Nanoscale and Microscale Thermophysical Engineering最新文献_第4页

Nanoscale fluid pumping using a symmetric temperature gradient: a molecular dynamics study 使用对称温度梯度的纳米流体泵送：分子动力学研究

IF 4.1 3区工程技术

Nanoscale and Microscale Thermophysical Engineering Pub Date : 2022-05-01 DOI: 10.1080/15567265.2022.2070561

M. Sahebi, A. Azimian

引用次数: 1

Interfacial thermal conductance between gold and SiO2: A molecular dynamics study 金与SiO2界面热导率的分子动力学研究

IF 4.1 3区工程技术

Nanoscale and Microscale Thermophysical Engineering Pub Date : 2022-01-02 DOI: 10.1080/15567265.2022.2066585

S. M. Hatam-Lee, F. Jabbari, A. Rajabpour

引用次数: 2

Thermal Protection Performances of the Macro and/or Nano Enhanced PCM in a Representative Battery Pack 代表性电池组中宏观和/或纳米增强PCM的热保护性能

IF 4.1 3区工程技术

Nanoscale and Microscale Thermophysical Engineering Pub Date : 2022-01-02 DOI: 10.1080/15567265.2022.2069615

Umit Nazli Temel, Ferhat Kilinc, Serkan Coşkun

引用次数: 1

Thermal Annealing and Doping Induced Tailoring of Phase and Upconversion Luminescence of NaYF4:Yb Er Microcrystals 热退火和掺杂诱导的NaYF4:Yb Er微晶体的相位裁剪和上转换发光

IF 4.1 3区工程技术

Nanoscale and Microscale Thermophysical Engineering Pub Date : 2022-01-02 DOI: 10.1080/15567265.2022.2028044

Shivanand H. Nannuri, Sana Adnan, Subash C K, S. C, S. George

{"title":"Thermal Annealing and Doping Induced Tailoring of Phase and Upconversion Luminescence of NaYF4:Yb Er Microcrystals","authors":"Shivanand H. Nannuri, Sana Adnan, Subash C K, S. C, S. George","doi":"10.1080/15567265.2022.2028044","DOIUrl":"https://doi.org/10.1080/15567265.2022.2028044","url":null,"abstract":"ABSTRACT The influence of Mn2+ ion concentration (x = 0–20 mol%) as well as the role of thermal-annealing temperature (400–600°C) on the structural as well as luminescence properties of NaYF4:Yb, Er (Y: 78-x%, Yb: 20%, Er: 2%) microcrystals prepared via a coprecipitation method is investigated. The cubic phase of the as-prepared NaYF4:Yb, Er (Y: 78%, Yb: 20%, Er: 2%) was found to remain intact upon the addition of the Mn2+ ions, but the thermal-annealing elucidates that the phase of the sample depends upon the annealing temperature as well as the Mn2+ ion concentration. Among the Mn2+ ion co-doped samples, 3 mol% doped samples dominant to have a maximum positive influence on the upconversion luminescence of the sample, and a further increase in concentration leads to the concentration-induced quenching of the upconversion luminescence. Moreover, the enhancement factor of green ( ), as well as red ( ) emission, depend upon the annealing temperature, with a maximum enhancement factor of 5 and 3.12 times for the sample annealed at 400°C, 8.6 and 7.25 times for the sample annealed at 500°C, and 6 and 4 times for the sample annealed at 600°C, as compared to Mn2+ ion undoped samples. The maximum emission strength for the green as well as red is observed for the sample annealed at 600°C and co-doped with 3 mol Mn2+ ions. The laser power-dependent study on all the samples shows that the upconversion process is a multi-photon process, predominantly a two-photon process. Graphical abstract","PeriodicalId":49784,"journal":{"name":"Nanoscale and Microscale Thermophysical Engineering","volume":"26 1","pages":"1 - 16"},"PeriodicalIF":4.1,"publicationDate":"2022-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48912026","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}

引用次数: 3

Evaluation of Thermal Hydraulic Characteristics of a Two Phase Superhydrophobic Microfluidic Device using Volume of Fluid Method 用流体体积法评价两相超疏水微流控装置的热水力特性

IF 4.1 3区工程技术

Nanoscale and Microscale Thermophysical Engineering Pub Date : 2022-01-02 DOI: 10.1080/15567265.2022.2070562

U. Aziz, M. Nadeem, Feng Xin, M. Kiliç, A. Ullah

引用次数: 1

Experimental Investigation on Flow Past an Isolated Micro Pin Fin Embedded in a Microchannel 嵌入微通道的孤立微针鳍流动的实验研究

IF 4.1 3区工程技术

Nanoscale and Microscale Thermophysical Engineering Pub Date : 2021-12-27 DOI: 10.1080/15567265.2021.2019861

Can Ji, Zhigang Liu, Mingming Lv, Ji-chao Li

{"title":"Experimental Investigation on Flow Past an Isolated Micro Pin Fin Embedded in a Microchannel","authors":"Can Ji, Zhigang Liu, Mingming Lv, Ji-chao Li","doi":"10.1080/15567265.2021.2019861","DOIUrl":"https://doi.org/10.1080/15567265.2021.2019861","url":null,"abstract":"ABSTRACT Micro pin fin heat sink is a very attractive cooling technique for high power density microelectronics. Optimization of its cooling performance requires insightful understanding on fundamental physics of flow inside it, especially around a single pin fin. In the present study, an experimental investigation on flow past an isolated low aspect ratio (height-to-diameter ratio) pin fin embedded in a microchannel is conducted using Micro-PIV. The flow field and vorticity distribution at different channel heights under various Reynolds numbers are obtained. Endwall effect is found to play an important role in flow past the pin fin in the microchannel, and the critical Reynolds numbers are larger than that at the conventional scale. Vorticity concentrations are formed on both sides of the pin fin along the shear layer and intensify with the increase in Reynolds number. Flow fields and vorticity distributions at different heights exhibit different characteristics, especially at higher Reynolds numbers, indicating three-dimensionalities of the flow. Viscous resistance of the endwalls leads to lower overall velocity, smaller extent of the recirculation zone and weaker vorticity in flow layer closer to the top and bottom channel walls. Pressure drop and flow resistance characteristics in the microdevice is analyzed. The effect of aspect ratio of the pin fin on the wake flow is also studied, and the results show that three-dimensionalities increase but critical Reynolds numbers decrease with larger aspect ratios. A comparison with flow across micro pin fin arrays is conducted and differences are observed in velocity field and wake flow features.","PeriodicalId":49784,"journal":{"name":"Nanoscale and Microscale Thermophysical Engineering","volume":"26 1","pages":"17 - 39"},"PeriodicalIF":4.1,"publicationDate":"2021-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46507866","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}

引用次数: 2

Three-Dimensional Thermal Stress Effects on Nonlinear Torsional Vibration of Carbon Nanotubes Embedded in an Elastic Medium 三维热应力对弹性介质中碳纳米管非线性扭转振动的影响

IF 4.1 3区工程技术

Nanoscale and Microscale Thermophysical Engineering Pub Date : 2021-10-02 DOI: 10.1080/15567265.2021.2011993

Sardar S. Abdullah, S. Hashemi, N. A. Hussein, R. Nazemnezhad

{"title":"Three-Dimensional Thermal Stress Effects on Nonlinear Torsional Vibration of Carbon Nanotubes Embedded in an Elastic Medium","authors":"Sardar S. Abdullah, S. Hashemi, N. A. Hussein, R. Nazemnezhad","doi":"10.1080/15567265.2021.2011993","DOIUrl":"https://doi.org/10.1080/15567265.2021.2011993","url":null,"abstract":"ABSTRACT Nonlinear torsional vibration of nanorods embedded in an elastic medium under three-dimensional thermal stresses is investigated in this study. The scale effect is introduced to the equation of motion using the nonlocal theory. The nanorods are under the effect of a three-dimensional thermal environment. The elastic medium is modeled by infinite rotational springs around the nanorod. Galerkin’s and He’s variational methods are used to solve the differential equation of motion and obtain torsional frequencies. An uncertainty analysis is done to show the effect of the uncertain parameters on the frequencies. The frequency sensitivities are obtained to demonstrate the frequency sensitivities to uncertain parameters. Effect of temperature changes, elastic medium stiffness, vibration amplitude, nonlocal scale coefficient, and nanorod length and diameter on the nonlinear torsional frequencies are investigated. The effect of temperature on the frequencies is dependent on the values of elastic medium stiffness, vibration amplitude, and nanorod length and diameter.","PeriodicalId":49784,"journal":{"name":"Nanoscale and Microscale Thermophysical Engineering","volume":"25 1","pages":"179 - 206"},"PeriodicalIF":4.1,"publicationDate":"2021-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46112838","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}

引用次数: 5

Local Nonequilibrium Electron Transport in Metals after Femtosecond Laser Pulses: A Multi-Temperature Hyperbolic Model 飞秒激光脉冲后金属中的局部非平衡电子输运:一个多温度双曲模型

IF 4.1 3区工程技术

Nanoscale and Microscale Thermophysical Engineering Pub Date : 2021-09-30 DOI: 10.1080/15567265.2021.1985022

S. Sobolev

{"title":"Local Nonequilibrium Electron Transport in Metals after Femtosecond Laser Pulses: A Multi-Temperature Hyperbolic Model","authors":"S. Sobolev","doi":"10.1080/15567265.2021.1985022","DOIUrl":"https://doi.org/10.1080/15567265.2021.1985022","url":null,"abstract":"ABSTRACT The trend toward miniaturization of electronic devices has increased the interest in nano scale heat transport, particularly, in laser-excited solids where electron–electron thermalization and electron-phonon coupling play a key role. Using a multi-temperature hyperbolic model, which takes into account the coupling between initially non-thermalized electrons and different phonon branches, we obtain a hierarchy of heat conduction equations for the electron temperature, which arises due to multi-length and time scales nature of coupling between different excitations. The hierarchy predicts that the ultrashort laser pulse induces a multi-front temperature wave propagating into the bulk of the material, which includes various heat transport regimes, ranging from the ballistic motion of the initially non-thermalized electrons propagating on the shortest time scale without interaction with the lattice as a temperature discontinuity, to the continuous wave-like temperature fronts arising on the intermediate time scale due to coupling between various excitations, and eventually to the classical Fourier transport on the longest time scale. The model is expected to be useful for modeling heat wave propagation phenomena in heterostructures and metamaterials.","PeriodicalId":49784,"journal":{"name":"Nanoscale and Microscale Thermophysical Engineering","volume":"25 1","pages":"153 - 165"},"PeriodicalIF":4.1,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47005421","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}

引用次数: 9

Optical Analysis and Optimization of Micropyramid Texture for Thermal Radiation Control 用于热辐射控制的微金字塔结构光学分析与优化

IF 4.1 3区工程技术

Nanoscale and Microscale Thermophysical Engineering Pub Date : 2021-08-02 DOI: 10.1080/15567265.2021.1958960

Jonathan Sullivan, Ziqi Yu, Jaeho Lee

{"title":"Optical Analysis and Optimization of Micropyramid Texture for Thermal Radiation Control","authors":"Jonathan Sullivan, Ziqi Yu, Jaeho Lee","doi":"10.1080/15567265.2021.1958960","DOIUrl":"https://doi.org/10.1080/15567265.2021.1958960","url":null,"abstract":"ABSTRACT While anti-reflective properties of pyramid texture are widely used, their use for thermal radiation control has received relatively little attention and the understanding of geometric parameters for design optimization is not well established. Here we use finite-difference time-domain simulations in conjunction with an algorithm to optimize thermal characteristics of micropyramid-textured metallic, ceramic, and polymer materials. Our simulations indicate that the pyramid height-to-base ratio is an effective parameter in developing an engineered thermal response. For nickel, the micropyramids with 2–4 height-to-base ratios over 0.5–4 µm base spans provide near-perfect absorption in 300–2500 nm wavelengths. The electric field analysis shows the optical properties are driven by the effects of localized resonance and field confinement. Our thermal cost function-based optimization has led to micropyramid texture that can have a significant impact on heating or cooling such as the solar absorption increase in nickel from 337 to 982 W/m2, the thermal emission increase in alumina from 106 to 170 W/m2, and the thermal emission increase in PDMS from 160 to 172 W/m2. This work not only provides the understanding of micropyramid properties for thermal radiation control but also presents an algorithmic process that could be used for efficient optical-thermal optimization of geometries beyond micropyramids.","PeriodicalId":49784,"journal":{"name":"Nanoscale and Microscale Thermophysical Engineering","volume":"25 1","pages":"137 - 152"},"PeriodicalIF":4.1,"publicationDate":"2021-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/15567265.2021.1958960","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47078568","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}

引用次数: 4

Temperature and Strain Effects in Micro-Raman Thermometry for Measuring In-Plane Thermal Conductivity of Thin Films 用于测量薄膜平面内热导率的微拉曼测温中的温度和应变效应

IF 4.1 3区工程技术

Nanoscale and Microscale Thermophysical Engineering Pub Date : 2021-04-03 DOI: 10.1080/15567265.2021.1912865

Shouyuan Huang, Yijie Chen, Zhe Luo, Xianfan Xu

引用次数: 3