Heat Transfer最新文献

{"title":"Characteristics of thermo‐hydraulic flow inside corrugated channels: Comprehensive and comparative review","authors":"Fatimah Q. Al-Daamee, Naseer H. Hamza","doi":"10.1002/htj.23136","DOIUrl":"https://doi.org/10.1002/htj.23136","url":null,"abstract":"Previous works that investigated the characteristics of heat transfer and fluid flow in channels with corrugated walls have been extensively reviewed in this study. In accordance with the fast increase in power consumption requirements, many researchers have investigated a new approach for cooling techniques that can enhance the cooling performance of devices without consuming more power. To improve the efficiency of energy systems, many investigators and engineers implement promising techniques such as surface optimization and additives as passive methods to augment the rates of heat transfer. Researchers investigated different corrugation profiles along with various working fluids as well as external power devices to further improve the heat exchange process of thermal systems. The aim of this article is to give a clear preview of the effects of different parameters such as wave parameters, Reynolds number, type of working fluid, and pulsating flow condition on the average and local Nusselt number, the pressure drop, the performance factors, and irreversibility. The main findings are listed in tables and depicted in figures, the matter that helps engineers and researchers to choose a suitable channel shape for their applications.","PeriodicalId":44939,"journal":{"name":"Heat Transfer","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141800297","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":"Unsteady flow past an impulsively started infinite vertical plate in presence of thermal stratification and chemical reaction","authors":"Nitul Kalita, Himangshu Kumar, Rupam Shankar Nath, R. Deka","doi":"10.1002/htj.23137","DOIUrl":"https://doi.org/10.1002/htj.23137","url":null,"abstract":"The purpose of this study is to analyze how thermal stratification affects fluid movement past an impulsively initiated infinite upright plate when first‐order chemical reactions are present. Laplace's transform method is applied to achieve a closed‐form solution for the nondimensional governing equations when . The formula , where t is the time and s is a parameter, can be used to obtain the Laplace transform of an exponentially ordered piece‐wise continuous function . The unstable flow past an infinite vertical plate, starting abruptly in the presence of heat stratification and chemical reactions, has never been studied before. The research focuses on the combined impact of thermal stratification and chemical processes on the flow of an incompressible viscous fluid over an indefinitely tall plate. In this study, the significant findings that resulted from heat stratification are compared to the condition in which heat stratification is absent. The impacts of a number of parameters, such as are investigated and visually displayed with respect to the following variables: concentration, velocity, shear stress, rate of heat transfer, temperature, and rate of mass transfer. It is demonstrated that applying stratification increases the frequency of oscillation in shear stress and heat transfer rate. The results obtained can be useful in the design of heat exchangers and other engineering applications.","PeriodicalId":44939,"journal":{"name":"Heat Transfer","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141801408","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":"A comparison between Hankel and Fourier methods for photothermal radiometry analysis","authors":"Raza Sheikh, Quentin Pompidou, Ezekiel Villarreal, Nicolas Horny, Heng Ban","doi":"10.1002/htj.23134","DOIUrl":"https://doi.org/10.1002/htj.23134","url":null,"abstract":"Photothermal radiometry has recently been investigated for use in the multidimensional thermal characterization of anisotropic samples. In application, there are two principal thermal models available for such characterization: a Cartesian model for the heat equation, which requires the application of three Fourier transforms to arrive at a solution (dubbed the Fourier technique), and a cylindrical model for the heat equation, which requires the application of a Hankel transform and a single Fourier transform (dubbed the Hankel technique). The Fourier technique allows for three‐dimensional characterization, while the Hankel technique is expected to greatly reduce the computational time required. As these models can be very computationally expensive, the potential to reduce this cost is of great interest. In this work, these multidimensional models are presented after which they are compared for accuracy, computational time, and assumption limitations. It was found that both the Fourier and Hankel techniques could accurately arrive at desired thermal properties, but that the Hankel Technique reduced the computational time by between 100× and 250× depending upon mesh spacings. Accuracy limitations were found as the eccentricity of the heating laser was increased with a less than 13% error being induced from a beam with a 3–1 axis ratio. The Hankel technique shows ideal application in computationally expensive models which employ a relatively circular beam shape.","PeriodicalId":44939,"journal":{"name":"Heat Transfer","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141803674","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":"Recent advancements in flow control using plasma actuators and plasma vortex generators","authors":"Md. Abdullah, Muhammad Taharat Galib, Md. Shawkut Ali Khan, Tamanna Rahman, Md. Mosharrof Hossain","doi":"10.1002/htj.23131","DOIUrl":"https://doi.org/10.1002/htj.23131","url":null,"abstract":"Flow‐control techniques have attracted significant attention in many scientific areas due to their ability to improve the effectiveness and regulate the flow of aerodynamic devices. This study explores the latest developments in flow‐control techniques, specifically concentrating on the cutting‐edge technologies of plasma vortex generators (PVGs) and actuators. By taking advantage of the ionization of gases or air, plasma actuators have become a viable method for modifying an object's aerodynamic properties without needing physical moving parts. These actuators create localized plasma discharges that interact with the surrounding flow to provide accurate separation control, boundary‐layer dynamics, and aerodynamic forces on aircraft wings, wind turbine blades, and other surfaces. PVG, which produce controlled vortical structures, offer a novel way to manipulate airflow with plasma actuators. These generators create swirling motions through plasma discharges that can be used in various technical applications, such as automotive, marine, and aviation, to modify boundary layers, reduce drag, and improve lift characteristics. This study offers an overview of recent work, focusing on the theoretical underpinnings, experimental validations, and practical applications of plasma‐based flow‐control technologies. Advances in plasma‐generating techniques, computational modeling approaches, and experimental configurations to optimize and comprehend the intricate fluid–structure interactions are covered in the debate. Moreover, the study delves into incorporating plasma‐based flow management into cars, renewable energy systems, and next‐generation aerospace designs, highlighting the possibility of increased agility, decreased emissions, and efficiency. It also discusses the difficulties and potential paths for developing these technologies further for use in business and industry, highlighting the necessity of dependable, scalable, and durable solutions. Finally, this study summarizes the most recent advancements in vortex generators and plasma actuators for flow control. It demonstrates how they have the power to revolutionize fluid dynamics and aerodynamics in a variety of engineering fields.","PeriodicalId":44939,"journal":{"name":"Heat Transfer","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141807301","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":"Optimization of the cold‐side heat exchanger design to improve the performance of the motorcycle exhaust thermoelectric generator","authors":"T. D. Hong, Duc Tam-Hong Nguyen, M. Q. Pham, Em Bao Van Huynh, Tien Anh Tran","doi":"10.1002/htj.23132","DOIUrl":"https://doi.org/10.1002/htj.23132","url":null,"abstract":"This study optimizes the main parameters of the cold‐side heat exchanger (CHE) longitudinal fin, including fin quantity (Nf), fin thickness (Tf), and fin height (Hf), to enhance the performance of motorcycle exhaust thermoelectric generator units (TGUs) utilizing the computational fluid dynamics approach. The investigation shows that these parameters significantly affect the dissipation area of the CHE heat and the outside air velocity distribution in fin gaps, resulting in the fluctuation of TGU output power. The output power increases with respect to Hf; nevertheless, it first increases as Nf and Tf increase but decreases dramatically when Nf or Tf becomes too large. Besides, Hf significantly affects output power, and its impact is almost independent of Tf and Nf, and vice versa; meanwhile, Tf and Nf have a strong relation. This study proposes two Hf of 40 and 60 mm along with the optimal Tf of 1 mm and Nf of 29, providing significantly high output power, low weight, and compact size for TGU. This work contributes insight into the effect of CHE parameters on the TGU performance, and it is a crucial case study for selecting suitable heat sink parameters for TGU, considering practical requirements and conditions.","PeriodicalId":44939,"journal":{"name":"Heat Transfer","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141815155","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 heat transfer in an open cavity with fins","authors":"Mohammed Abu‐Ghurban, Khaled Al‐Farhany","doi":"10.1002/htj.23128","DOIUrl":"https://doi.org/10.1002/htj.23128","url":null,"abstract":"This work numerically explores the mixed convective heat transfer in an open square enclosure containing conducting fins fixed to the heated vertical wall. This kind of work with fins has enormous potential due to its applications in research, engineering, and current industries. Therefore, the current work is highly significant to understand the impact of mixed convection. The external flow enters from the hole in the bottom wall and leaves from the hole in the upper wall. The left vertical wall of the enclosure is heated isothermally, and the fins are attached to the heated walls at a uniform height. Both the upper and lower walls are adiabatic, whereas the right sidewall is at a lower temperature. The non‐dimensional transport equations are resolved by using the finite element method. The study is accomplished for the wide control variables range, such as Reynolds number (50 ≤ Re ≤ 200), Richardson's number (0.1 ≤ Ri ≤ 10), the length of the fins (Lf = 0.2, 0.4, and 0.6), the size of the outlet opening (Wout = 0.1, 0.2, and 0.3), and the gaps in between the outlet hole and left heated wall (S = 0, 0.45, and 0.9). The results show that the thermal performance of the open enclosure is meaningfully affected by the control parameters. The maximum and minimum heat transfer happens when the position of the outlet opening is at the left (S = 0) and right (S = 0.9), respectively. The heat transfer improves by raising the Ri and Re, whereas increasing the fin's length and distance between the outlet opening and left wall reduces heat transfer significantly. The rises 13% with a decrease in the fin's length from 0.6 to 0.2 at Re = 200, S = 0 due to the improvement of the convection on the heated wall. Also,  increases by 15% when Ri increases from 1 to 9.","PeriodicalId":44939,"journal":{"name":"Heat Transfer","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141829527","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":"The variational approach to study the mixed convection boundary layer flow over a permeable Riga plate","authors":"Chandrasekar Muthukumaran, Anitha Semmandapatti Mohankumar, Kasiviswanathan Malayampalayam Sathasivam","doi":"10.1002/htj.23130","DOIUrl":"https://doi.org/10.1002/htj.23130","url":null,"abstract":"The physical problem of steady state, laminar, mixed convection (Ri) with double‐diffusive (N) in an electrically low conducting fluid past a semi‐infinite electromagnetic () influenced flat plate with internal uniform heat generation (Q) in the presence of suction/injection (H) by considering viscous dissipation (Ec), thermophoresis (Nt) and thermal diffusion effects (Sr) is mathematically modeled as a simultaneous system of nonlinear partial differential equations. To achieve the solution of the problem numerically, Gyarmati's variational principle known as the “Governing Principle of Dissipative Processes” on the basis of nonequilibrium thermodynamic processes in the theory of continua, is adopted. This research work correlates the phenomenon of fluid around submersibles/space vehicles and provides related insights. To estimate the transportation fluid fields within the boundary layer, the appropriate trial polynomials have been employed, and functionals for the integral variational principle are determined. Next, the Euler–Lagrange equations of the functionals are obtained as a system of polynomial equations involving boundary layer thicknesses of momentum, temperature, and concentration. The expressions of local shear stress, local Nusselt, and local Sherwood numbers have been derived and the effects of various physical factors involved in the problem are explored. A comparison with the previously published results in the literature is provided to confirm the validity of the solution procedure. The results depict that injection () and opposing buoyancy () decrease the skin friction about 38% in sea water and 11% in ionized air when compared to impermeable plate for . The aiding buoyancy () plays a dominant role in heat and mass transfers, respectively, with the massive gradients of 340% and 763% in magnitude for the heavier fluid sea water flow while 47% and 3% for the lighter fluid ionized air flow when . The buoyancy parameters (Ri, N) decrease the heat transfer, but increase the mass transfer.","PeriodicalId":44939,"journal":{"name":"Heat Transfer","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141829000","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 thermohydraulic flow and enhancement heat performance in 3D dimple tube based on varying geometrical configurations","authors":"Saad Raad Al-Haidari,&nbsp;Ahmed Ramadhan Al-Obaidi","doi":"10.1002/htj.23085","DOIUrl":"10.1002/htj.23085","url":null,"abstract":"<p>This research work investigates how different dimple designs affect the flow field and thermal performance of three-dimensional pipes. The study focuses on the effect of the number of improved dimples NOD (3, 4, and 5), different groups numbers DGNs (1, 2, and 3 groups), arranged around the pipe, and different distances between dimples (DBDs). Dimple geometry affects flow: Changing dimple parameters alters the velocity and pressure distribution within the pipe. Performance evaluation factor (PEF) varies with dimple configuration: The PEF, which balances heat transfer enhancement and pressure drop penalty, ranges from 1.187 to 1.23 for NOD and from 1.292 to 1.31 for DGN, and also from 1.26 to 1.302 for DBD. Reynolds number range, <i>Re</i> = 4000–15,000; turbulence model, standard <i>k</i>–<i>ε</i> model; numerical scheme, second-order upwind scheme; test tube conditions, inlet temperature (<i>T_in</i>) = 25°C; pipe diameter <i>D</i> = 23 mm; thickness = 2 mm; heat flux <i>q</i> = 25,500 W/m²; and material (Cu). This research focuses on improving heat transfer efficiency in pipes using dimples. Dimple size and arrangement significantly impact flow dynamics and heat transfer. PEF is used to evaluate the overall performance considering both heat transfer improvement and pressure drop penalty. The study found a specific range for PEF under various conditions for different dimple configurations. The average enhancement in Nusselt number for model 2 was 15.16% compared with a smooth pipe and the heat transfer performance by 10.028%–28.963% at the effect of NOD, the DGN has slightly higher <i>Nu</i> values than smooth pipes, indicating improved heat transfer due to the dimples (around 7%–58% at <i>Re</i> 4000–15,000 and 9%–13% at <i>Re</i> 12,000), and at DBD (13.5%) at a Reynolds number of 12,000 and 4.6%–59% at <i>Re</i> 4000–15,000.</p>","PeriodicalId":44939,"journal":{"name":"Heat Transfer","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141112995","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":"Multi-objective optimization of a Fibonacci phyllotaxis micro pin-fin heat sink","authors":"Ayechew Shemelash,&nbsp;Bimrew Tamrat,&nbsp;Muluken Temesgen,&nbsp;Rajendiran Gopal,&nbsp;Belachew Desalegn,&nbsp;Hailemariam Mulugeta,&nbsp;Henok G/yohannes Solomon","doi":"10.1002/htj.23083","DOIUrl":"10.1002/htj.23083","url":null,"abstract":"<p>There are still significant technical challenges associated with thermal management of electronic devices such as microprocessors. To improve heat dissipation performance of integrated circuits, a new Fibonacci phyllotaxis design of circular micropin fin heat sinks has been developed. To minimize both chip temperature and pumping power, a multi-objective optimization technique was employed. The effect of design parameters such as phyllotaxis coefficient, pin fin diameter, and pin fin height on response parameters was numerically investigated using the full factorial design of the experiment. Artificial neural network was coupled with MO-Jaya, to arrive at a Pareto frontier of optimal compromise solutions. The optimal set of design variables were found to be a height of 300 μm, a diameter of 122.6 μm, and a phyllotaxis coefficient of 130 μm with an inlet velocity of coolant 2.263 m/s. The selected optimum design was then investigated numerically, and the outcomes were compared to those predicted by the MO-Jaya algorithm. The final confirmed response variables were a maximum temperature of 51.6°C and a pumping power of 0.191 W. The results show that the Fibonacci phyllotaxis structure of the micro pin fin heat sink has better heat-dissipating performance.</p>","PeriodicalId":44939,"journal":{"name":"Heat Transfer","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141115491","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":"Free convective heat transfer induced inside a vented duct having two aligned hot and cold cylinders: An experimental study","authors":"Omar Rafae Alomar,&nbsp;Omar Mohammed Ali,&nbsp;Shaswar Omar Osman Al-Omar","doi":"10.1002/htj.23067","DOIUrl":"10.1002/htj.23067","url":null,"abstract":"<p>Free convective heat transfer created from two aligned cylinders immersed inside a vented air duct is experimentally investigated. The experiments include the measurements of cylinders temperature and the air temperature inside the enclosure under steady, turbulent, and incompressible flow properties by using steady-state heat equations. The studied parameters include Rayleigh number (<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msup>\u0000 <mn>10</mn>\u0000 \u0000 <mn>5</mn>\u0000 </msup>\u0000 \u0000 <mo>≤</mo>\u0000 \u0000 <mi>Ra</mi>\u0000 \u0000 <mo>≤</mo>\u0000 \u0000 <msup>\u0000 <mrow>\u0000 <mn>3.4</mn>\u0000 \u0000 <mo>×</mo>\u0000 \u0000 <mn>10</mn>\u0000 </mrow>\u0000 \u0000 <mn>6</mn>\u0000 </msup>\u0000 </mrow>\u0000 <annotation> ${10}^{5}le {Ra}le {3.4times 10}^{6}$</annotation>\u0000 </semantics></math>), opening sizes at lower and upper enclosure surfaces (<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mn>0.146</mn>\u0000 \u0000 <mo>≤</mo>\u0000 \u0000 <mi>O</mi>\u0000 \u0000 <mo>≤</mo>\u0000 \u0000 <mn>1</mn>\u0000 </mrow>\u0000 <annotation> $0.146le Ole 1$</annotation>\u0000 </semantics></math>), and space size between cylinders (<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mn>0.35</mn>\u0000 \u0000 <mo>≤</mo>\u0000 \u0000 <mi>S</mi>\u0000 \u0000 <mo>≤</mo>\u0000 \u0000 <mn>0.532</mn>\u0000 </mrow>\u0000 <annotation> $0.35le Sle 0.532$</annotation>\u0000 </semantics></math>) with the constant ratio of enclosure width to cylinder diameter equal to 6. The findings displayed that the average air temperature inside the enclosure for the low values of <i>S</i> and <i>O</i> is low, and it rises as <i>S</i> is raised. The behaviors of <i>Nu</i> differ with changing <i>Ra</i> values. An interaction between hot cylinder and cold cylinder inside the enclosure is observed that depends on <i>O</i> and <i>S</i> values, and hence, they have a large impact on fluid temperature. The data indicated that <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>Nu</mi>\u0000 </mrow>\u0000 <annotation> ${Nu}$</annotation>\u0000 </semantics></math> rises with the <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>Ra</mi>\u0000 </mrow>\u0000 <annotation> ","PeriodicalId":44939,"journal":{"name":"Heat Transfer","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141113770","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}