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Experimental study and numerical simulation of gas-particle flows with radial bias combustion and centrally fuel rich swirl burners 被引量:1
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作者 李争起 周珏 +2 位作者 陈智超 孙锐 秦裕琨 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2008年第1期1-8,共8页
Numerical simulation is applied to gas-particle flows of the primary and the secondary air ducts and burner region, and of two kinds of swirl burners. The modeling results of Radial Bias Combustion (RBC) burner well a... Numerical simulation is applied to gas-particle flows of the primary and the secondary air ducts and burner region, and of two kinds of swirl burners. The modeling results of Radial Bias Combustion (RBC) burner well agreed with the data from the three-dimensional Phase-Doppler anemometry (PDA) experiment by Li, et al. The modeling test conducted in a 1025 t/h boiler was to study the quality of aerodynamics for a Central Fuel Rich (CFR) burner, and the Internal Recirculation Zone (IRZ) was measured. In addition, gas-particle flows with a CFR burner were investigated by numerical simulation, whose results accorded with the test data fundamentally. By analyzing the distribution of gas velocity and trajectories of particles respectively, it is found that the primary air’s rigidity of CFR burner is stronger than that of RBC burner, and the primary air mixes with the secondary air later. Furthermore, high concentration region of pulverized coal exists in the burner’s central zone whose atmosphere is reduced, and trajectories of particles in IRZ of CFR burner are longer than that of RBC burner. They are favorable to coal’s ignition and the reduction of NOx emission. 展开更多
关键词 锅炉制造 数字模拟 燃烧嘴 气流
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Direct numerical simulation of Open Von Kármán Swirling Flow 被引量:2
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作者 XING Tao 《Journal of Hydrodynamics》 SCIE EI CSCD 2014年第2期165-177,共13页
Direct numerical simulations are used to investigate the Open Von Kfirmfin Swirling Flow, a new type of unsteady three-dimensional flow that is formed between two counter-rotating coaxial disks with an axial extractio... Direct numerical simulations are used to investigate the Open Von Kfirmfin Swirling Flow, a new type of unsteady three-dimensional flow that is formed between two counter-rotating coaxial disks with an axial extraction enclosed by a cylinder chamber. Solution verification shows that monotonic convergence is achieved on three systematically refined grids for average pressure at the disk periphery with a small grid uncertainty at 3.5%. Effects of the rotational speeds and flow rates on the flow field are examined. When the disks are rotating at the lowest speed, +100 RPM, only circular vortices are formed regardless of the flow rates. When the disks are rotating at +300 RPM and +500 RPM, negative spiral vortex network is formed. The radial counterflow concept for such spiral vortex network is verified by examining various horizontal cuts and radial velocity component, which show radial outflows in two bands near the two disks and radial inflow in one band between them. Overall, the flow is similar to the Stewartson type flow but with significant differences for all three velocity components due to the axial suction at the upper disk center and gap between the disk periphery and chamber wall. 展开更多
关键词 direct numerical simulation Open Von Kfirmfin flow swirling radial counterflow
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Numerical simulation of the effect of upstream swirling flow on swirl meter performance 被引量:4
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作者 CHEN Desheng CUI Baoling ZHU Zuchao 《Journal of Thermal Science》 SCIE EI CAS CSCD 2018年第2期117-124,共8页
Flow measurement is important in the fluid process and transmission system. For the need of accuracy measurement of fluid, stable flow is acquired. However, the elbows and devices as valves and rotary machines may pro... Flow measurement is important in the fluid process and transmission system. For the need of accuracy measurement of fluid, stable flow is acquired. However, the elbows and devices as valves and rotary machines may produce swirling flow in the natural gas pipeline networks system and many other industry fields. In order to reveal the influence of upstream swirling flow on internal flow fields and the metrological characteristics, numerical simulations are carried out on the swirl meter. Using RNG k-ε turbulent model and SIMPLE algorithm, the flow field is numerically simulated under swirling flows generated from co-swirl and counter-swirl flow. Simulation results show fluctuation is enhanced or weakened depending on the rotating direction of swirling flow. A counter-swirl flow increases the entropy production rate at the inlet and outlet of the swirler, the junction region between throat and divergent section, and then the pressure loss is increased. The vortex precession dominates the static pressure distributions on the solid walls and in the channel, especially at the end region of the throat. 展开更多
关键词 流动测量 数字模拟 上游 性能 网络系统 天然气管道 旋转机器 内部流动
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Numerical simulation of strongly swirling turbulent flows in a liquid-liquid hydrocyclone using the Reynolds stress transport equation model 被引量:1
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作者 陆耀军 周力行 沈熊 《Science China(Technological Sciences)》 SCIE EI CAS 2000年第1期86-96,共11页
The Reynolds stress transport equation model (DSM) is used to predict the strongly swirling turbulent flows in a liquid-liquid hydrocyclone, and the predictions are compared with LDV measurements . Predictions properl... The Reynolds stress transport equation model (DSM) is used to predict the strongly swirling turbulent flows in a liquid-liquid hydrocyclone, and the predictions are compared with LDV measurements . Predictions properly give the flow behavior observed in experiments, such as the Rankine-vortex structure and double peaks near the inlet region in tangential velocity profile, the downward flow near the wall and upward flow near the core in axial velocity profiles. In the inlet or upstream region of the hydrocyclone, the reverse flow near the axis is well predicted, but in the region with smaller cone angle and cylindrical section, there are some discrepancies between the model predictions and the LDV measurements. Predictions show that the pressure is small in the near-axis region and increases to the maximum near the wall. Both predictions and measurements indicate that the turbulence in hydrocy-clones is inhomogeneous and anisotropic. 展开更多
关键词 STRONGLY swirling flowS numerical simulation hydrocydone.
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Numerical Simulation of Swirling Gas-solid Two Phase Flow through a Pipe Expansion
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作者 JinHanhui XiaJun 《Journal of Thermal Science》 SCIE EI CAS CSCD 2001年第1期38-45,共8页
A κ- ε -kp muiti-fluid model is stated and adopted to simulate swirling gas-solid two phase flow. A particle-laden flow from a center tube and a swirling air stream from the coaxial annular enter the test section. A... A κ- ε -kp muiti-fluid model is stated and adopted to simulate swirling gas-solid two phase flow. A particle-laden flow from a center tube and a swirling air stream from the coaxial annular enter the test section. A series of numerical simulations of the two-phase flow are performed based on 30 μm, 45 μ m, 60 μ m diameter particles respectively. The results fit well with published experimental data. 展开更多
关键词 气-固二相流 通过管道 湍流模拟
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Experimental and Numerical Investigation of Swirling Flow on Triple Elbow Pipe Layout 被引量:2
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作者 Hideharu Takahashi San Shwin +2 位作者 Ari Hamdani Nobuyuki Fujisawa Hiroshige Kikura 《Journal of Flow Control, Measurement & Visualization》 2020年第2期45-62,共18页
The secondary flow downstream of a triple elbow layout was studied experimentally and numerically to visualize the flow behavior under swirling inlet flow conditions. The inlet swirling condition was generated by a sw... The secondary flow downstream of a triple elbow layout was studied experimentally and numerically to visualize the flow behavior under swirling inlet flow conditions. The inlet swirling condition was generated by a swirl generator, consisting of a rotary pipe and honeycomb assembly. The experiments were carried out in turbulent water flow condition at Reynolds number Re = 1 × 104 and inlet swirl intensity S = 1. Ultrasonic measurements were taken at four locations downstream of the third elbow. The two-dimensional velocity field of the flow field was measured using the phased array ultrasonic velocity profiler technique to evaluate the flow field with separation. Furthermore, a numerical simulation was performed and its results were compared with the experimental data. The numerical result was obtained by solving three-dimensional, Reynolds-averaged Navier-Stokes equations with the renormalization group k-ε turbulence model. The experimental results confirmed that the swirling flow condition modified the size of the separation region downstream of the third elbow. A qualitative comparison between the experimental and CFD simulation results of the averaged velocity field downstream of the third elbow showed similar tendency on reverse flow. 展开更多
关键词 swirling flow TRIPLE ELBOW ULTRASOUND Phased Array Sensor VELOCITY PROFILE CFD numerical simulation
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Numerical simulation of flow in swirl injector for power-law fluid 被引量:1
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作者 WANG Feng FU Qing-fei YANG Li-jun 《航空动力学报》 EI CAS CSCD 北大核心 2012年第4期890-899,共10页
In order to investigate the flow characteristics of swirl injectors for gelled propellants,which actually behaved as non-Newtonian power-law fluid,a swirl axisymmetric model was established to solve Navier-Stokes equa... In order to investigate the flow characteristics of swirl injectors for gelled propellants,which actually behaved as non-Newtonian power-law fluid,a swirl axisymmetric model was established to solve Navier-Stokes equations and VOF(volume of fluid) equation,and the power-law constitutive equation was used to describe the rheology characteristics of the gelled propellants.The film thickness and velocity distribution in the swirl injector under different flow conditions were studied numerically.The simulation results show that the increased geometry characteristic parameter of the swirl injector contributes to the decrease of liquid film thickness.The liquid film thickness is almost independent of the pressure drop.The rheologic parameters have great influences on the inner flow of swirl injector: by increasing the fluid consistency index K and power index n,both the axial and the swirl velocities decrease dramatically;higher fluid consistency index K and power index n make the liquid film thickness increase.When the viscosity is large enough,the air core in the injector would vanish. 展开更多
关键词 numerical simulation gelled propellants power-law fluid swirl injector inner flow
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Numerical Simulation of Gas-particle Flows with Different Swirl Numbers in a Swirl Burner 被引量:1
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作者 罗纲 李荣先 周力行 《Tsinghua Science and Technology》 EI CAS 2000年第1期96-99,共4页
Swirl burner design was optimized by simulating swirl gas\|particle flows with different swirl numbers at the exit of a small\|scale swirl burner for pulverized\|coal furnaces using the k\|ε\|k p model. The pred... Swirl burner design was optimized by simulating swirl gas\|particle flows with different swirl numbers at the exit of a small\|scale swirl burner for pulverized\|coal furnaces using the k\|ε\|k p model. The predicted two\|phase time\|averaged velocities and particle concentration distributions for several different cases were compared to improve the design. The effect of the swirl number on the two\|phase velocities and particle concentration was investigated. The results give the two\|phase axial and tangential time\|averaged and fluctuation velocities and particle concentrations, showing that large recirculation zones of gas and particles forms in the near\|axis region of the burner exit, but the particle concentration in the recirculating zone is very low. 展开更多
关键词 gas\|particle flow numerical simulation swirl burner
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Numerical calculation of flow and heat transfer process in the new-type external combustion swirl-flowing hot stove
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作者 ShuchenZhang HongzhiGuo +3 位作者 XiangjunLiu ZhangpingCai XianchengGao SidongXu 《Journal of University of Science and Technology Beijing》 CSCD 2003年第5期31-34,共4页
It is clarified that the important method to improve the blast temperature ofthe small and the middle blast furnaces whose production is about two-thirds of total sum of Chinafrom 1000℃ to 1250-1300℃ is to preheat b... It is clarified that the important method to improve the blast temperature ofthe small and the middle blast furnaces whose production is about two-thirds of total sum of Chinafrom 1000℃ to 1250-1300℃ is to preheat both their combustion-supporting air and coal gas. The airtemperature of blast furnaces can be reached to 1250-1300℃ by burning single blast furnace coal gasif high speed burner is applied to blast furnaces and new-type external combustion swirl-flowinghot stove is used to preheat their combustion-supporting air. The computational results of the flowand heat transfer processions in the hot stove prove that the surface of the bed of the thermalstorage balls there have not eccentric flow and the flow field and temperature field distribution iseven. The computational results of the blast temperature distribution are similar to thosedetermination experiment data. The numerical results also provide references for developing anddesigning the new-type external combustion swirl-flowing hot stoves. 展开更多
关键词 new-type external combustion swirl-flowing hot stove flow field temperaturefield numerical calculation
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基于FLOW-3D软件的旋流起旋室水力特性数值模拟 被引量:5
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作者 丁晓唐 徐大雷 朱峰 《三峡大学学报(自然科学版)》 CAS 2016年第3期11-14,共4页
文章采用FLOW-3D软件,通过RNGk-ε模型和volume of fluid(VOF)方法相结合,实现了竖井水平旋流泄洪洞水力特性的三维水流流场数值模拟;对开敞式进水口轴线与旋流洞轴线交角不同时起旋室的压强分布、旋流角和紊动能等水力特性进行了对比... 文章采用FLOW-3D软件,通过RNGk-ε模型和volume of fluid(VOF)方法相结合,实现了竖井水平旋流泄洪洞水力特性的三维水流流场数值模拟;对开敞式进水口轴线与旋流洞轴线交角不同时起旋室的压强分布、旋流角和紊动能等水力特性进行了对比分析研究,数值模拟能够客观地反映起旋室旋流的流场特性,成果可为旋流溢洪道的研究应用提供参考. 展开更多
关键词 VOF方法 K-Ε紊流模型 水平旋流 紊动能 三维数值模拟
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旋流排沙渠道中旋转水流的排沙效果研究
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作者 南军虎 马康宁 +3 位作者 汪超群 李伟 陶然 代江龙 《工程科学与技术》 EI CAS CSCD 北大核心 2024年第3期170-178,共9页
旋流排沙渠道是基于旋转水流强挟带能力的特点提出的一种渠道水沙分离新技术,为了明晰其水沙特性,在试验研究的基础上,采用Realizable k-ε模型、VOF法及离散相模型,对旋流排沙渠道内的水沙两相流特性进行了数值模拟,通过与模型试验成... 旋流排沙渠道是基于旋转水流强挟带能力的特点提出的一种渠道水沙分离新技术,为了明晰其水沙特性,在试验研究的基础上,采用Realizable k-ε模型、VOF法及离散相模型,对旋流排沙渠道内的水沙两相流特性进行了数值模拟,通过与模型试验成果的对比确定了不同粒径泥沙的球度,研究了持续来沙条件下旋流排沙渠道的排沙效果,分析了渠道和排沙洞内泥沙的分布规律。结果表明:不同粒径泥沙的球度介于0.2~1.0之间时,在渠道顶部局部来沙条件下旋流排沙渠道对粒径为(0.075,3.000]mm泥沙的计算截沙率与试验值吻合良好,二者的相对误差仅为3.5%,误差主要来源于(0.075,0.160]mm的极细颗粒泥沙;当上游渠道水流进口来沙质量流量为60 g/s时,渠底高含沙水流由起旋室的分流,渠道含沙量迅速降低,起旋室前部和后部渠底水流含沙量分别为44.00 kg/m^(3)和0.07 kg/m^(3);排沙洞内的旋转水流对泥沙的挟带作用明显,在强离心作用下泥沙主要分布在排沙洞近壁面,最大泥沙含量约为200.00 kg/m^(3);在持续来沙条件下旋流排沙渠道对粒径为(0.075,3.000]mm泥沙的截沙率为95.98%,仅少量极细泥沙以悬移质形式进入下游渠道,渠道和排沙洞内无大量的泥沙淤积,表明旋流排沙渠道是一种可实现高效且连续排沙的水沙分离技术。本成果可为旋流排沙渠道在工程中的应用和水沙特性的研究提供有益参考。 展开更多
关键词 旋流排沙渠道 水沙特性 数值模拟 离散相模型 截沙率
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体型参数对旋流排沙渠道水沙特性的影响
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作者 南军虎 代江龙 +2 位作者 李伟 汪超群 马康宁 《水利水电科技进展》 CSCD 北大核心 2024年第3期64-72,共9页
为明确关键体型参数对渠道和排沙洞内水沙特性的影响,在模型试验研究的基础上开展了旋流排沙渠道的水沙两相流数值模拟。结果表明:起旋室高度对截沙率影响较为显著,最大相差5.41%;排沙洞直径、倾角和起旋室出口宽度对分流比影响显著,最... 为明确关键体型参数对渠道和排沙洞内水沙特性的影响,在模型试验研究的基础上开展了旋流排沙渠道的水沙两相流数值模拟。结果表明:起旋室高度对截沙率影响较为显著,最大相差5.41%;排沙洞直径、倾角和起旋室出口宽度对分流比影响显著,最大相差8.13%,增大倾角后改善了原排沙洞封闭端因壁面条件影响而产生的泥沙淤积;起旋室出口宽度对渠道内水沙特性基本无影响;不同体型下旋流排沙渠道均可高效、持续排沙,截沙率均大于90%,经过起旋室后,高含沙水流从排沙洞流出,下游渠道含沙量急剧减小。 展开更多
关键词 旋流排沙渠道 体型参数 水沙特性 截沙率 数值模拟
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高水头旋流阻塞复合内消能工水力特性研究
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作者 王立杰 李奇龙 +1 位作者 张鹏君 李江波 《水资源与水工程学报》 CSCD 北大核心 2024年第2期115-121,共7页
旋流阻塞复合内消能工是适用于高坝泄洪消能的一种新型消能工,为了分析其在超高作用水头下的泄洪消能适用情况,采用模型试验与数值模拟相结合的方法,对200 m作用水头条件下该消能工的水力特性进行了研究。结果表明:泄流量为1547 m^(3)/s... 旋流阻塞复合内消能工是适用于高坝泄洪消能的一种新型消能工,为了分析其在超高作用水头下的泄洪消能适用情况,采用模型试验与数值模拟相结合的方法,对200 m作用水头条件下该消能工的水力特性进行了研究。结果表明:泄流量为1547 m^(3)/s,略大于设计值,满足泄流要求;洞内形成了稳定的空腔旋流,旋流洞段空腔直径约6~7 m,旋流角约60°,壁面压强约110×9.8 kPa,最大点流速约45 m/s;起旋器与旋流洞段为0.050~0.274 Hz的低频脉动,且水流空化数均大于1.2,运行安全;阻塞扩散段末端最小瞬时负压为-3.81×9.8 kPa,且水流空化数较小,但水流掺气率较高,有利于减免发生空蚀;阻塞扩散段末脉动优势频率为46.99 Hz;总消能率达82.1%,消能率高。研究成果可为该复合消能工在高水头下的泄洪消能应用提供参考。 展开更多
关键词 旋流阻塞复合内消能工 阻塞 空腔旋流 模型试验 数值模拟 水力特性
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某双油路离心式喷嘴雾化性能分析
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作者 彭真臻 侯力 +1 位作者 游云霞 盛鑫 《机械设计与制造》 北大核心 2024年第3期57-61,共5页
燃油喷嘴的雾化对于解决航空发动机燃烧室问题是至关重要的,为探究某双油路离心式喷嘴的雾化性能,运用两相界面追踪流体体积(Volume of Fluid,简称VOF)方法对该喷嘴的内外部流场进行数值仿真。以双油路离心喷嘴的雾化锥角、质量流率以... 燃油喷嘴的雾化对于解决航空发动机燃烧室问题是至关重要的,为探究某双油路离心式喷嘴的雾化性能,运用两相界面追踪流体体积(Volume of Fluid,简称VOF)方法对该喷嘴的内外部流场进行数值仿真。以双油路离心喷嘴的雾化锥角、质量流率以及液膜厚度作为雾化性能指标,分别模拟出主油路单独供油、副油路单独供油以及主副油路同时供油三种不同工作模式在不同压差条件下喷嘴燃油流动的稳态情况,获得双油路离心喷嘴的雾化性能指标并对其影响规律进行研究。结果显示:数值仿真能较好地模拟出喷嘴的雾化特性,随着压差增大,扩口式主油路单独工作时的雾化锥角减小,平口式副油路单独工作时的雾化锥角增大。当主、副油路同时工作时,雾化锥角随压差的增大而增大且始终处于单路单独工作时的雾化锥角之间;质量流率随着压差的增大而增大且增幅逐渐减缓;液膜厚度在低压区随压差的增大而迅速减小,随后趋于稳定。 展开更多
关键词 双油路离心式喷嘴 数值仿真 雾化性能 雾化锥角 质量流率 液膜厚度
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Structural Optimization of Electromagnetic Swirling Flow in Nozzle of Slab Continuous Casting 被引量:2
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作者 Xiao-Wei Zhu De-Wei Li +2 位作者 Chun-Lei Wu Katsukiyo Marukawa Qiang Wang 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2018年第12期1317-1326,共10页
During the slab continuous casting process, the flow field of molten steel in the mold plays a decisive role in the quality ofthe slab. In this paper, electromagnetic swirling flow in nozzle technology is proposed to ... During the slab continuous casting process, the flow field of molten steel in the mold plays a decisive role in the quality ofthe slab. In this paper, electromagnetic swirling flow in nozzle technology is proposed to control the flow field in mold.This technology can drive molten steel to rotate inside the submerged entry nozzle by electromagnetic force, therebycontrolling the flow field. This research shows that it can reduce the impact of molten steel on the bottom of nozzle andpartly reduce the negative pressure at the upper part of nozzle outlet which is even eliminated by optimizing the structureand angle of nozzle. The area of heat flux of the mold wall becomes larger, and the crest value of heat flux gets lower thanthat without swirling in nozzle and any nozzle optimization. The meniscus fluctuates smoothly, and the flow velocity at thetop surface is within a reasonable range. The temperature field distribution in the mold is uniform which was beneficial tothe growth of equiaxed crystal and decreased element segregation. 展开更多
关键词 Continuous casting Submerged entry nozzle Electromagnetic swirling flow SLAB numerical simulation
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旋流式微通道热沉传热特性研究
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作者 李昌辉 刘洪涛 《内燃机与配件》 2024年第2期10-12,共3页
随着微电子设备高度集成化和小型化发展,电子器件发热量增加,其热管理问题是目前的研究热点。本文针对旋流式微通道热沉传热和流动特性开展了数值模拟的研究,讨论了冷却剂流量和均热板材料导热系数的影响。研究结果表明,与常规微通道不... 随着微电子设备高度集成化和小型化发展,电子器件发热量增加,其热管理问题是目前的研究热点。本文针对旋流式微通道热沉传热和流动特性开展了数值模拟的研究,讨论了冷却剂流量和均热板材料导热系数的影响。研究结果表明,与常规微通道不同,随冷却剂流量增加,旋流式微通道热沉内冷却剂旋律程度增强,流程增加,导致高温向热沉中心出口位置迁移,高低温差降低。热沉底部均热材料导热系数增加时,加热面上方径向和周向导热增强,导致加热面平均温度和高低温差降低。 展开更多
关键词 微通道热沉 旋流 数值模拟 温度分布
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Fundamental Study on Continuous Casting Process With Swirling Flow by Electromagnetic Force 被引量:1
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作者 SU Zhi-jian LI De-wei +2 位作者 CHEN-Jin MARUKAWA Katsukiyo HE Ji-cheng 《Journal of Iron and Steel Research(International)》 SCIE EI CAS CSCD 2012年第S2期879-883,共5页
Swirling flow in a submerged entry nozzle is effective on improving quality of casting block and casting speed in continuous casting of steel.A new method for swirling flow generation in the nozzle has been proposed b... Swirling flow in a submerged entry nozzle is effective on improving quality of casting block and casting speed in continuous casting of steel.A new method for swirling flow generation in the nozzle has been proposed by the authors,that is a rotating electromagnetic field is set up around a submerged entry nozzle(SEN)to induce swirling flow in it by Lorentz force.In this study,the magnetic field in molten steel in the submerged entry nozzle,the flow and temperature field in the SEN and mold in round,square billet and slab continuous casting process of steel are numerically studied.The model experiment of electromagnetic swirling continuous casting is also conducted with low melting point alloy.The commercial test for slab is undergoing.Results by numerical simulation and experiment show that the swirling flow by the optimum designed electromagnetic swirling generator can not only improve the distribution of flow and temperature in mold but also achieve the same effects generated by the swirling blade process. And,more effects on continuous casting process can be expected after this electromagnetic swirling process is optimized. 展开更多
关键词 continuous casting process submerged entry nozzle swirling flow rotating magnetic field numerical simulation
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CFD-PBM框架下旋流式微泡发生器气泡动力学行为
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作者 邢继远 《化学工程》 CAS CSCD 北大核心 2024年第3期59-65,共7页
为探究旋流式微泡发生器气泡直径变化规律以及气泡动力学行为,采用欧拉-欧拉非均质气液二相模型求解流动参数,并耦合PBM(群体平衡模型)求解直径在1—1000μm内的14个直径气泡数密度变化,利用Luo破碎-Liao合并组合模型对旋流式微泡发生... 为探究旋流式微泡发生器气泡直径变化规律以及气泡动力学行为,采用欧拉-欧拉非均质气液二相模型求解流动参数,并耦合PBM(群体平衡模型)求解直径在1—1000μm内的14个直径气泡数密度变化,利用Luo破碎-Liao合并组合模型对旋流式微泡发生器内部的气泡破碎合并行为进行分析。模拟计算结果与实验相近,说明CFD-PBM可以用来求解旋流式微泡发生器内部的气泡直径变化。由此可知,模拟条件下,气泡破碎频率对于液体流速变化更加敏感,气泡合并频率对于当地含气率变化更为敏感;气相主要分布在旋流式微泡发生器的中轴线附近处,并且沿着中轴线可见细长分布类似龙卷风形状的大气泡区;液体流量增加及出口直径的减小均会促进出口气泡直径的减小;气泡直径对于入口气体流量的变化并不敏感,并且这种影响关系还受到出口直径的影响。 展开更多
关键词 旋流式微泡发生器 二相流 计算流体力学 数值模拟 群体平衡模型
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缩进长度对液液同轴离心喷嘴雾化过程的影响
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作者 王壮 党枭睿 +1 位作者 胡海峰 卞香港 《火箭推进》 CAS 北大核心 2024年第3期42-52,共11页
为探究缩进长度对液液同轴离心喷嘴雾化锥角的影响,中心喷嘴工质采用N_(2)O_(4),外喷嘴工质采用偏二甲肼(UDMH),通过数值仿真获得了喷嘴内部流场的细节特征以及缩进数N对喷嘴雾化锥角的影响规律。结果表明:当N<1时,喷嘴的雾化锥角呈... 为探究缩进长度对液液同轴离心喷嘴雾化锥角的影响,中心喷嘴工质采用N_(2)O_(4),外喷嘴工质采用偏二甲肼(UDMH),通过数值仿真获得了喷嘴内部流场的细节特征以及缩进数N对喷嘴雾化锥角的影响规律。结果表明:当N<1时,喷嘴的雾化锥角呈现先增后减的趋势;当N>1时,喷嘴的雾化锥角略微增大;当N=0时,UDMH与N_(2)O_(4)液膜之间会形成低压区,使得UDMH液膜张角减小,N_(2)O_(4)液膜张角变大,并在液膜末端贴合在一起,最终雾化锥角为外喷嘴与中心喷嘴雾化锥角的中间值;当N>0.85时,UDMH与N_(2)O_(4)会在缩进室内部发生明显的掺混,液膜变形程度加剧;当N>1.27时,缩进室会对内部混合流体起到整流作用,从而使其雾化距离增加。 展开更多
关键词 缩进数 液液同轴离心喷嘴 雾化锥角 流场结构 数值模拟
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Algebraic Stress Model with RNG ε-Equation for Simulating Confined Strongly Swirling Turbulent Flows 被引量:8
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作者 XuJiangrong YaoQiang 《Journal of Thermal Science》 SCIE EI CAS CSCD 2001年第1期14-19,共6页
Strongly swirl flow simulation are still under deve1oping. In this paper, ε equation based on the Renormalization. Group theory is used into algebraic stress model. Standard κ-ε model, algebraic stress model by Jia... Strongly swirl flow simulation are still under deve1oping. In this paper, ε equation based on the Renormalization. Group theory is used into algebraic stress model. Standard κ-ε model, algebraic stress model by Jiang Zhang[5]. and present model (RNG-ASM) are applied simultaneously to simulating the confined strongly swirling flow. The Simulating results by RNG-ASM model are compared to the results by other two model, it is shown that the predictions by this model display reasonable agreement with experimental data, and lead to gnater improvement than Zhang’s ASM turbulence model[5]. 展开更多
关键词 湍流 重整体群法 数字模拟
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