heat flux is only due to the increase in the volume fraction of the solid nanoparticle and is somewhat independent of the angle of attack of the closed enclosure.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"27 ","pages":"Article 101161"},"PeriodicalIF":0.0,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143680357","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of hall current and rotational on MHD flow of nanofluid with joule heating and viscous dissipation","authors":"Guthula Kanaka Lakshmi,&nbsp;Paramsetti Sri Ramachandra Murty","doi":"10.1016/j.ijft.2025.101153","DOIUrl":"10.1016/j.ijft.2025.101153","url":null,"abstract":"<div><div>This study investigates the influence of Hall current, rotational effects, and thermal diffusion on the transient magnetohydrodynamic (MHD) free convection flow of water-based Cu and TiO₂ nanofluids, incorporating the effects of Joule heating and viscous dissipation. The fluid motion occurs along a permeable vertical plate under an applied magnetic field in a rotating frame of reference. The governing equations, formulated as partial differential equations (PDEs), are transformed into a system of ordinary differential equations (ODEs) using non-dimensionalization techniques and are solved analytically via the perturbation method. The study presents an in-depth analysis of velocity and temperature distributions, as well as the effects of key parameters such as the hall current, rotational force, thermal radiation and suction parameter. Results indicate that an increase in the Hall parameter enhances the velocity of the primary flow but decreases secondary velocity. The velocity profile also increases with higher thermal Grashof number, while a rise in the magnetic field strength retards fluid motion due to Lorentz force effects. The temperature profile decreases with increasing Prandtl number and heat source intensity. These findings provide valuable insights into the behavior of nanofluid flow in MHD environments and have potential applications in energy systems, cooling technologies, and electronic thermal management.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"27 ","pages":"Article 101153"},"PeriodicalIF":0.0,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143609329","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigating the combinations of operating parameters of PEMFC computational results using the Taguchi Method","authors":"Prem Kumar Thiyagarajan ,&nbsp;Nithesh Kumble Gokuldas ,&nbsp;Srinivasa G ,&nbsp;Avinash Kumar Rajendran ,&nbsp;Kavin Selvan Saravanakumar ,&nbsp;Mohanaharish Vasudevan ,&nbsp;Mohith Kannan ,&nbsp;C. Durga Prasad ,&nbsp;Adem Abdirkadir Aden","doi":"10.1016/j.ijft.2025.101162","DOIUrl":"10.1016/j.ijft.2025.101162","url":null,"abstract":"<div><div>Proton Exchange Membrane Fuel Cells (PEMFC) is considered a promising energy source due to higher energy efficiency, low pollution, fast startup time, and low operating temperature. Under simplified conditions of constant temperature and one-dimensional flow, through the channel, and zero-flux boundaries the model was solved. The model was validated using COMSOL Multiphysics software and experimental results with a 4.22 % and 5.5 % deviation. The Taguchi Method was used to study the operating parameters of PEMFCs and to identify optimal combinations for best output along with developing equations to predict maximum power density. The delta i.e. the difference between the mean of high- and low-level Signal to Noise (S/N) ratios was calculated and found that the relative humidity was significant with value 11.07. The optimum combination is found with the help of the S/N ratio graph based on the larger the better for the performance application. The maximum power density value was predicted using the equation and found to be deviated by 16.5 % with the help of an L8 orthogonal array. Modified Taguchi approach with L4 orthogonal array with a fixed level of higher derivation parameter, reduced the error deviation further to 6.5 % with respect to the simulation results. The approach will be handy for predicting the performance with fewer trials.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"27 ","pages":"Article 101162"},"PeriodicalIF":0.0,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143576853","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis and prediction of thermo-physical properties in water-based MWCNT-ZnO hybrid nanofluids using ANN and ANFIS models","authors":"Surendra D. Barewar ,&nbsp;Pritam S. Kalos ,&nbsp;Balaji Bakthavatchalam ,&nbsp;Mahesh Joshi ,&nbsp;Sarika Patil ,&nbsp;Mahesh Sonekar","doi":"10.1016/j.ijft.2025.101159","DOIUrl":"10.1016/j.ijft.2025.101159","url":null,"abstract":"<div><div>In this study, the thermal conductivity and viscosity of multiwalled-carbon nanotubes/zinc oxide water hybrid nanofluid across volume concentrations varying from 0.2 % to 0.8 % and temperatures from 25 °C to 65 °C were experimentally studied. Three mathematical models such as multivariable regression, artificial neural network, and adaptive neuro-fuzzy modeling were employed for the prediction of the thermal conductivity of the water baes multiwalled-carbon nanotubes/zinc oxide hybrid nanofluid. Volume concentration and temperature of the nanofluid are the input parameters for the models. Despite the complexity of the input data, which encompassed extensive ranges of temperature and volume concentration, adaptive neuro-fuzzy modeling exhibited superior predictive performance than the other two models. It achieved conductivity values closely aligned with experimental results, characterized by the lowest mean square error compared to regression and artificial neural network models. Notably, the adaptive neuro-fuzzy modeling method facilitated the resolution of the neural network layer's hidden structure without the need for extensive trial and error.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"27 ","pages":"Article 101159"},"PeriodicalIF":0.0,"publicationDate":"2025-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143576854","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"AI-heat transfer analysis of casson fluid in uniformly heated enclosure with semi heated baffle","authors":"Khalil Ur Rehman ,&nbsp;Wasfi Shatanawi ,&nbsp;Lok Yian Yian","doi":"10.1016/j.ijft.2025.101148","DOIUrl":"10.1016/j.ijft.2025.101148","url":null,"abstract":"<div><div>The heat transfer in Casson fluid with natural convection claims various applications namely thermal regulation in biological systems, solar collectors, polymer processing, and geothermal applications to mention just a few. Owing to such motivation, we have offered artificial intelligence-based solution outcomes for heat transfer aspects in Casson fluid flow in a partially heated square enclosure with free convection effect. The semi-heated triangular baffle is installed at the center of the cavity. The bottom and right walls have the same amount of heat. The left wall of the cavity is taken cold and the top wall is taken insulated. The surface of triangular baffle and cavity walls are carried with non-slip condition. Finite element method (FEM) with hybrid meshing is used to solve the developed flow equations. AI-based neural networks model is used to examine the variation in Nusselt number for the involved flow parameters. MSE=2.15008e^-6, 5.81476e^-5, and 3.51888e^-4 for training, validation, and testing respectively, suggesting good model performance on Nusselt number data along the bottom and vertical walls. We have observed that the heat transfer coefficient improves as Rayleigh and Prandtl numbers increase. We believe that the present AI-based outcomes will be helpful for predicting natural convection phenomena subject to thermal engineering standpoints.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"26 ","pages":"Article 101148"},"PeriodicalIF":0.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143509099","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bioconvective triple diffusion flow of micropolar nanofluid with suction effects and convective boundary conditions","authors":"Muhammad Bilal Riaz ,&nbsp;Kamel Al-Khaled ,&nbsp;Adnan ,&nbsp;Sami Ullah Khan ,&nbsp;Katta Ramesh","doi":"10.1016/j.ijft.2025.101138","DOIUrl":"10.1016/j.ijft.2025.101138","url":null,"abstract":"<div><div>This investigation reveals the triple diffusive bioconvective applications subject to micropolar nanofluid flow caused by oscillating stretched surface. The problem is subject to applications of radiative phenomenon and viscous dissipation features. In oscillating stretching surface, the porous medium and suction/injection features are considered. The modeling of flow problem is based on system of partial differential equations (PDE's). Such system is solved with implementation of homotopy analysis method (HAM). The convergence region is specified against HAM solution. Understanding of flow problem is observed by vary various flow parameters to evaluates the fluid velocity, micro-rotational velocity, temperature field, solutal concentration, nanoparticles concentration and microorganisms profile. The results for skin friction, Nusselt number, solutal Sherwood number, nano-Sherwood number and microorganism's density number are also presented. It has been observed that variation of velocity against time periodically oscillates and magnitude of oscillation declined due to porous parameter and suction/injection constant. The temperature profile enhances due to modified Dufour number and Eckert parameter. Moreover, the solutal concentration reduces due to regular Lewis number.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"26 ","pages":"Article 101138"},"PeriodicalIF":0.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143561800","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Soret and nonuniform heat source/sink effects in micropolar nanofluid flow over an inclined stretching sheet","authors":"Machindranath Diwate ,&nbsp;Pradeep G. Janthe ,&nbsp;Nitiraj V. Kulkarni ,&nbsp;S. Sunitha ,&nbsp;Jagadish V. Tawade ,&nbsp;Nodira Nazarova ,&nbsp;Manish Gupta ,&nbsp;Nadia Batool","doi":"10.1016/j.ijft.2025.101160","DOIUrl":"10.1016/j.ijft.2025.101160","url":null,"abstract":"<div><div>This study investigates the heat and mass transfer dynamics of micropolar nanofluid flow over a stretching sheet subjected to nonuniform heat sources/sinks. The influence of key factors, such as Brownian motion, thermophoresis, chemical reactions, and thermal radiation, on the velocity, temperature, and concentration profiles of the nanofluid is explored. The research employs advanced numerical methods, using the <em>bvp4c</em> solver, to solve the governing equations and compute the effects of various physical parameters on fluid dynamics. The results demonstrate that an increase in the magnetic field strength reduces the fluid velocity, while changes in material properties can lead to higher fluid speeds. Furthermore, the Soret effect significantly enhances mass transfer and the heat transfer at the surface diminishes as <em>A*</em> and <em>B*</em> increases, with implications for applications in separation technologies and desalination. A detailed analysis of the influence of the Soret number, Brownian motion, and thermophoresis reveals critical insights into thermal transport and solute distribution in the boundary layer. These findings have practical applications in cooling systems, biomedical engineering, and other industries where precise control of heat and mass transfer is crucial.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"27 ","pages":"Article 101160"},"PeriodicalIF":0.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143636686","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}