International Journal of Heat and Fluid Flow最新文献

{"title":"The effect of the outlet air duct design of a centrifugal compressor on the gas-dynamic and heat-exchange characteristics of the air flow","authors":"Leonid Plotnikov","doi":"10.1016/j.ijheatfluidflow.2025.110082","DOIUrl":"10.1016/j.ijheatfluidflow.2025.110082","url":null,"abstract":"<div><div>The specific, technical, and economic indicators of an engine can be significantly increased by using a turbocharger. The relevance of this study is that enhancing the design and physical processes in the elements of a centrifugal compressor can result in improved efficiency and productivity of the turbocharger and engine. The study’s objective was to create design strategies for upgrading the compressor outlet air duct to regulate the gas-dynamic and heat-exchange characteristics of the flow. The compressor outlet air duct of an automobile turbocharger served as the research object, and both the compressor and turbine wheels had a diameter of 61 mm. The scientific novelty of the article consists in the study of physical processes in the turbocharger outlet air duct (other authors’ studies were aimed at the inlet channels) and the development of original designs of outlet air ducts. Two approaches were employed: one to stabilize the flow by using a honeycomb in the air duct and another to increase flow turbulence by applying dimples on the channel surface. The study covered the range of rotor speeds from 20,000 to 60,000 min⁻¹ (1.9·10⁵ &lt; Re &lt; 3.3·10⁵). New experimental data on gas dynamics and heat transfer of flows for different air duct designs were obtained through tests on a laboratory bench and measuring equipment based on constant-temperature anemometers, a pressure sensor, thermocouples, tachometers, and an analog-to-digital converter. It has been shown that the use of a honeycomb in the air duct leads to a drop in air flow of up to 14 %, a decrease in turbulence number of up to 36 %, and an increase in the heat transfer coefficient of up to 21 % compared with the basic design. It was found that the application of dimples in the air duct causes a decrease in air flow of up to 8 %, an increase in the number of turbulences of up to 17 %, and an intensification of heat transfer of up to 25 %. Additionally, a simple examination was done to evaluate the impact of modernized air outlet ducts on the engine’s efficiency and power.</div></div>","PeriodicalId":335,"journal":{"name":"International Journal of Heat and Fluid Flow","volume":"117 ","pages":"Article 110082"},"PeriodicalIF":2.6,"publicationDate":"2025-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145154143","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Application of pressure-sensitive paint to investigate hypersonic shock-wave/boundary-layer interactions","authors":"Angelina Andrade,&nbsp;Eugene N.A. Hoffman,&nbsp;Abinayaa Dhanagopal,&nbsp;Elijah J. LaLonde,&nbsp;Christopher S. Combs","doi":"10.1016/j.ijheatfluidflow.2025.110070","DOIUrl":"10.1016/j.ijheatfluidflow.2025.110070","url":null,"abstract":"<div><div>Surface pressure distributions of a hypersonic shock-wave/boundary-layer interaction have been investigated at an average <span><math><mrow><mi>R</mi><mi>e</mi><mo>=</mo><mn>28</mn><mo>.</mo><mn>2</mn><mspace></mspace><mo>×</mo><mspace></mspace><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>6</mn></mrow></msup><msup><mrow><mi>m</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></math></span> in the Mach 7.2 Wind Tunnel facility located at the University of Texas at San Antonio. A ruthenium-based fast-responding pressure-sensitive paint, made in-house, was applied to a canonical wall-to-wall flat plate with a 33° compression ramp. A static calibration of the paint’s response was used to extract global surface pressure measurements of the hypersonic shock-wave/boundary-layer interaction. The 33° ramp experienced high-pressure regions and “Görtler-like” vortices were observed with a spacing of 3 – 6 <span><math><msub><mrow><mi>δ</mi></mrow><mrow><mn>99</mn></mrow></msub></math></span>. The vortex structure spacing was further investigated using surface oil flow visualization, giving a spacing of 2 – 4 <span><math><msub><mrow><mi>δ</mi></mrow><mrow><mn>99</mn></mrow></msub></math></span>. The separation region showed lower pressures than the ramp, and the lowest pressures recorded appeared from the leading edge of the model to the separation region. In this study, a statistical and spectral analysis of the images was performed globally and at discrete locations along the model. The spectral analysis showed energy peaks on the ramp over a low-frequency band of Strouhal numbers between <span><math><mrow><mi>S</mi><msub><mrow><mi>t</mi></mrow><mrow><mi>δ</mi></mrow></msub></mrow></math></span> 0.00029 – 0.00147. Modal analysis was also performed to further examine the energy content of the structures and sub-structures that appeared on the compression ramp.</div></div>","PeriodicalId":335,"journal":{"name":"International Journal of Heat and Fluid Flow","volume":"117 ","pages":"Article 110070"},"PeriodicalIF":2.6,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145108682","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermal analysis of the novel throat-type micro-channel heat sink: Achieving minimal power consumption and maximal thermal performance","authors":"De-Xin Zhang ,&nbsp;Lai-Shun Yang ,&nbsp;Xiao Lu","doi":"10.1016/j.ijheatfluidflow.2025.110077","DOIUrl":"10.1016/j.ijheatfluidflow.2025.110077","url":null,"abstract":"<div><div>This study numerically investigates, for the first time, the enhanced heat transfer and energy-saving performance of throat-type microchannel heat sinks (TMCSH). Unlike previous works that primarily focused on heat transfer improvement, this research introduces energy conservation efficiency as a new evaluation metric, enabling a joint analysis of thermal and energy-saving characteristics. By comparing with conventional straight-channel structures, the effects of throat opening size, throat length, and throat number on maximum temperature reduction, temperature control efficiency, and energy conservation efficiency are systematically analyzed. The results show that the optimal converging acceleration microchannel (CAM) configuration reduces the maximum temperature by 27 K and lowers energy consumption by 36.4 %. Furthermore, optimal nondimensional design ratios (<em>L</em>_c/<em>D</em>_h = 0.30 and <em>L</em>_t/<em>L</em>_x2 = 0.1) are identified, and multi-throat configurations are shown to further enhance thermal management, achieving up to 80 % energy-saving efficiency. These findings provide new theoretical and practical guidance for designing energy-efficient microchannel heat sinks in high heat flux electronics cooling applications.</div></div>","PeriodicalId":335,"journal":{"name":"International Journal of Heat and Fluid Flow","volume":"117 ","pages":"Article 110077"},"PeriodicalIF":2.6,"publicationDate":"2025-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145105077","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analyzing aerodynamic forces of coherent structures on the NACA0012 airfoil at low to moderate angles of attack","authors":"Te-Yao Chiu ,&nbsp;Hsuan-Yu Huang ,&nbsp;Yi-Ju Chou","doi":"10.1016/j.ijheatfluidflow.2025.110063","DOIUrl":"10.1016/j.ijheatfluidflow.2025.110063","url":null,"abstract":"<div><div>We investigated the contributions of coherent structures to the aerodynamic forces exerted on a National Advisory Committee for Aeronautics 0012 (NACA0012) airfoil at angles of attack (AoA) of 5°, 10° and 15°. Utilizing Proper Orthogonal Decomposition (POD) in conjunction with vorticity force analysis, we assessed their contributions to lift and drag forces at a chord-based Reynolds number of 50,000. At the smallest <span><math><mrow><mi>A</mi><mi>o</mi><mi>A</mi></mrow></math></span>, the primary source of time-varying aerodynamic forces arises from the detachment of the spanwise vortex at the reattachment point. In this case, the zeroth POD mode (mean flow) has the dominant contribution to the total force, with contributions from the first few non-zero POD modes being indistinct. As <span><math><mrow><mi>A</mi><mi>o</mi><mi>A</mi></mrow></math></span> increases to 10°, the first POD mode corresponds to an apparent vortical structure located at the second half section of the chord. The clockwise rotation of this vortical structure leads to a strong re-entrant flow on the airfoil’s suction side, resulting in a positive drag contribution due to the intense shear near the boundary. The second POD mode in the case with <span><math><mrow><mi>A</mi><mi>o</mi><mi>A</mi><mo>=</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>∘</mo></mrow></msup></mrow></math></span> corresponds to a trailing edge vortex (TEV), which counteracts the vortical structure of the first mode, leading to a decrease in drag force. The influence of TEV becomes more pronounced when <span><math><mrow><mi>A</mi><mi>o</mi><mi>A</mi></mrow></math></span> increases further to 15°. However, it is found that the major contribution of the TEV to aerodynamic forces arises from its interaction with the leading edge vortex, rather than from its own resulting vorticity forces.</div></div>","PeriodicalId":335,"journal":{"name":"International Journal of Heat and Fluid Flow","volume":"117 ","pages":"Article 110063"},"PeriodicalIF":2.6,"publicationDate":"2025-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145104338","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Populating the wall layer, one eddy at a time: Resolvent analysis for Wall-Modelled LES","authors":"Zvi Hantsis ,&nbsp;Miles J. Chan ,&nbsp;Nam Hoang ,&nbsp;Beverley J. McKeon ,&nbsp;Ugo Piomelli","doi":"10.1016/j.ijheatfluidflow.2025.110066","DOIUrl":"10.1016/j.ijheatfluidflow.2025.110066","url":null,"abstract":"<div><div>Computational cost precludes direct numerical simulation or wall-resolved large-eddy simulations of non-equilibrium, wall-bounded turbulent flows in realistic conditions. Wall-modelled large-eddy simulations (WMLES) and hybrid RANS/LES methods can be used to analyse these flows at much decreased cost, but require modelling of the near-wall layer and, in particular, a means to address the deficit of turbulent activity, or eddies, in the vicinity of the interface between the outer flow and the wall model. We report a computational framework to populate the wall region with synthetic but realistic eddies and reflect their integrated effect on the flow in the inner layer. Two means of generating spatio-temporal representations for the synthetic eddies are investigated: low-order, resolvent-based representations of the wall layer and a coarse-grained, data-driven spectral proper orthogonal decomposition (SPOD) model, both generated in turbulent channel flow at a friction Reynolds number, <span><math><mrow><mi>R</mi><msub><mrow><mi>e</mi></mrow><mrow><mi>τ</mi></mrow></msub><mo>=</mo><mn>1000</mn></mrow></math></span>. The eddy-augmented WMLES models are then tested in <span><math><mrow><mi>R</mi><msub><mrow><mi>e</mi></mrow><mrow><mi>τ</mi></mrow></msub><mo>=</mo><mn>5000</mn></mrow></math></span> and 20,000 channels and compared with experimental and numerical data. The inherent scaling of the resolvent operator can be used to scale the resolvent model to higher Reynolds numbers (and potentially populate new, self-similar eddies as the wall layer grows in inner units), while the SPOD model is energetically optimal for reconstruction of the flow at Reynolds numbers close to that where it is obtained, but degrades as the Reynolds number is increased. The results show that the effect of the introduction of synthetic eddies is twofold: first, a direct contribution to the stress due to the presence of the synthetic eddies and, second, an improved prediction of the normal Reynolds stresses in the inner layer due to an accompanying, coupled reduction in the time- and length-scales of the variation of the URANS-like velocity in the inner layer. Implications and extensions of the method for more complex flows, for example external boundary layers with pressure gradient and separation, are briefly discussed.</div></div>","PeriodicalId":335,"journal":{"name":"International Journal of Heat and Fluid Flow","volume":"117 ","pages":"Article 110066"},"PeriodicalIF":2.6,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145104336","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Performance study of a biomimetic leaf vein microchannel coupled jet impingement system for high-power chip thermal management","authors":"Kaifei Yang ,&nbsp;Yanjun Zhang ,&nbsp;Bobo Zhang ,&nbsp;Qin Sun ,&nbsp;Weimin Luo ,&nbsp;Kaijun Dong ,&nbsp;Wei Wu ,&nbsp;Qianfang Wang","doi":"10.1016/j.ijheatfluidflow.2025.110054","DOIUrl":"10.1016/j.ijheatfluidflow.2025.110054","url":null,"abstract":"<div><div>With the rapid development of high-power integrated circuits, traditional air cooling fails to meet thermal management demands. Liquid cooling has emerged as a key solution. In this paper, based on research related to microchannel and jet heat transfer technology, a novel approach to addressing the thermal management challenges posed by high-power chips is proposed. The approach involves the design of a new type of lotus leaf vein microchannel coupled jet impingement heat transfer system with diversion channels (DLJ-MCHS), which improves the structure of the lotus leaf vein network by introducing diversion channels. The study applies numerical simulation methods to cool an electronic chip with an 800 W heating power using mineral oil as the coolant and systematically analyses the influence laws of parameters such as the shape of the diversion channel, the spacing between the diversion channels, and the height of the microchannels on the flow heat transfer performance of the DLJ-MCHS. The study’s findings indicate that the circular diversion channel exhibits optimal performance in heat transfer enhancement with minimal change in pressure drop, achieving an 800 W chip maximum temperature reduction of up to 8.47 %, a thermal resistance decrease of 14.24 %, and a temperature difference reduction of 20.50 % compared to the basic bionic structure. It is observed that the chip temperature decreases gradually as the channel spacing narrows. Increasing the height of the microchannels helps to reduce the pressure drop and chip temperature, but the enhancement tends to diminish as the height of the microchannels increases. The study proposes a novel idea and optimization scheme for the thermal design of high-power chips, which has important theoretical significance and practical application value.</div></div>","PeriodicalId":335,"journal":{"name":"International Journal of Heat and Fluid Flow","volume":"117 ","pages":"Article 110054"},"PeriodicalIF":2.6,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145104337","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comprehensive analysis of geometric and thermohydraulic characteristics in single-embossed channels of pillow-plate heat exchangers","authors":"Amirhossein Sabourishirazi,&nbsp;Jong-Leng Liow,&nbsp;Maryam Ghodrat","doi":"10.1016/j.ijheatfluidflow.2025.110068","DOIUrl":"10.1016/j.ijheatfluidflow.2025.110068","url":null,"abstract":"<div><div>This study investigated the geometric and thermohydraulic characteristics of flat- and curve-type single-embossed pillow-plate channels (SEPPCs) elaborately for the first time. These examinations revealed that estimating mean hydraulic diameters (MHDs) in various SEPPCs remains a significant challenge, primarily due to the intricate channel structures. Additionally, assuming identical constant wall temperatures for the thinner and thicker plates of SEPPCs causes thermal uncertainties regarding the influence of conduction heat transfer in these plates. This research addresses these challenges in stainless steel, aluminum, and copper SEPPCs. A procedure for hydroforming simulation based on the finite element method was established to model the structure of SEPPCs reliably. By defining novel dimensionless parameters, improved MHD correlations were developed with estimation errors of 13.54 % and −8.68 % for flat- and curve-type SEPPCs, respectively, compared to simulation results. Compared to existing methods, these correlations improved MHD estimations and identified the MHD extremums. Conjugate heat transfer simulations were applied to study heat transfer in the plates of SEPPCs, revealing how material properties, geometric configurations, and fluid convection shaped temperature distributions. Analysis of the periodic-bulk-temperature ratio revealed that simulations using constant wall temperatures were insufficient to accurately represent the behavior of SEPPCs. Moreover, the development of optimized artificial neural networks facilitated the evaluation of the contributing parameters and resulted in accurate predictions of MHDs in both flat- and curve-type SEPPCs, as well as the average channel plate temperatures in flat-type SEPPCs. The findings of this study on MHD estimations and the critical role of channel wall temperatures offer a solid foundation for advancing research across diverse SEPPC configurations in the future.</div></div>","PeriodicalId":335,"journal":{"name":"International Journal of Heat and Fluid Flow","volume":"117 ","pages":"Article 110068"},"PeriodicalIF":2.6,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145104335","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical investigation of unsteady flow over tandem permeable elliptic and rigid circular cylinders at Reynolds number of 150","authors":"Nhi Ngoc Nguyen ,&nbsp;Wei-Cheng Wang ,&nbsp;Nguyen Dinh Duc ,&nbsp;Yong Cao ,&nbsp;Viet Dung Duong","doi":"10.1016/j.ijheatfluidflow.2025.110048","DOIUrl":"10.1016/j.ijheatfluidflow.2025.110048","url":null,"abstract":"<div><div>This study presents a comprehensive numerical investigation of dynamic flows past a permeable elliptic cylinder and a impervious circular cylinder in tandem arrangement employing lattice Boltzmann method with block-structured topology-confined mesh refinement. Simulations are conducted in wide parameter space of spacing ratio (<span><math><mrow><mi>L</mi><mo>/</mo><mi>D</mi><mo>=</mo><mn>1</mn><mo>.</mo><mn>5</mn><mo>−</mo><mn>5</mn></mrow></math></span>), elliptic cylinder aspect ratio (<span><math><mrow><mi>A</mi><mi>R</mi><mo>=</mo><mn>0</mn><mo>.</mo><mn>2</mn><mo>−</mo><mn>1</mn></mrow></math></span>), and Darcy number (<span><math><mrow><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>−</mo><mn>4</mn></mrow></msup><mo>−</mo><mn>0</mn><mo>.</mo><mn>8</mn></mrow></math></span>) at Reynolds number of 150 (where <span><math><mi>L</mi></math></span> and <span><math><mi>D</mi></math></span> are two cylinder’s spacing and cylinder diameter, respectively). In this space, four vortex regimes are identified as overshoot (OS), reattachment (RA), quasi-coshedding (QS), and co-shedding (CS). At small-to-moderate spacing ratios, only OS and RA regimes occurs, signifying proximity effect over aspect ratio in flow instability with varying permeability; while large spacing ratios reveal all four regimes, with QS and CS appearing at small to moderate permeabilities. The shadowing effect significantly alters the impervious cylinder’s pressure distribution, especially at small spacing ratios. The time-averaged drag coefficient rises as the Darcy number increases, approaching single circular cylinder values. Drag and lift coefficient fluctuations are minimal at small-to-moderate spacing ratios but intensify in QS and CS regimes at large spacing ratios due to shadowing. The time-averaged lift coefficient is adjustable at moderate-to-large spacing ratios in RA, QS, and CS regimes, while the Strouhal number, influenced by proximity and permeability, highlights the porous elliptic cylinder’s role in alternating vortex shedding frequency.</div></div>","PeriodicalId":335,"journal":{"name":"International Journal of Heat and Fluid Flow","volume":"117 ","pages":"Article 110048"},"PeriodicalIF":2.6,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145104334","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Three-dimensional self-propelled flexible plate with time-varying flapping frequency","authors":"Jongmin Yang","doi":"10.1016/j.ijheatfluidflow.2025.110067","DOIUrl":"10.1016/j.ijheatfluidflow.2025.110067","url":null,"abstract":"<div><div>The variation in the flapping frequency of a self-propelled flexible plate over time is analysed, and its transient propulsion is examined using the immersed boundary method. The flapping frequency of the flexible plate is continuously defined as a function of time using a piecewise definition. Inspired by the similarity between the time-dependent variation of the average cruising speed and a step response plot, the settling time and maximum overshoot of behavior of the flexible plate are defined and scrutinized. By controlling the rate of change in the flapping frequency, the power consumption of the flexible plate is optimized. As a result, the flapping frequency of the flexible plate gradually transitions from the most efficient flapping frequency to the flapping frequency that achieves the highest average cruising speed. During this transition, the power consumption of the flexible propulsor is reduced to 1/4 of its original value, while the settling time decreases to approximately 38% of its initial duration. To analyse the propulsion mechanisms of the flexible propulsor from the perspective of vortex dynamics, vortical structures are identified through percolation theory. To investigate the influence of the identified vortical structures on the propulsion mechanisms of the flexible plate, an inverse power law-based formulation is proposed and validated by comparing it with the time-dependent propulsion speed and the power consumption of the flexible propulsor. Such transient propulsion is commonly observed in various operational environments, such as acceleration and deceleration phases of unmanned underwater vehicles (UUVs) and flapping-wing air vehicles (FWAVs). The present work is expected to serve as a foundational investigation for understanding oscillatory motion under these conditions.</div></div>","PeriodicalId":335,"journal":{"name":"International Journal of Heat and Fluid Flow","volume":"117 ","pages":"Article 110067"},"PeriodicalIF":2.6,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145104333","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of branches and secondary connections on performance of Y-fractal heat sink","authors":"Shashank Singh,&nbsp;Anup Malik,&nbsp;Harlal Singh Mali","doi":"10.1016/j.ijheatfluidflow.2025.110053","DOIUrl":"10.1016/j.ijheatfluidflow.2025.110053","url":null,"abstract":"<div><div>The growing demand for compact and high-performance electronic equipment leads to high heat dissipation, which causes failure. To overcome this challenge, microchannel heat sinks (MHS) significantly increase heat transfer rates above conventional techniques by having high surface area-to-volume ratios. In this work, Y-fractal MHS devices with increased branching level and secondary connections are developed by additive manufacturing. Thermo-hydraulic characteristics of the devices are examined by both numerical and experimental approaches. Maximum enhancement of 22.6% in the average Nusselt number (<span><math><mrow><mi>N</mi><msub><mrow><mi>u</mi></mrow><mrow><mi>a</mi><mi>v</mi><mi>g</mi></mrow></msub></mrow></math></span>) is achieved with an increase in the branching level at the expense of 67% pressure drop (<span><math><mrow><mi>Δ</mi><mi>P</mi></mrow></math></span>) penalty. Adding secondary connected channels results in maximum reduction of 23.1% in <span><math><mrow><mi>N</mi><msub><mrow><mi>u</mi></mrow><mrow><mi>a</mi><mi>v</mi><mi>g</mi></mrow></msub></mrow></math></span> with an insignificant effect on <span><math><mrow><mi>Δ</mi><mi>P</mi></mrow></math></span>. Y-fractal MHS with two branches (Y-FMHS-B2) shows the best thermal performance at constant pumping power (<span><math><mrow><mi>P</mi><mi>P</mi></mrow></math></span>) between the comparison range from 0.0016 to 0.005 W.</div></div>","PeriodicalId":335,"journal":{"name":"International Journal of Heat and Fluid Flow","volume":"117 ","pages":"Article 110053"},"PeriodicalIF":2.6,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145105076","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}