Heat Transfer最新文献

{"title":"Optimization of Heat Transfer on Carbon Nanotubes With Exponential Heat Generation and Nonlinear Radiation in Sakiadis and Blasius Flows Over Curved Surface","authors":"K. R. Roopa,&nbsp;M. V. Govindaraju,&nbsp;P. A. Dinesh,&nbsp;Sweeti Yadav","doi":"10.1002/htj.23275","DOIUrl":"https://doi.org/10.1002/htj.23275","url":null,"abstract":"<div>\u0000 \u0000 <p>Engineers and researchers in the field of thermal analysis are searching for novel approaches to boost their performance by enhancing the thermal characteristics of electrical equipment. Non-Newtonian fluids are used in technical and industrial settings owing to their high thermal conductivity. In connection with this, the present study investigates the fluid flow and heat transmission of a hybrid nanomaterial (carbon nanotubes and ferric oxide) over a curved surface. The originality of this study is related to examining the impact of heat generation and nonlinear thermal radiation with convective boundary conditions for Sakiadis flow (SF) and Blasius flow (BF). The system of mathematical relations in the partial differential equation form is changed to an ordinary differential equation (ODE) system using appropriate variables. The indeterminate ODEs were solved using the ODE analyzer, which is accessible in the computer software Maple. The graphs demonstrate the importance of the critical factors concerning the velocity and temperature fields. SF has a thinner boundary layer than BF, which results in a more pronounced temperature drop. The effects of altering the physical parameters on the Nusselt number were optimized through response surface methodology for BF and SF. SF is more affected by radiation effects, but BF shows increased sensitivity to wall temperature gradients, indicating distinct optimization approaches for each scenario. In every situation, the hybrid nanofluid of multiwall carbon nanotubes and ferric oxide exhibits excellent thermal performance. To validate the chosen numerical approach, a tabular description is provided to generate an excellent comparison.</p></div>","PeriodicalId":44939,"journal":{"name":"Heat Transfer","volume":"54 3","pages":"2093-2109"},"PeriodicalIF":2.8,"publicationDate":"2025-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143801768","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":"Reducing Air-Conditioning Load by Using an Insulating Material in Iraq as a Case Study (Experimental and Numerical)","authors":"Atif Ali Hasan,&nbsp;Omer Adil Zainal Al-Bayati,&nbsp;Noor Samir Lafta,&nbsp;Mahmood H. Khaleel","doi":"10.1002/htj.23211","DOIUrl":"https://doi.org/10.1002/htj.23211","url":null,"abstract":"<div>\u0000 \u0000 <p>This paper has studied different types of walls using constant interior and exterior finishing materials (thermostone, 200-mm thick (A); fired clay bricks, 240-mm thick (B); hollow concrete blocks, 200-mm thick (C); solid concrete blocks, 140-mm thick (D); and limestone, 200-mm thick (E)) due to the availability of many different types of building materials in Iraq and the lack of control over the best use to demonstrate how each of these materials affects a building's insulation to deliver the appropriate levels of comfort and achieve the greatest possible reduction in the electrical energy needed for air conditioning. A unique chamber was created for performing the actual trials on such walls in their natural environment, which was the climate of the city of Baghdad (zip code 10016, 33° N latitude, 44° E longitude). The tests have been done both in their current state of operation and with the addition of thermal insulation (60-mm thick microfiber glass insulation material). The values for electricity consumption by a wall without insulation are 92, 121, 199, 148, and 138 kW/m², in cases noted as A1, B1, C1, D1, and E1, respectively. However, when the insulator is used, the values become 58, 63, 51, 100, and 92 kW/m² for the cases noted as A2, B2, C2, D2, and E2, respectively. The percentage reduction in electrical energy consumed by the air conditioner used within the room with and without thermal insulation has been recorded in the range of 50%–65% and 25%–60%, respectively. Depending on the model used, and compared with the traditional model, the saving difference with and without insulation was 15% and 35%, respectively. The best case is C2, because it has no effect on the room's interior area. Also, the cooling load was less than in other cases; it was 51 kW/m² and had the highest building electrical savings, which are 65% when taking the wall in case C1 as a reference.</p>\u0000 </div>","PeriodicalId":44939,"journal":{"name":"Heat Transfer","volume":"54 3","pages":"2049-2062"},"PeriodicalIF":2.8,"publicationDate":"2025-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143801765","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":"Analysis of Entropy Generation Within Coaxial Cylinder on MHD Free Convective Flow Due to Nonlinear Thermal Radiation in an Isothermal/Isoflux Condition","authors":"Isah Bala Yabo,&nbsp;Abubakar Zainab Dogondaji,&nbsp;Usman Halima,&nbsp;Mamuda Muhammad","doi":"10.1002/htj.23269","DOIUrl":"https://doi.org/10.1002/htj.23269","url":null,"abstract":"<div>\u0000 \u0000 <p>This study delves into entropy generation analysis within a coaxial cylinder containing an electrically viscous conducting fluid. Both cylinders have porous exteriors and are subjected to heat, with the outer cylinder being cooled. A combination of radial transverse magnetic field and velocity slip is applied. The analysis utilizes the thermal Rosseland diffusion approximation to describe radiative heat flux. The objective is to scrutinize entropy generation and the impact of isothermal and isoflux conditions on heat transfer due to nonlinear thermal radiation in a vertical coaxial cylinder. Steady and unsteady-state solutions are obtained through regular perturbation and implicit finite difference methods, respectively. The results indicate that the Suction parameter reduces fluid velocity, temperature, and skin friction in both the isothermal and isoflux conditions. Magnetic parameters reduce velocity, while Grashop number, injection, and radiation parameters increase velocity and entropy, especially under isothermal conditions. Overall, the results align well with existing literature.</p>\u0000 </div>","PeriodicalId":44939,"journal":{"name":"Heat Transfer","volume":"54 3","pages":"2063-2078"},"PeriodicalIF":2.8,"publicationDate":"2025-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143801766","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":"Numerical Analysis of Heat Transfer in Simultaneously Developing Laminar Flow in a Plane Duct With Constant Wall Temperature and Heat Flux Boundary Conditions","authors":"Ali Belhocine,&nbsp;Mohammed Sid Ahmed Houari,&nbsp;Nadica Stojanovic,&nbsp;Oday Ibraheem Abdullah","doi":"10.1002/htj.23274","DOIUrl":"https://doi.org/10.1002/htj.23274","url":null,"abstract":"<div>\u0000 \u0000 <p>The present study concerns, from the angle of numerical simulation, a laminar flow in a plane duct with simultaneously developing velocity and temperature profiles. It is assumed that the fluid is Newtonian, viscous, and incompressible, with uniform and constant physical properties. The problem of laminar flow heat transfer is analyzed for both constant wall temperature and uniform wall heat flux boundary conditions. The basic equations governing the flow, including continuity, momentum, and energy, are solved numerically. Dimensionless variables are introduced to simplify the proposed procedure, and an explicit finite-difference method is used to discretize the equations. The resulting computational method allows for the prediction of thermal behavior on an isothermal surface and under constant flux of certain parameters, such as velocity, temperature, and the Nusselt number. These results are presented graphically and discussed, highlighting the effect of certain variables on the outcome. Finally, a comparison is made with previous work, demonstrating good agreement.</p>\u0000 </div>","PeriodicalId":44939,"journal":{"name":"Heat Transfer","volume":"54 3","pages":"2079-2092"},"PeriodicalIF":2.8,"publicationDate":"2025-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143801767","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":"Impact of Variable Viscosity on Unsteady Couette Flow","authors":"Basant Kumar Jha,&nbsp;Yahaya Jibrin Danjuma","doi":"10.1002/htj.23263","DOIUrl":"https://doi.org/10.1002/htj.23263","url":null,"abstract":"<div>\u0000 \u0000 <p>This research presents the effect of space-dependent and viscosity variation on the time-dependent flow of viscous, incompressible fluid in a finite channel (Couette flow). The viscosity of the fluids is assumed to grow exponentially. The governing equations and the boundary conditions are nondimensionalized with the aid of dimensionless parameters and solved semi-analytically using the Laplace transformation method and its numerical inversion approach called Riemann-sum approximation (RSA). Time-dependent velocity profiles, time-dependent skin frictions, and time-dependent mass flow rates of the fluids with variables viscosity and of the fluids with constant viscosity are obtained exactly in the Laplace domain in terms of modified Bessel functions of the first and second kinds. Due to the complexity of the solutions to the problem, the analytical procedure could not be obtained in the time domain, so the RSA is sought. For the validation of the method used, steady-state solutions of the velocity profiles, skin frictions, and the mass flow rates of the fluids with variable viscosity and constant viscosity are obtained analytically and compared with the numerical results. Graphs are plotted and tables are tabulated for the analysis of the effect of space-dependent and viscosity variation of the fluid flows. In the course of analysis, it is observed that the velocity profile is higher in the case where the fluid viscosity is constant compared with the variable viscosity.</p>\u0000 </div>","PeriodicalId":44939,"journal":{"name":"Heat Transfer","volume":"54 3","pages":"2032-2048"},"PeriodicalIF":2.8,"publicationDate":"2025-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143801684","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":"Analysis of MHD Flow With Convective Boundary Conditions Over a Permeable Stretching Surface Using a Physics-Informed Neural Network","authors":"Bhaskar Jyoti Dutta,&nbsp;Bhaskar Kalita,&nbsp;Gautam K. Saharia","doi":"10.1002/htj.23268","DOIUrl":"https://doi.org/10.1002/htj.23268","url":null,"abstract":"<div>\u0000 \u0000 <p>In this study, we examine the impact of heat and mass transfer of magnetohydrodynamic (MHD) flow through a stretching permeable surface while considering a chemical reaction and convective boundary conditions. A physics-informed neural network (PINN) approach is employed to obtain precise solutions, representing a key novelty of this work. The governing partial differential equations were transformed into nonlinear ordinary differential equations by applying similarity transformations. These equations are integrated into the PINN's loss function to enforce initial and boundary conditions, enabling the model to learn effectively during training. We analyze various parameters related to velocity, thermal, and concentration distributions and present the results graphically. The findings indicate that injecting fluid leads to a reduction in the velocity gradient as the fluid moves away from the surface, whereas suction has the opposite effect, increasing the velocity gradient. The velocity parameter significantly reduces the velocity boundary layer thickness, an effect further enhanced by the magnetic parameter. The thermal and concentration boundary layers are primarily affected by the Schmidt and Prandtl numbers. Additionally, the reaction parameter slows the concentration boundary layer near the sheet, while the convective parameter increases the temperature at the plate's surface. Our proposed method shows significant agreement with previous studies, validating its effectiveness in solving complex MHD flow problems. These findings provide deeper insights into fluid dynamics in MHD flows and have implications for applications involving heat and mass transfer, such as in chemical reactors, cooling systems, material processing, and environmental management.</p>\u0000 </div>","PeriodicalId":44939,"journal":{"name":"Heat Transfer","volume":"54 3","pages":"2001-2012"},"PeriodicalIF":2.8,"publicationDate":"2025-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143801497","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":"Heat and Mass Transport in Magnetized CNT-Infused Hybrid Ellis Nanofluid Flow Over a Porous Stretching Surface","authors":"M. N. Pooja,&nbsp;S. K. Narasimhamurthy,&nbsp;Kuppalapalle Vajravelu","doi":"10.1002/htj.23270","DOIUrl":"https://doi.org/10.1002/htj.23270","url":null,"abstract":"<div>\u0000 \u0000 <p>The overarching aim of this study is to investigate the enhancement of thermal energy and mass transfer in the flow of Ellis hybrid nanofluid under a magnetic field across a porous stretching surface. This advanced hybrid nanofluid is formulated by dispersing single-walled and multiwalled carbon nanotubes (CNTs) within a non-Newtonian Ellis fluid. The research meticulously analyzes the complex interactions of velocity, heat, and mass transport influenced by thermal radiation, nonuniform heat sources/sinks, Joule heating, and Arrhenius activation energy. The governing nonlinear partial differential equations are skillfully transformed into ordinary differential equations through elegant similarity transformations, and the resulting dimensionless equations are solved semianalytically using the sophisticated Homotopy Analysis Method. The key findings indicate that viscous dissipation and heat generation significantly elevate energy profiles, while Arrhenius activation energy profoundly boosts mass transfer rates. Additionally, the integration of CNTs into the Ellis fluid enhances both velocity and energy fields, demonstrating remarkable improvements in heat and mass transfer efficiency. The Ellis hybrid nanofluid holds immense potential for applications in engineering and industrial processes, including polymer extrusion, food processing, and pharmaceutical manufacturing, where precise control of shear-thinning fluid behavior is vital for optimizing performance.</p>\u0000 </div>","PeriodicalId":44939,"journal":{"name":"Heat Transfer","volume":"54 3","pages":"2013-2031"},"PeriodicalIF":2.8,"publicationDate":"2025-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143801500","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":"Infrared-Assisted Hot Air Drying of Turmeric Slices: Effects on Drying Kinetics, Quality, Efficiency, Energy Considerations, and Mathematical Modeling","authors":"G. Jeevarathinam,&nbsp;R. Pandiselvam,&nbsp;T. Pandiarajan,&nbsp;J. Deepa,&nbsp;S. Dinesh Kumar,&nbsp;P. Preetha,&nbsp;T. Krishnakumar,&nbsp;A. Asha Monicka,&nbsp;M. Balakrishnan,&nbsp;D. Amirtham","doi":"10.1002/htj.23261","DOIUrl":"https://doi.org/10.1002/htj.23261","url":null,"abstract":"<div>\u0000 \u0000 <p>The commercial value of turmeric is significantly influenced by the percentage of volatile compounds. Drying techniques reported in previous studies for turmeric showed a reduction in volatile compounds, which negatively affected the quality and market value. In this investigation, drying trials were conducted on turmeric slices with bed thicknesses ranging from 10–25 and 10–50 mm using infrared drying, hot air drying (HAD), and infrared-assisted hot air drying (IR-HAD) methods at temperatures of 50°C, 60°C, and 70°C. The air velocity was maintained at 2 m/s, with an infrared radiation intensity of 3.02 W/cm². The results indicated that IR-HAD at 70°C with a bed thickness of 25 mm achieved the best outcomes in terms of drying rate, efficiency, specific energy consumption, and CO₂ emissions. Conversely, IR-HAD at 60°C with a bed thickness of 25 mm was optimal for retaining quality parameters, such as curcumin, oleoresin, color, and starch content. Notably, the drying time at 70°C for the 10–25-mm bed thickness was 54.54% shorter compared with 50°C for IR-HAD. Statistical analysis revealed significant effects (<i>p</i> &lt; 0.01) of drying techniques, bed thickness, and drying temperatures on quality parameters. IR-HAD at 60°C with a bed thickness of 25 mm emerged as the preferred operating condition for producing high-quality turmeric. Nonlinear regression analysis confirmed the suitability of seven different thin-layer drying models, with the page model being the most accurate predictor of turmeric slice drying under varied conditions. IR-HAD demonstrated its potential to accelerate the drying rate during the initial stage of the process, with reduced thickness proving more effective due to the increased surface area facilitating faster moisture removal. IR-HAD at 60°C retains the maximum percent of volatile compounds and maintains the quality by faster and uniform drying. Therefore, employing IR-HAD offers a more energy-efficient sustainable method while ensuring quality retention in dried turmeric slices.</p>\u0000 </div>","PeriodicalId":44939,"journal":{"name":"Heat Transfer","volume":"54 3","pages":"1965-2000"},"PeriodicalIF":2.8,"publicationDate":"2025-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143801374","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":"Investigation of Heat Transfer of Nanoencapsulated Phase Change Material and Water in a Trapezoidal Cavity With a Sliding Wall","authors":"Obai Younis,&nbsp;Yacine Khetib,&nbsp;Aissa Abderrahmane,&nbsp;Khalid H. Almitan,&nbsp;Houssem Laidoudi,&nbsp;Abdeldjalil Belazreg,&nbsp;Awadallah Ahmed","doi":"10.1002/htj.23273","DOIUrl":"https://doi.org/10.1002/htj.23273","url":null,"abstract":"<div>\u0000 \u0000 <p>In recent years, nanoencapsulated phase change materials (NEPCMs) have gained great interest in thermal management and control applications. This paper addresses the mixed convection of water and NEPCM confined within a lid-driven trapezoidal cavity. The bottom wall of the cavity is of a wavy shape; moreover, the cavity includes a hot flame and is subjected to a magnetic field. The Galerkin-finite element method was used to address the system governing equations and the results obtained were validated by preceding research works. The impacts of bottom wall undulation number (<i>N</i> = 1–4), Hartmann number (<i>Ha</i>) of 0–100, Reynolds number (<i>Re</i>) of 0–500, and hot flame location (left, center, and right) on thermal fields and flow pattern are presented and discussed. The findings show that placing the hot flame at the center gives the maximum thermal transfer rate while augmenting the undulation number of the bottom wall obstructs the liquid flow and hence reduces heat transmission rates. At the maximum Reynolds number, increasing the undulation number of the bottom wall from 1 to 4 and <i>Ha</i> from 0 to 100 reduces the Nusselt number by 26.7% and 54%, respectively.</p>\u0000 </div>","PeriodicalId":44939,"journal":{"name":"Heat Transfer","volume":"54 3","pages":"1952-1964"},"PeriodicalIF":2.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143801325","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":"Mixed Convective and Nonuniform Internal Heat Generation Effect on Hydromagnetic Micropolar Fluid Flowing Across a Permeable Stretchy Wall: A Numerical Investigation","authors":"R. A. Oderinu,&nbsp;F. J. Ayanbukola,&nbsp;S. Alao,&nbsp;B. A. Sanusi,&nbsp;T. A. Oyeyinka","doi":"10.1002/htj.23271","DOIUrl":"https://doi.org/10.1002/htj.23271","url":null,"abstract":"<div>\u0000 \u0000 <p>The quest to efficiently manage heat generation/absorption in industries, such as chemical production, mechanical machines, oil exploration, and aeronautical engineering, is in high demand. This study is conducted to examine the impacts of internal heat generation/absorption as well as unsteady mixed convection of the micropolar fluid through a permeable channel. The formulated nonlinear fundamental equations converted from partial differential equation to ordinary differential equation are numerically analyzed and solved using the Laguerre Collocation Method along with Gauss–Lobatto points. To verify the simulation's accuracy, validation is performed via shooting technique with the fourth-order Runge–Kutta method acting as the control method with the aid of Mathematica 11.0 software. The behavior of the flow was influenced by various physical parameters, which were analyzed using plots and tables. Impacts of skin friction, Sherwood number, and Nusselt number are evaluated. The findings reveal that an improvement in the micropolar term leads to an enhancement in temperature and velocity while angular momentum declines. Additionally, it was revealed that an increase in nonuniform heat generation parameters, magnetic term, and Eckert number improves the temperature profile, while the greater Grashof number results in an enhancement in the velocity profile.</p>\u0000 </div>","PeriodicalId":44939,"journal":{"name":"Heat Transfer","volume":"54 3","pages":"1940-1951"},"PeriodicalIF":2.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143801326","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}