ASME 2019 6th International Conference on Micro/Nanoscale Heat and Mass Transfer最新文献_第8页

Investigation on Thermal Conductivity and Viscosity of Thin Water Film by Molecular Dynamics Simulation 用分子动力学模拟研究水薄膜的导热性和粘度

ASME 2019 6th International Conference on Micro/Nanoscale Heat and Mass Transfer Pub Date : 2019-12-02 DOI: 10.1115/mnhmt2019-4087

Lu Jin, Leping Zhou

引用次数: 0

Mechanism Research of Coupling Drag Reduction and Heat Transfer on Surface With Different Liquid-Solid Interaction 不同液固相互作用下表面减阻与传热耦合机理研究

ASME 2019 6th International Conference on Micro/Nanoscale Heat and Mass Transfer Pub Date : 2019-07-08 DOI: 10.1115/mnhmt2019-4180

Lin Shi, Chengzhi Hu, Min-li Bai, Jizu Lv, Yubai Li

引用次数: 0

Molecular Dynamics Study on Effect of Interface Between Silicon and Silicon Carbide Crystals on Phonon Heat Conduction on Nanoscale 纳米尺度下硅与碳化硅晶体界面对声子热传导影响的分子动力学研究

ASME 2019 6th International Conference on Micro/Nanoscale Heat and Mass Transfer Pub Date : 2019-07-08 DOI: 10.1115/mnhmt2019-4114

Xianhua Nie, Li Zhao, S. Deng, Yue Zhang, Zhenyu Du

{"title":"Molecular Dynamics Study on Effect of Interface Between Silicon and Silicon Carbide Crystals on Phonon Heat Conduction on Nanoscale","authors":"Xianhua Nie, Li Zhao, S. Deng, Yue Zhang, Zhenyu Du","doi":"10.1115/mnhmt2019-4114","DOIUrl":"https://doi.org/10.1115/mnhmt2019-4114","url":null,"abstract":"\u0000 Both silicon (Si) and silicon carbide (SiC) are promising materials used in nano-electro-mechanical system (NEMS), however, the understanding on its phonon heat conduction is rare, which restrict the performance improvement of NEMS. Moreover, the effects of the interface between crystals, which could significantly impact the phonon transport, on heat conduction are not sufficient in the existing publication pool. In this paper, two systems, Si/Si and Si/SiC, are simulated at different temperatures and temperature differences using molecular dynamics simulation and the results were analyzed.\u0000 The temperature of Si inside Si/SiC system was set at 280K, and the temperatures of SiC were set as a certain absolute value based on temperature difference setting. Meanwhile, 6 groups of temperature difference are applied as simulated conditions. In addition, simulated results from Si/Si system are also applied in comparative analysis as a reference group. The results suggested that the existence of the interface of Si/SiC system would reduce the capability of heat conduction compared to the heat conduction of Si/Si and reverse temperature differences are discovered. When the average temperature is higher than 280K, the heat conduction rate of Si/SiC system is higher than that of Si/Si system initially and as the temperature differences between crystals increases to 60.90K, the heat conduction rate of Si/Si system is higher than that of Si/SiC system. Similar conclusion can also be obtained when the average temperature is lower than 280K. This work provides an open opportunity to study the effect of interface on phonon heat conduction between crystals at typical temperature differences and average temperatures.","PeriodicalId":331854,"journal":{"name":"ASME 2019 6th International Conference on Micro/Nanoscale Heat and Mass Transfer","volume":"230 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134531164","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}

引用次数: 0

Near Field Radiative Heat Transfer in a Chain of Metallic Particles 金属颗粒链中的近场辐射传热

ASME 2019 6th International Conference on Micro/Nanoscale Heat and Mass Transfer Pub Date : 2019-07-08 DOI: 10.1115/mnhmt2019-4236

Minggang Luo, Junming Zhao, L. Liu

{"title":"Near Field Radiative Heat Transfer in a Chain of Metallic Particles","authors":"Minggang Luo, Junming Zhao, L. Liu","doi":"10.1115/mnhmt2019-4236","DOIUrl":"https://doi.org/10.1115/mnhmt2019-4236","url":null,"abstract":"\u0000 Heat transport mediated by near-field interaction in particulate system (e.g. chain of particles) is one of the research focuses in thermal transport in micro-nanoscale. Near field radiative heat transfer (NFRHT) characteristics of metallic nanoparticle chains (separation distance between neighboring particles is h) are analyzed by means of both coupled electric-magnetic dipole approximation and quadrupole approximation. Thermal conductance (G) between the central particle and other particle with different separation gaps (Δx) is calculated at both 300K and 1200K. Corrected polarizability is used to take quadrupole effect into consideration when calculating the NFRHT in extreme near field where dipole approximation ceases to be valid. Temperature distributions along several different chains of particles due to NFRHT are also predicted. Results show that, according to the asymptotic behavior of distribution of G along metallic chains similar as that observed in SiC chains, heat super-diffusion is demonstrated at both 300K and 1200K in metallic nanoparticle chains. At 300K, the contribution of quadrupole results in that thermal conductance responses to h in different way in metallic and dielectric particle chains. Temperature distribution and heat flow are the two key parameters used to characterize the heat transport in chains of particles. Ag particles in SiC chain act as barriers during the radiative heat transport process. Heat super-diffusion, as well as some other characteristics of NFRHT, observed in metallic nanoparticle chains may help for insight of heat transport in particulate system and new design of device in micro-nanoscale.","PeriodicalId":331854,"journal":{"name":"ASME 2019 6th International Conference on Micro/Nanoscale Heat and Mass Transfer","volume":"116 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128040948","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}

引用次数: 0

Analytical Investigation on the Homogeneous Nucleation in a Mono-Component and Bi-Component Droplet 单组分和双组分液滴均匀成核的分析研究

ASME 2019 6th International Conference on Micro/Nanoscale Heat and Mass Transfer Pub Date : 2019-07-08 DOI: 10.1115/mnhmt2019-3968

Xi Xi, Hong Liu, Chang Cai, M. Jia, Weilong Zhang

引用次数: 0

Numerical Study on the Mechanism of Heat Transfer Enhancement in Fe3O4 Nanoferrofluids With Magnetic Field 磁场作用下Fe3O4纳米流体强化传热机理的数值研究

ASME 2019 6th International Conference on Micro/Nanoscale Heat and Mass Transfer Pub Date : 2019-07-08 DOI: 10.1115/mnhmt2019-4198

Chenfei Wang, D. Gao, Min-li Bai, Peng Wang, Yubai Li

{"title":"Numerical Study on the Mechanism of Heat Transfer Enhancement in Fe3O4 Nanoferrofluids With Magnetic Field","authors":"Chenfei Wang, D. Gao, Min-li Bai, Peng Wang, Yubai Li","doi":"10.1115/mnhmt2019-4198","DOIUrl":"https://doi.org/10.1115/mnhmt2019-4198","url":null,"abstract":"\u0000 Nanofluids is reported to significantly enhance heat transfer but with little cost of pressure loss. To further the enhancement of heat transfer using Fe3O4 nanofluids, a magnetic field is employed to control the trajectory of Fe3O4 nanoparticles. A numerical study is conducted with commercial soft ANSYS FLUENT and the simulations are done with a two-phase flow approach named Euler-Lagrange. By comparing heat transfer of laminar flow in a horizontal tube with magnetic field or not, various volume fraction (0.5%/2%) and Reynolds numbers (Re = 200–1000) are considered. Results show that magnetic field contributes an average 4% promotion in convective heat transfer coefficients compared with the condition of no magnet. The mechanism of the enhancement of heat transfer with magnetic field is explored based on the analysis of velocity field. Fe3O4 Nanoparticles move up and down under the magnetic force, and convective heat transfer is enhanced because of the disturbance of the Fe3O4 nanoparticles. Slip flow between the base fluid and nanoparticles also contributes to the enhancement of heat transfer.","PeriodicalId":331854,"journal":{"name":"ASME 2019 6th International Conference on Micro/Nanoscale Heat and Mass Transfer","volume":"359 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129144791","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}

引用次数: 0

Numerical Analysis of Parametric Effects of Tube-Strip Heat Exchanger for Fuel Cell Vehicles 燃料电池汽车管带式换热器参数效应的数值分析

ASME 2019 6th International Conference on Micro/Nanoscale Heat and Mass Transfer Pub Date : 2019-07-08 DOI: 10.1115/mnhmt2019-4033

Xiaoyu Wu, Hengyun Zhang, Zhe‐ming Zhu, Shen Xu, Yuchen Deng

{"title":"Numerical Analysis of Parametric Effects of Tube-Strip Heat Exchanger for Fuel Cell Vehicles","authors":"Xiaoyu Wu, Hengyun Zhang, Zhe‐ming Zhu, Shen Xu, Yuchen Deng","doi":"10.1115/mnhmt2019-4033","DOIUrl":"https://doi.org/10.1115/mnhmt2019-4033","url":null,"abstract":"\u0000 Fuel cell vehicles (FCVs) are facing more severe heat dissipation challenges since the fuel cell stack is required to operate at a lower temperature and thus smaller heat exchanger temperature difference. Thorough analysis of the parametric effects is required to maximize the thermal performance. In this paper, a numerical analysis of the tube-strip heat exchanger is conducted for the targeted application in a high performance passenger FCV. The representative unit cell is used to model the detailed fluid flow and heat transfer at both hot and cold sides in the theoretical framework of volume averaging. Based on the numerical computation over the representative unit cells, the flow, temperature and pressure fields are obtained, which are then utilized to obtain the cell-level heat transfer coefficient between the hot and cold fluids. The obtained heat transfer coefficients are used for the estimation of the heat exchanger thermal performance based on the effectiveness-NTU method. Different air and liquid water flow rates are first examined. Various design parameters such as fin height, fin spacing, fin thickness and fin material are examined through the heat transfer analysis at the unit cell level. Attention is also paid on the improvement of the air-side performance by changing fin shapes to increase the heat transfer coefficient of the heat exchanger. The result shows that the total exchanged heat of the aluminum louvered fin heat exchanger, with fin thickness of 0.06mm, fin height of 5mm and fin spacing of 1mm, can reach 59.24 kW at the liquid flowrate of 120L/min and air velocity of 5m/s.","PeriodicalId":331854,"journal":{"name":"ASME 2019 6th International Conference on Micro/Nanoscale Heat and Mass Transfer","volume":"22 4 Suppl 9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115351249","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}

引用次数: 0

Study on Thermal Control Behavior by Using BaTiO3-Based PTC Materials With Room Temperature Curie Point 具有室温居里点的batio3基PTC材料的热控制行为研究

ASME 2019 6th International Conference on Micro/Nanoscale Heat and Mass Transfer Pub Date : 2019-07-08 DOI: 10.1115/mnhmt2019-4014

Yu Ai-mei, L. Qiang

{"title":"Study on Thermal Control Behavior by Using BaTiO3-Based PTC Materials With Room Temperature Curie Point","authors":"Yu Ai-mei, L. Qiang","doi":"10.1115/mnhmt2019-4014","DOIUrl":"https://doi.org/10.1115/mnhmt2019-4014","url":null,"abstract":"\u0000 Thermal management has become an important issue to be solved in the miniaturization and weight reduction of electronic equipment, especially in the aerospace field. The doped BaTiO3, as a self-regulating heating material, exhibits an attractive application perspective on the thermal control of electrical devices, resulting from its positive temperature coefficient (PTC) property. However, the Curie temperature of most of the doped BaTiO3 material at present is much higher than the operating temperature of the electrical equipment. On this basis, this paper focuses on the controlling of the Curie temperature and thermal control performance of the BaTiO3-based heating component. The polycrystalline Ba1-xSrxTiO3 was synthesized by solid solution reaction. The Curie temperature is tuned by the content of the strontium element, simultaneously the elements Y and Mn are doped to reduce the room temperature resistivity and improve the PTC effect. The X-ray diffraction demonstrates that the bulk phase of the Ba1-xSrxTiO3 generates in the presintering process, while the crystallization of composition has completed during the sintering. Importantly, the Curie temperature of doped Ba1-xSrxTiO3 for x = 0.3 with average particle size of 4.86 μm has shifted to around 38°C, beyond that exhibiting a 2.8-orders magnitude of PTCR jump.\u0000 Results of the thermal control experiment show that, in contrast to the ordinary resistor heater, the heating element based on the BaTiO3 PTC material can achieve lower equilibrium temperature without any auxiliary control methods. Compared to the traditional thermal control system composed by the ordinary resistor, sensor and controller, the novel thermal control system based on PTC heating unit possesses simple structure, lightweight and excellent reliability.","PeriodicalId":331854,"journal":{"name":"ASME 2019 6th International Conference on Micro/Nanoscale Heat and Mass Transfer","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127639949","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}

引用次数: 4