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水煤浆气化炉激冷流程中气液两相负浮力流动的数值模拟 被引量:18
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作者 龚晓波 顾兆林 +3 位作者 林高平 冯霄 郁永章 林宗虎 《化工学报》 EI CAS CSCD 北大核心 2003年第7期930-935,共6页
综合逆压突扩流动和浮力各向异性的流场特征 ,运用颗粒群理论 ,引入Shih的Reynolds应力通用本构关系建立了可实现性应力代数模型 .在模型中引入涡扩散理论建立了扩散方程 ,解决了气液两相数值模拟中流型变化带来的复杂问题 .运用该模型... 综合逆压突扩流动和浮力各向异性的流场特征 ,运用颗粒群理论 ,引入Shih的Reynolds应力通用本构关系建立了可实现性应力代数模型 .在模型中引入涡扩散理论建立了扩散方程 ,解决了气液两相数值模拟中流型变化带来的复杂问题 .运用该模型对气化炉洗涤室内流场进行了数值预报 ,并进一步量化分析了出口动量与最大下降深度和夹层内侧出口含气率的关系 . 展开更多
关键词 气液两相流 应力代数模型 双流体模型 逆压力梯度 浮力流动 水煤浆气化
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林火上方浮力流动与火区及气象因素关系的数值模拟 被引量:1
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作者 王清安 寇晓军 《火灾科学》 CSCD 1993年第1期38-43,共6页
本文应用FAC2程序,通过数值计算的方法,模拟了森林野外火区上的浮力流动随火区参数及环境气象因素的改变而变化的情况。我们考虑的火区因素有:人口速度、人口温度、及火区尺寸,考虑的环境气象因素有:大气静力稳定度和侧风。作者较为系... 本文应用FAC2程序,通过数值计算的方法,模拟了森林野外火区上的浮力流动随火区参数及环境气象因素的改变而变化的情况。我们考虑的火区因素有:人口速度、人口温度、及火区尺寸,考虑的环境气象因素有:大气静力稳定度和侧风。作者较为系统地计算了一些算例,通过这些算例可以初步给出森林野外火中,火区上的浮力流动与火区参数及这些气象因素关系的粗略图像。 展开更多
关键词 森林火 浮力流动 数值模拟 气象
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森林野外火火区上的浮力流动与降雨的相互作用模型
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作者 王清安 寇晓军 《自然灾害学报》 CSCD 1993年第2期27-34,共8页
本文是在《森林野外火火区上的浮力流动及其与一些环境气象因素关系的数值模拟》的基础上进行的。上文求解了无降雨时的气体流动情况,本文在此基础上加入了降雨模型,形成了能体现降雨与气流相互作用的程序。本文算出了不同大小的雨滴的... 本文是在《森林野外火火区上的浮力流动及其与一些环境气象因素关系的数值模拟》的基础上进行的。上文求解了无降雨时的气体流动情况,本文在此基础上加入了降雨模型,形成了能体现降雨与气流相互作用的程序。本文算出了不同大小的雨滴的下落过程,并能估计出多大的雨滴可落入燃烧区。 展开更多
关键词 森林 野外火 浮力流动 数值模拟
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各向异性湍浮力模型的研究
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作者 阳坤 洪益平 +1 位作者 周雪漪 李玉梁 《应用数学和力学》 EI CSCD 北大核心 2000年第1期39-44,共6页
通过对隐式代数应力模型应力结构的分析,认为湍浮力流动的应力由应变和浮力作用引起,从而利用应力输运的线性近似和平衡近似提出了非线性各向异性湍浮力模型· 该模型避免了数值奇异,其可靠性通过计算和实验的对比得到了验证·
关键词 代数应力模型 浮力模型 各向异性 浮力流动
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基于CFD的安全壳内浮力驱动自然对流特性分析 被引量:2
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作者 邓豪放 王安庆 吕续舰 《核技术》 CAS CSCD 北大核心 2022年第9期75-84,共10页
在核反应堆发生严重事故时,自然对流、传热和湍流现象对安全壳内的气体流动和分布起着重要作用。为研究事故发生时安全壳内气体流动和换热现象,并分析自然对流下的温度分布。采用计算流体力学(Computational Fluid Dynamics,CFD)方法开... 在核反应堆发生严重事故时,自然对流、传热和湍流现象对安全壳内的气体流动和分布起着重要作用。为研究事故发生时安全壳内气体流动和换热现象,并分析自然对流下的温度分布。采用计算流体力学(Computational Fluid Dynamics,CFD)方法开展数值模拟研究,首先利用差异加热空腔实验数据对CFD方法分析封闭空间内自然对流换热现象的适用性进行验证,然后建立了与THAI(Thermal-hydraulics,Hydrogen,Aerosols and Iodine)-TH21实验装置相对应的几何模型,分析了实验过程中安全壳内压力变化以及达到稳定状态后装置内的流动换热特性。结果表明:本文采用的计算方法对分析安全壳内气体流动换热具有较好的适用性,模拟得到的准静态压力高于实验压力1.61%,冷壁面附近温度分布与实验数据吻合良好,热壁面附近温度分布误差在2%以内。研究有助于相关数值方法与模型的验证与开发,并可为反应堆事故发生时安全壳内气体流动及分布提供一定的参考。 展开更多
关键词 计算流体力学 安全壳 浮力驱动流动 自然对流 热辐射
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环形浅池内硅熔体中的热流体波 被引量:1
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作者 彭岚 李友荣 +2 位作者 吴双应 李明伟 曾丹苓 《计算力学学报》 EI CAS CSCD 北大核心 2006年第3期295-300,共6页
为了了解工业Czochralski炉内硅熔体表面轮型的基本特征,对环形浅池内硅熔体的热毛细-浮力对流进行了三维数值模拟,硅熔池内径为15 mm,外径为50 mm,深度为3 mm,熔池外壁被加热,内壁被冷却,底部固壁和顶部自由表面均绝热或者允许一个垂... 为了了解工业Czochralski炉内硅熔体表面轮型的基本特征,对环形浅池内硅熔体的热毛细-浮力对流进行了三维数值模拟,硅熔池内径为15 mm,外径为50 mm,深度为3 mm,熔池外壁被加热,内壁被冷却,底部固壁和顶部自由表面均绝热或者允许一个垂直方向的传热。模拟结果表明,当径向温差较小时,熔池内会产生稳定的单胞热毛细-浮力流动,随着温差的增大,流动将转变为三维振荡流动,在熔体自由表面会出现沿周向运动的轮型,小的垂直方向的热流密度(3W/cm2)对这种振荡流动没有大的影响。同时,讨论了流动和温度波动的特征,并确定了振荡流动的临界条件。 展开更多
关键词 热毛细-浮力流动 热流体波 硅熔体 数值模拟 环形池
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Numerical Study of Water and Suspended Matter Exchange Between the Yellow Sea and the East China Sea 被引量:7
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作者 庞重光 白学志 胡敦欣 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2003年第3期214-221,共8页
POM was used to study the monthly mean circulation in the Yellow Sea and East China Sea. The calculated results showed almost all major characteristics of the circulation system. The calculated circulation system and ... POM was used to study the monthly mean circulation in the Yellow Sea and East China Sea. The calculated results showed almost all major characteristics of the circulation system. The calculated circulation system and observational data were used to determine the sediment concentration, volume transport, heat flux and suspended matter flux between the Yellow Sea and the East China Sea. The conclusions obtained were that the volume and heat are transported northward through the 32°N section during each season; that in winter and autumn, total suspended matter is transported southward, and is larger in winter than in autumn. The reason is that the Yellow Sea Coastal Current is strong and always contains more suspend matter in winter and autumn. The seasonal suspended matter exchange between the Yellow Sea and the East China Sea are 0.58×10 7 tons in spring, 2.81×10 7 tons in summer, -2.60×10 7 tons in autumn and -3.40×10 7 tons in winter. Net flux of suspended matter from the Yellow Sea to the East China Sea is 2.61×10 7 tons every year. 展开更多
关键词 Yellow Sea East China Sea water exchange suspended matter flux numerical simulation
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A single-phase turbulent flow numerical simulation of a cyclonic-static micro bubble flotation column 被引量:7
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作者 Yan Xiaokang Liu Jiongtian +1 位作者 Cao Yijun Wang Lijun 《International Journal of Mining Science and Technology》 2012年第1期95-100,共6页
Improved fluid dynamics can enhance the separation efficiency of flotation methods. A Computational Fluid Dynamics simulation using FLUENT was performed to model the fluid environment of a cyclonic-sta- tic micro bubb... Improved fluid dynamics can enhance the separation efficiency of flotation methods. A Computational Fluid Dynamics simulation using FLUENT was performed to model the fluid environment of a cyclonic-sta- tic micro bubble flotation column. The simulation results visually show the interior flow and illustrate mix- ing of the different flows within the apparatus. An analysis of the distribution in velocity and vorticity was used to analyze the separation mechanism and the synergism of the component parts and to strengthen the design of each unit. The conclusions are that axial back mixing and vortexes still exist in the separation unit even in the presence of packing media. The inverted cone structure near the tangential inlet (cone 1 ) within the cyclonic unit is the main reason for this. The cone 1 structure enhances swirling and focuses energy within the inner area of the cone where there are abundant bubbles. As a result slowly floating minerals are forcibly recovered and railings are effectively separated within this unit. However, cone 1 also reduces the vorticity downstream from it, which reduces the efficiency of railings separation within this part. Therefore, the design of cone 1 should be based on the principles of lessening disturbances to the column unit while strengthening the separation effect of the cyclonic unit. Also, the axial distance between the paired cyclonic structures at the bottom of the column (cone 2) and cone 1 poses tough requirements because of an interaction between separation of the middlings and railings. 展开更多
关键词 Cyclonic-static micro bubble flotationcolumn CFD Flow field Vorticity magnitude Optimization design
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CFD gas–liquid simulation of oriented valve tray 被引量:2
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作者 马玉凤 纪利俊 +4 位作者 张杰旭 陈葵 武斌 吴艳阳 朱家文 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2015年第10期1603-1609,共7页
Computational fluid dynamics(CFD) has recently emerged as an effective tool for the investigation of the hydraulic parameters and efficiency of tray towers.The computation domain was established for two types of orien... Computational fluid dynamics(CFD) has recently emerged as an effective tool for the investigation of the hydraulic parameters and efficiency of tray towers.The computation domain was established for two types of oriented valves within a tray and meshed into two parts with different grid types and sizes.The volume fraction correlation concerning inter-phase momentum transfer source was fitted based on experimental data,and built in UDF for simulation.The flow pattern of oriented valve tray under different operating conditions was simulated under Eulerian-Eulerian framework with realizable k-ε model.The predicted liquid height from CFD simulation was in good agreement with the results of pressure drop and volume fraction correlations.Meanwhile,the velocity distribution and volume fraction of the two phases were demonstrated and analyzed,which are useful in design and analysis of the column trays. 展开更多
关键词 CFD simulation Oriented valve tray Gas–liquid flow Volume fraction correlation
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Motion Characteristics of Novel Floating Foundation for Offshore Wind Turbine 被引量:1
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作者 李嘉文 唐友刚 王宾 《Transactions of Tianjin University》 EI CAS 2016年第1期57-63,共7页
A novel floating foundation to support the NREL offshore 5 MW wind turbine was designed conceptually by combining the characteristics of barge and Spar. The main focus was structural design and hydrodynamic modelling.... A novel floating foundation to support the NREL offshore 5 MW wind turbine was designed conceptually by combining the characteristics of barge and Spar. The main focus was structural design and hydrodynamic modelling. Based on this novel floating foundation, the hydrodynamic performance was investigated in the frequency domain and time domain by using the wave analysis software Hydro D and Deep C from Det Norske Veritas. The frequency domain analysis was conducted to investigate the effects of the incident wave angle and water depth. The time-domain analysis was carried out to evaluate the response of the floating foundation under a selected operational condition. The hydrodynamic performances of this floating foundation with respect to time series and response spectra were also investigated in this study. 展开更多
关键词 offshore wind turbine floating foundation frequency domain analysis time domain analysis
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A Coupled Analysis of Nonlinear Sloshing and Ship Motion 被引量:4
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作者 Shuo Huang Wenyang Duan Hao Zhang 《Journal of Marine Science and Application》 2012年第4期427-436,共10页
Nonlinear interactions among incident wave, tank-sloshing and floating body coupling motion are investigated. The fully nonlinear sloshing and body-surface nonlinear free surface hydrodynamics is simulated using a Non... Nonlinear interactions among incident wave, tank-sloshing and floating body coupling motion are investigated. The fully nonlinear sloshing and body-surface nonlinear free surface hydrodynamics is simulated using a Non-Uniform Rational B-Spline (NURBS) higher-order panel method in time domain based on the potential theory. A robust and stable improved iterative procedure (Yan and Ma, 2007) for floating bodies is used for calculating the time derivative of velocity potential and floating body motion. An energy dissipation condition based on linear theory adopted by Huang (2011) is developed to consider flow viscosity effects of sloshing flow in nonlinear model. A two-dimensional tank model test was performed to identify its validity. The present nonlinear coupling sway motion results are subsequently compared with the corresponding Rognebakke and Faltinsen (2003)'s experimental results, showing fair agreement. Thus, the numerical approach presented in this paper is expected to be very efficient and realistic in evaluating the coupling effects of nonlinear sloshing and body motion. 展开更多
关键词 NONLINEAR tank-sloshing coupling motion energy dissipation
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轴向浮力驱动下的旋转圆筒热对流稳定性
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作者 陈建国 陈海昕 +1 位作者 章光华 符松 《中国科学(G辑)》 CSCD 2006年第3期263-273,共11页
研究了热对流驱动下的同轴旋转圆筒的线性稳定性问题.模拟内外圆筒温差引起的热浮力采用了Boussinesq假设,双圆筒同向旋转,其半径比为0.5, Prandtl数为0.709.通过分析发现,由于圆筒旋转离心失稳和热浮力剪切失稳两种机制的互相竞争... 研究了热对流驱动下的同轴旋转圆筒的线性稳定性问题.模拟内外圆筒温差引起的热浮力采用了Boussinesq假设,双圆筒同向旋转,其半径比为0.5, Prandtl数为0.709.通过分析发现,由于圆筒旋转离心失稳和热浮力剪切失稳两种机制的互相竞争,临界失稳中性曲线发现间断现象,失稳模态产生跳跃,形成“孤岛”效应.在研究稳定性问题的同时还对求解圆筒稳定性问题的数值方法进行了研究和探讨. 展开更多
关键词 失稳孤岛 旋转圆筒 浮力流动
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丹真贡布诗歌写作的流动美
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作者 黄波 《民族文学研究》 CSSCI 北大核心 1998年第2期32-33,共2页
当代著名藏族诗人丹真贡布,系甘肃省夏河县拉卜楞人,生于1934年12月,1955年因叙事长诗《拉伊勒与隆木措》而一举成名。著有诗集《羚之街》和《溪流集》。1996年8月22日病逝于兰州。
关键词 诗歌写作 流动 动态描写 流动浮力 流动的美感 拉卜楞 布达拉宫 动态美 《拉奥孔》 甘肃省
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Design of Ocean Floating Structures:Prediction of Hydrodynamic Coefficients
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作者 LI Wei FAN Shaotao +1 位作者 WANG Jinxi LIU Tianhui 《南方能源建设》 2024年第6期18-32,共15页
[Introduction] Accurate calculation of the hydrodynamic coefficients for floating structures and the investigation of the flow field distribution around floating bodies on the marine free surface are essential for imp... [Introduction] Accurate calculation of the hydrodynamic coefficients for floating structures and the investigation of the flow field distribution around floating bodies on the marine free surface are essential for improving the engineering design and application of marine structures.[Method] This study utilized the computational fluid dynamics(CFD) approach and the Reynolds Averaged NavierStokes(RANS) method and considered the effects of viscosity and free surface interactions on the hydrodynamic behavior of floating structures.By employing the dynamic mesh technique,this study simulated the periodic movements of simplified three-dimensional(3D)shapes:spheres,cylinders,and cubes,which were representative of complex marine structures.The volume of fluid(VOF) method was leveraged to accurately track the nonlinear behavior of the free surface.In this analysis,the added mass and damping coefficients for the fundamental modes of motion(surge,heave,and roll) were calculated across a spectrum of frequencies,facilitating the fast determination of hydrodynamic forces and moments exerted on floating structures.[Result] The results of this study are not only consistent with the results of the 3D potential flow theory but also further reflect the role of viscosity.This method can be used for precise calculation of the hydrodynamic coefficients of floating structures and for describing the flow field of such structures in motion on a free surface.[Conclusion] The methodology presented goes beyond the traditional potential flow approach. 展开更多
关键词 Computational fluid dynamics ocean floating structures hydrodynamic coefficients fluid-structure interaction
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