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

{"title":"Evaluation of Existing Frictional Pressure Drop Correlations During Condensation of R410A in Four Horizontal Tubes","authors":"Kunrong Shen, Zhi-chuan Sun, Wei Li, Xiang Ma, Yan He, Yuansheng Lin, Z. Ke, H. Ke","doi":"10.1115/mnhmt2019-4038","DOIUrl":"https://doi.org/10.1115/mnhmt2019-4038","url":null,"abstract":"\u0000 Results are presented here from an experimental investigation on tube side condensation characteristics that took place in four tested tubes — 1EHT-1, 1EHT-2, 4LB and a smooth tube. The equivalent outer diameter of the tubes was 9.52 mm and the inner diameter was 8.32 mm. Condensation tests were conducted using refrigerant R410A at a saturation temperature of 318K, over a mass flow range of 150–450 kgm−2s−1, with inlet and outlet vapor quality of 0.8 and 0.2, respectively. Pressure drop data of the four tested tubes were collected to evaluate five identified prediction correlations based on the separated flow model and the homogeneous flow model. For 1EHT-2 and the smooth tube, all the listed correlations manage to present predictions with the Mean Absolute Relative Deviation (MARD) less than 30%, while they underestimate the frictional pressure drop of the 4LB tube with MARD exceeding 40% averagely. Regarding the experimental data, it is found that the Muller-Steinhagen and Heck correlation presents the most accurate and stable prediction for the 4 tested tubes. The listed homogeneous flow correlations can provide acceptable predictions with MARD ranging from 25% to 40% under a few conditions, but their average predictive accuracies are inferior to that of the separated flow correlations. Consequently, the separated flow approach performs better than the homogeneous flow model in the prediction of frictional pressure drop for our experimental data.","PeriodicalId":331854,"journal":{"name":"ASME 2019 6th International Conference on Micro/Nanoscale Heat and Mass Transfer","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123530921","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":"Experimental Study on Heat Transfer Performance of Pulsating Heat Pipe CPU Radiator","authors":"F. Shang, Qingjing Yang, Jianhong Liu","doi":"10.1115/mnhmt2019-4017","DOIUrl":"https://doi.org/10.1115/mnhmt2019-4017","url":null,"abstract":"\u0000 According to the characteristics of heat dissipation process and the structural characteristics of traditional heat dissipation device, pulsating heat pipe (PHP) and traditional The pin-finned heat sink are used to simulate the cooling process of CPU, so as to meet the cooling requirements of computer CPU. By comparing the heat transfer perform of the two heat sinks under three conditions: the top wall temperature of the heat sink, the wall temperature of the heat sink and the temperature difference between the inlet and outlet of hot water, it can be found that the heat transfer performance of the PHP radiator is better. The experimental results show that in order to further improve the heat dissipation performance of the computer CPU, the CPU radiator device can be manufactured by the PHP device, and the PHP technology has broad application prospects in electronic heat dissipation.","PeriodicalId":331854,"journal":{"name":"ASME 2019 6th International Conference on Micro/Nanoscale Heat and Mass Transfer","volume":"13 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120912855","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":"Three-Dimensional Simulation of Bubble Behavior and Mass Transfer for CO2 Absorption in Nanoabsorbents","authors":"Lirong Li, Y. Kang","doi":"10.1115/mnhmt2019-3944","DOIUrl":"https://doi.org/10.1115/mnhmt2019-3944","url":null,"abstract":"\u0000 CO2 absorption performance in gas-liquid system is affected by nanoparticles. The enhancement mechanisms involved have been extensively paid attention. The CO2 gas bubble behaviors and the characteristics of the nanoparticle motion have been clarified in the present study. The equivalent substitution method is used to regard the liquid with nanoparticles as a continuous term with changed physical properties, that is, nanofluid. Therefore, the volume-of-fluid (VOF) method is employed to well predict the gas bubble behaviors and mass transfer coefficient in nanofluid. It is found that the mass transfer coefficient in the gas-liquid system for CO2 absorption can be significantly enhanced by Al2O3 nanoparticles. With the increase of nanoparticles volume concentration, the surface renewal frequency increases dramatically. The discrete-particle-method (DPM) is adopted to track the motion of nanoparticles. In this way, the deformation of the bubbles and the motion of the nanoparticle are well captured. It is concluded that the enhanced mass transfer coefficient in gas-liquid-nanoparticle system is not only related to the Brownian motion of the particles, but also related to the nanoparticle deduced turbulence in the liquid field.","PeriodicalId":331854,"journal":{"name":"ASME 2019 6th International Conference on Micro/Nanoscale Heat and Mass Transfer","volume":"351 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134366334","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 Flow and Heat Transfer for a New Double-Layered Microchannel Heat Sink","authors":"Huan Liu, Bin Zhang","doi":"10.1115/mnhmt2019-3967","DOIUrl":"https://doi.org/10.1115/mnhmt2019-3967","url":null,"abstract":"\u0000 In this paper, we propose a new type of DL-MCHS to improve the substrate temperature uniformity of the microchannel heat sink, and conduct the optimization of the New DL-MCHS. The heat transfer and friction characteristics of the novel DL-MCHS are studied by numerical simulation. We compare the heat transfer performance the new DL-MCHS with the traditional TDL-MCHS (the DL-MCHS with truncated top channels λ = 0.38). The results prove the effectiveness of the improved design by FLUENT simulation. When the inlet velocity is kept constant and coolant is water, the heat transfer performance of the New DL-MCHS is higher than that of TDL-MCHS leading to an increase of the temperature uniformity. In order to achieving the best overall heat transfer performance, an optimization of New DL-MCHS is performed by GA (genetic algorithm).","PeriodicalId":331854,"journal":{"name":"ASME 2019 6th International Conference on Micro/Nanoscale Heat and Mass Transfer","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129976474","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":"Molecular Dynamics Simulation of Diffusion and Aggregation Behavior of Helium in Tungsten Bulk Materials","authors":"Jiapei Zhang, Wei Li, Zhangcan Yang, Yingzhao He","doi":"10.1115/mnhmt2019-3947","DOIUrl":"https://doi.org/10.1115/mnhmt2019-3947","url":null,"abstract":"\u0000 Controlled thermonuclear fusion is a promising project. If it can be realized, it will certainly replace fossil fuels and solve the problem of energy exhaustion facing humanity. The fusion reaction fuel is a light core, which can be extracted from sea water. The source is very rich, and the fusion reaction of hydrogen and its isotopes is not radioactive, so the fusion energy can be efficient, cheap and clean.\u0000 At present, the realization of this technology still faces many difficult problems that have not been overcome. The Tokamak device is the most promising device for realizing the controlled thermonuclear fusion. It utilizes a toroidal magnetic field to confine the high temperature plasma. Among them, the choice of plasma-facing materials is the key factor that determines whether or not controlled nuclear fusion can be achieved.\u0000 For the time being, tungsten is the preferred plasma-facing material. In the case of fusion, tungsten is exposed to extreme conditions such as high temperature and strong radiation, and a large number of defects are generated inside. In this thesis, the molecular dynamics software LAMMPS was used to study one of the defects, interstitial atoms, and the interaction of helium atoms to understand the diffusion and aggregation behavior of helium and the evolution of defects in tungsten. The following aspects are mainly studied: one is the calculation of the binding energy of an interstitial atom and helium atoms, the other is the study of the interstitial and helium atoms’ space configurations, and the third is comparing trap mutation in defective tungsten materials with trap mutation in tungsten materials without defects, and the fourth is the recording of the displacement of the helium atoms and the interstitial atom at temperature control.\u0000 The study found that the presence of the interstitial atom will indeed affect the aggregation and diffusion of helium atoms, which will trap the movement of helium atoms and cause the helium atoms to gather near the interstitial atoms and form small clusters of helium. As the cluster grows larger, trap mutations occur like a defect-free tungsten block.","PeriodicalId":331854,"journal":{"name":"ASME 2019 6th International Conference on Micro/Nanoscale Heat and Mass Transfer","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116999529","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 Novel Thermal Solution for Electronics: Alumina Flat-Plate Oscillating Heat Pipe","authors":"Bohan Tian, Hongbin Ma, Yang Deming, Jiu-Jun Xu, Wang Zhiyong, N. Zhao","doi":"10.1115/mnhmt2019-3936","DOIUrl":"https://doi.org/10.1115/mnhmt2019-3936","url":null,"abstract":"\u0000 The heat flux in electronics requires the thermal management of printed circuit boards (PCBs) using two-phase cooling methods. In this study, an integrated ceramic heat transfer device, the alumina flat-plate oscillating heat pipe, is developed. The device was fabricated by pressing and sintering procedures, and the inner serpentine channels were simultaneously formed during sintering without brazing or separated caps. This novel manufacturing process simplifies the fabrication of the macrochannels inside ceramic devices and provides a new method for fabricating ceramic two-phase cooling devices. This paper presents an analysis of the internal channel’s formation mechanism and illustrates the major factors of densification. Micro-computed tomography (Micro-CT) scanning was adopted to assess the macrostructure, and SEM was used to characterize the microstructure of the alumina OHP. Water was charged inside the device as the working fluid. The effects of the power input, orientation, operating temperature and filling ratio on the heat transfer performance were investigated. The experimental results show that the alumina OHP has a high heat transport capability. When the OHP structure is embedded inside the alumina and charged with water, the thermal resistance can be reduced by 97%.","PeriodicalId":331854,"journal":{"name":"ASME 2019 6th International Conference on Micro/Nanoscale Heat and Mass Transfer","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121058928","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":"Experimental Study of Saturated Flow Boiling in Vertical Narrow Microchannel","authors":"Yuhao Lin, Kan Zhou, Junye Li, Wei Li, Hua-Yun Zhu, Zhengjiang Zhang, Jincai Du","doi":"10.1115/mnhmt2019-3935","DOIUrl":"https://doi.org/10.1115/mnhmt2019-3935","url":null,"abstract":"\u0000 An experimental study of saturated flow boiling in a high-aspect-ratio one-side-heating rectangular microchannel is conducted with deionized water as the working fluid. The bottom surface of the microchannel is constructed of two different material, one is the untreated hydrophilic silicon wafer with a contact angle of 65° ± 3°, the other is the super-hydrophilic silicon wafer deposited with a thin film of 100-nm-thickness silicon dioxide through PECVD with a contact angle less than 5°. The heat transfer characteristics of saturated flow boiling in the microchannel is studied and the flow pattern is photographed with a high speed camera. It is found that the heat transfer mechanism is dominated by convective evaporation, the heat flux transfers through the conduction and convection in the thin liquid film and evaporation at the interface between the vapor and liquid. The thinner the liquid film, the greater the heat transfer coefficient. The local dryout phenomenon is observed on the untreated hydrophilic surface while the super-hydrophilic surface can restrict the occurrence of local dryout phenomenon. This study proposes the modified Li (2010) correlation as a formula for calculating the heat transfer coefficient.","PeriodicalId":331854,"journal":{"name":"ASME 2019 6th International Conference on Micro/Nanoscale Heat and Mass Transfer","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121414960","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 Start-Up Performance of Pulsating Heat Pipe With Communicating Pipe at Different Inclination Angles","authors":"F. Shang, Fan Shilong, Jianhong Liu","doi":"10.1115/mnhmt2019-4015","DOIUrl":"https://doi.org/10.1115/mnhmt2019-4015","url":null,"abstract":"\u0000 The pulsating heat pipe (PHP) is a passive cooling device, which has the advantages of simple structure, high heat transfer performance and low production cost. The complex vapor-liquid phase change occurs in the in the initial stage of PHP. In this work, we explore the start-up performance of PHP at different inclination angles and the experiment shows that start-up performance is respectively different when the angles are 0°, 45°, 90°, 135° and 180°. Since the gravitational auxiliary function, the working fluid in the communicating pipe which takes longer time to vaporize change phase earlier than that in PHP’s loop when the angles are 0° and 45°. Nevertheless, when the angle is 90°, the phase change of working fluid in communicating pipe and in the loop occurs at the same time. Meanwhile, the oscillating mode affects the stability of the starting and heat transfer performance of the PHP.","PeriodicalId":331854,"journal":{"name":"ASME 2019 6th International Conference on Micro/Nanoscale Heat and Mass Transfer","volume":"18 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114121108","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":"Near-Field Radiative Heat Transfer Between Mie Resonance-Based Metamaterials Made of Coated Nonmagnetic Particles","authors":"Lu Lu, Jinlin Song, K. Zhou, Q. Cheng","doi":"10.1115/mnhmt2019-3998","DOIUrl":"https://doi.org/10.1115/mnhmt2019-3998","url":null,"abstract":"\u0000 Near-field radiative heat transfer between Mie resonance-based metamaterials composed of SiC/d-Si (silicon carbide and doped silicon) core/shell particles immersed in aligned nematic liquid crystals are numerically investigated. The metamaterials composed of core/shell particles exhibit superior performances of enhanced heat transfer and obvious modulation effect when compared to that without shell. The underlying mechanism can be explained that the excitation of Fröhlich mode and epsilon-near-zero (ENZ) resonances both contribute to the total heat flux. Modulation of near-field radiative heat transfer can be realized with the host material of aligned nematic liquid crystals. The largest modulation ratio could be achieved as high as 0.45 for metamaterials composed of core/shell SiC/d-Si particles, and the corresponding heat flux is higher than other similar materials such as LiTaO3/GaSb and Ge/LiTaO3. While with the same volume filling fraction, the modulation ratio of that composed of SiC particles is only 0.2. We show that the core/shell nanoparticles dispersed liquid crystals (NDLCs) have a great potential in enhancing the near-field radiative heat transfer in both the p and s polarizations with the radii of 0.65 μm, and Mie-metamaterials are shown for the first time to modulate heat flux within sub-milliseconds.","PeriodicalId":331854,"journal":{"name":"ASME 2019 6th International Conference on Micro/Nanoscale Heat and Mass Transfer","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116937853","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 and Experimental Investigation of Boiling Heat Transfer for Subcooled Water Flowing in a Small-Diameter Tube","authors":"M. Shibahara, Qiusheng Liu, K. Hata, K. Fukuda","doi":"10.1115/mnhmt2019-4163","DOIUrl":"https://doi.org/10.1115/mnhmt2019-4163","url":null,"abstract":"\u0000 Numerical simulation of boiling heat transfer for subcooled water flowing in a small-diameter tube was conducted using the commercial computational fluid dynamics (CFD) code, PHOENICS ver. 2013. A small-diameter tube (d = 1.0–2.0 mm) was modeled in the simulation. A uniform heat flux with an exponential function was given at the inner tube wall as the boundary conditions. The inner wall boundary condition was set to a non-slip. The inlet temperature ranged from 302 to 312 K. The flow velocities of d = 1.0 mm and d = 2.0 mm are 9.29 m/s and 2.34 m/s, respectively. The transient analysis was carried out from the non-boiling region since the heat flux increased with time in the author’s experiments. The governing equations including the energy equation were discretized using the finite volume method in the PHOENICS code. The SIMPLE method was applied for the numerical simulation. For modeling boiling phenomena in the tube, the Eulerian-Eulerian two-fluid model was adopted using the interphase slip algorithm of PHOENICS code. In the experiment, a platinum tube was used as the experimental tube (d = 1.0–2.0 mm) to conduct joule heating by direct current. The distilled and deionized water was pressured by the pressurizer. The heat generation rate of the tube was controlled with the exponential function to obtain the transient heat transfer characteristics from the non-boiling region. The surface superheat increased as the heat flux increased in the experiment. The numerical simulation predicted the experimental data well. When the heat flux of the experiment was reached to the CHF point, the predicted value of heat transfer coefficient was approximately 3.5 % lower than that of the experiment.","PeriodicalId":331854,"journal":{"name":"ASME 2019 6th International Conference on Micro/Nanoscale Heat and Mass Transfer","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124900545","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}