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超声速钝锥湍流边界层DNS入口边界条件的研究 被引量:6
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作者 董明 周恒 《应用数学和力学》 CSCD 北大核心 2008年第8期893-904,共12页
如何选取恰当的入口条件,是进行湍流边界层直接数值模拟时必须考虑的一个问题.为此建议了一种方法,只需要有平板湍流边界层时间模式直接数值模拟(DNS)所得的一个瞬时的流场,而且其Mach数、Reynolds数及壁面温度条件无需和实际问题中的... 如何选取恰当的入口条件,是进行湍流边界层直接数值模拟时必须考虑的一个问题.为此建议了一种方法,只需要有平板湍流边界层时间模式直接数值模拟(DNS)所得的一个瞬时的流场,而且其Mach数、Reynolds数及壁面温度条件无需和实际问题中的完全相同,就可导出超声速钝锥湍流边界层空间模式直接数值模拟所需的入口条件.通过3个典型算例,将结果与用其它方法所得结果相比,证实了该方法的可行性. 展开更多
关键词 湍流边界层 直接数值模拟(dns) 超声速 钝锥 入口条件
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Re-understanding the law-of-the-wall for wall-bounded turbulence based on in-depth investigation of DNS data 被引量:4
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作者 Bochao Cao Hongyi Xu 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2018年第5期793-811,共19页
Based on direct numerical simulation (DNS) data of the straight ducts,namely square and rectangular annular ducts,detailed analyses were conducted for the mean streamwise velocity,relevant velocity scales,and turbulen... Based on direct numerical simulation (DNS) data of the straight ducts,namely square and rectangular annular ducts,detailed analyses were conducted for the mean streamwise velocity,relevant velocity scales,and turbulence statistics.It is concluded that turbulent boundary layers (TBL) should be broadly classified into three types (Type-A,-B,and-C) in terms of their distribution patterns of the time-averaged local wall-shear stress (τw) or the mean local frictional velocity (uτ).With reference to the Type-A TBL analysis by von Karman in developing the law-of-the-wall using the time-averaged local frictional velocity (uτ) as scale,the current study extended the approach to the Type-B TBL and obtained the analytical expressions for streamwise velocity in the inner-layer using ensemble-averaged frictional velocity (ūτ) as scale.These analytical formulae were formed by introducing the general damping and enhancing functions.Further,the research applied a near-wall DNS-guided integration to the governing equations of Type-B TBL and quantitatively proved the correctness and accuracy of the inner-layer analytical expressions for this type. 展开更多
关键词 direct numerical simulation (dns) Wall-bounded TURBULENCE TURBULENT boundary layer
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Boundary-layer disturbances subjected to free-stream turbulence and simulation on bypass transition 被引量:3
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作者 Hong QIN Ming DONG 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2016年第8期967-986,共20页
The phenomena associated with the entrainment of free-stream turbulence (FST) into boundary-layer flows are relevant for a number of subjects. It has been be- lieved that the continuous spectra of the Orr-Sommerfeld... The phenomena associated with the entrainment of free-stream turbulence (FST) into boundary-layer flows are relevant for a number of subjects. It has been be- lieved that the continuous spectra of the Orr-Sommerfeld (O-S)/Squire equations describe the entrainment process, and thus they are used to specify the inlet condition in simulation of bypass transition. However, Dong and Wu (Dong, M. and Wu, X. On continuous spectra of the Orr-Sommerfeld/Squire equations and entrainment of free-stream vortical disturbances. Journal of Fluid Mechanics, 732, 616-659 (2013)) pointed out that continuous spectra exhibit several non-physical features due to neglecting the non-parallelism. They further proposed a large-Reynolds-number asymptotic approach, and showed that the non-parallelism is a leading-order effect even for the short-wavelength disturbance, for which the response concentrates in the edge layer. In this paper, the asymptotic solution is verified numerically by studying its evolution in incompressible boundary layers. It is found that the numerical results can be accurately predicted by the asymptotic solution, implying that the latter is adequate for moderate Reynolds numbers. By introducing a series of such solutions as the inflow perturbations, the bypass transition is investigated via the direct numerical simulation (DNS). The transition processes, including the evolution of streaks, the amplification of secondary-instability modes, and the emergence of turbulent spots, agree with the experimental observations. 展开更多
关键词 free-stream turbulence (FST) bypass transition boundary layer ASYMPTOTIC direct numerical simulation (dns
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DIRECT NUMERICAL SIMULATION OF TURBULENT HEAT TRANSFER IN A WALL-NORMAL ROTATING CHANNEL FLOW 被引量:4
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作者 LI Bu-yang LIU Nan-sheng LU Xi-yun 《Journal of Hydrodynamics》 SCIE EI CSCD 2006年第1期26-31,共6页
Direct Nmerical Simulation (DNS) of turbulent heat transfer in a wall-normal rotating channel flow has been carried out for the rotation number Nr from 0 to 0.1, the Reynolds number 194 based on the friction velocit... Direct Nmerical Simulation (DNS) of turbulent heat transfer in a wall-normal rotating channel flow has been carried out for the rotation number Nr from 0 to 0.1, the Reynolds number 194 based on the friction velocity of non ro taring case and the half-height of the channel, and the Prandtl number 1. The objective of this study is to reveal the effects of rotation on the characteristics of turbulent flow and heat transfer. Based on the present calculated results, two typical rotation regimes are identified. When 0 〈 Nr 〈 0.06, turbu lence and thermal statistics correlated with the spanwise veloc ity fluctuation are enhanced since the shear rate of spanwise mean flow induced by Coriolis force increases; however, the other statistics are suppressed. When Nr 〉 0.06, turbulence and thermal statistics are suppressed significantly because the Coriolis force effect plays as a dominated role in the rotating flow. Remarkable change of the direction of near wall streak structures based on the velocity and temperature fluctuations is identified. 展开更多
关键词 direct numerical simulation (dns wallnormal rotating channel flow turbulent heat transfer thermal statistics
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The direct numerical simulation of pipe flow 被引量:1
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作者 LIU Zheng-gang DU Guang-sheng SHAO Zhu-feng 《Journal of Hydrodynamics》 SCIE EI CSCD 2013年第1期125-130,共6页
The conservative difference scheme and the third-order Runge-Kutta scheme in combination with the the Crank-Nicholson scheme are used to directly simulate the flow field in a pipe with the Reynolds number of 2 600. Th... The conservative difference scheme and the third-order Runge-Kutta scheme in combination with the the Crank-Nicholson scheme are used to directly simulate the flow field in a pipe with the Reynolds number of 2 600. The flow field, including the velocity distribution and the turbulence intensity, is obtained by the direct numerical simulation. From the calculated results, the ratio of the linear average velocity along the ultrasonic propagation path to the profile average velocity on the pipe cross-section is also obtained in an ultrasonic flow meter. It is concluded that the direct numerical simulation method can be used to study the ratio of the profile-linear average velocity at low Reynolds number conditions in the transition region and to improve the measurement accuracy of the ultrasonic flow meter. 展开更多
关键词 direct numerical simulation (dns PIPE turbulence intensity Reynolds stress
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Experimental and numerical study of ?ow structures of the second-mode instability
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作者 Yiding ZHU 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2019年第2期273-282,共10页
Flow structures of a Mach 6 transitional boundary layer over a 260 mm long flared cone are investigated by the particle image velocimetry(PIV). Particle images near the curved wall are initially transformed into surfa... Flow structures of a Mach 6 transitional boundary layer over a 260 mm long flared cone are investigated by the particle image velocimetry(PIV). Particle images near the curved wall are initially transformed into surface-fitted orthogonal coordinates and spliced with their 180?-symmetric images to satisfy a no-slip condition at the wall.The results are then reversely transformed to the physical domain. Direct numerical simulation(DNS) is also performed to validate the experimental results. The experimental and numerical results are in agreement, indicating a strong dilatation process within the second-mode instability. 展开更多
关键词 HYPERSONIC transition particle image velocimetry(PIV) direct numerical simulation(dns)
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DIRECT NUMERICAL SIMULATIONS OF TURBULENT CHANNEL FLOWS WITH CONSIDERATION OF THE BUOYANCY EFFECT OF THE BUBBLE PHASE
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作者 LIU Nan-sheng CHENG Bao-guo +1 位作者 QUE Xia LU Xi-yun 《Journal of Hydrodynamics》 SCIE EI CSCD 2011年第3期282-288,共7页
Turbulent channel flows with consideration of the buoyancy effect of the bubble phase is investigated by means of the Direct Numerical Simulation (DNS). This two-phase system is solved by a two-way coupling Lagrangi... Turbulent channel flows with consideration of the buoyancy effect of the bubble phase is investigated by means of the Direct Numerical Simulation (DNS). This two-phase system is solved by a two-way coupling Lagrangian-Eulerian approach. The Reynolds number based on the friction velocity and the half-width of the channel is 194, and the gravitational acceleration varies from -0.5 to 0.5, ranging from the upflow to the downflow cases. This study aims to reveal the influence of buoyancy on the turbulence behavior and the bubble motion. Some typical statistical quantities, including the averaged velocities and velocity fluctuations for the fluid and bubble phases, as well as the flow structures of the turbulence fluctuations, are analyzed. 展开更多
关键词 direct numerical simulations (dns turbulent bubbly flow upflow/downflow turbulence fluctuations bubble statistics turbulence structures
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Numerical investigation of turbulent channel flow controlled by spatially oscillating spanwise Lorentz force
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作者 Wentang WU Yanji HONG Baochun FAN 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2015年第9期1113-1120,共8页
A formulation of the skin-friction drag related to the Reynolds shear stress in a turbulent channel flow is derived. A direct numerical simulation (DNS) of the turbulent control is performed by imposing the spatiall... A formulation of the skin-friction drag related to the Reynolds shear stress in a turbulent channel flow is derived. A direct numerical simulation (DNS) of the turbulent control is performed by imposing the spatially oscillating spanwise Lorentz force. Under the action of the Lorentz force with several proper control parameters, only the periodi- cally well-organized streamwise vortices are finally observed in the near-wall region. The Reynolds shear stress decreases dramatically, especially in the near-wall area, resulting in a drag reduction. 展开更多
关键词 turbulent channel flow direct numerical simulation (dns drag reduction Lorentz force
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Direct numerical simulation of the viscoelastic channel flow using Giesekus model with variable parameters
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作者 Wei-guo Gu Yu Li De-zhong Wang 《Journal of Hydrodynamics》 SCIE EI CSCD 2019年第2期326-332,共7页
The paper presents a direct numerical simulation(DNS)for the drag-reducing channel flow using the Giesekus model with variable parameters.It is assumed that the relaxation time in the constitutive equation is varied d... The paper presents a direct numerical simulation(DNS)for the drag-reducing channel flow using the Giesekus model with variable parameters.It is assumed that the relaxation time in the constitutive equation is varied depending on the local shear rate.The maximal drag reduction rate is obtained when variable parameters are applied in the Giesekus model at a high Weissenberg number.The Reynolds shear stress is reduced when the Weissenberg number increases.In this case,the turbulence generation and transportation are further weakened and increasingly approach to the values in the experiments. 展开更多
关键词 VISCOELASTIC FLUID Giesekus model direct numeriCAL simulation(dns) VARIABLE parameters
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Direct Numerical Simulation of Vertical Rotating Turbulent Open-Channel Flow with Heat Transfer
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作者 Bu-Yang Li Nan-Sheng Liu Xi-Yun Lu 《Communications in Computational Physics》 SCIE 2006年第2期336-361,共26页
Direct numerical simulation of vertical rotating open-channel flow with heat transfer has been carried out for the rotation number Nτfrom 0 to 0.1,the Prandtl number 1,and the Reynolds number 180 based on the frictio... Direct numerical simulation of vertical rotating open-channel flow with heat transfer has been carried out for the rotation number Nτfrom 0 to 0.1,the Prandtl number 1,and the Reynolds number 180 based on the friction velocity of non-rotating flow and the height of the channel.The ob jective of this study is to reveal the effect of rotation on the characteristics of turbulent flow and heat transfer,in particular near the free surface and the wall of the open-channel.Statistical quantities,e.g.,the mean velocity,temperature and their fluctuations,turbulent heat fluxes,and turbulence structures,are analyzed.The depth of surface-influenced layer decreases with the increase of the rotation rate.In the free surface-influenced layer,the turbulence and thermal statistics are suppressed due to the effect of rotation.In the wall-influenced region,two typical rotation regimes are identified.In the weak rotation regime with 0<Nτ<0.06 approximately,the turbulence and thermal statistics correlated with the spanwise velocity fluctuation are enhanced since the shear rate of spanwise mean flow induced by Coriolis force increases;however,the other statistics are suppressed.In the strong rotation regime with Nτ>0.06,the turbulence and thermal statistics are suppressed significantly because the Coriolis force effect plays a dominant role in the rotating flow.To elucidate the effect of rotation on turbulent flow and heat transfer,the budget terms in the transport equations of Reynolds stresses and turbulent heat fluxes are investigated.Remarkable change of the direction of streak structures based on the velocity and temperature fluctuations is discussed. 展开更多
关键词 direct numerical simulation(dns) rotating turbulent flow turbulent heat transfer thermal statistics coherent structure
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A rescaling algorithm for multi-relaxation-time lattice Boltzmann method towards turbulent flows with complex configurations
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作者 Haoyang LI Weijian LIU Yuhong DONG 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2023年第9期1597-1612,共16页
Understanding and modeling flows over porous layers are of great industrial significance.To accurately solve the turbulent multi-scale flows on complex configurations,a rescaling algorithm designed for turbulent flows... Understanding and modeling flows over porous layers are of great industrial significance.To accurately solve the turbulent multi-scale flows on complex configurations,a rescaling algorithm designed for turbulent flows with the Chapman-Enskog analysis is proposed.The mesh layout and the detailed rescaling procedure are also introduced.Direct numerical simulations(DNSs)for a turbulent channel flow and a porous walled turbulent channel flow are performed with the three-dimensional nineteen-velocity(D3Q19)multiple-relaxation-time(MRT)lattice Boltzmann method(LBM)to validate the accuracy,adaptability,and computational performance of the present rescaling algorithm.The results,which are consistent with the previous DNS studies based on the finite difference method and the LBM,demonstrate that the present method can maintain the continuity of the macro values across the grid interface and is able to adapt to complex geometries.The reasonable time consumption of the rescaling procedure shows that the present method can accurately calculate various turbulent flows with multi-scale and complex configurations while maintaining high computational efficiency. 展开更多
关键词 slattice Boltzmann method(LBM) direct numerical simulation(dns) rescaling algorithm complex configuration
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不同桥墩概化方法在防洪评价中的应用研究 被引量:1
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作者 张铄涵 陈晖 张安琪 《广东水利水电》 2023年第7期34-39,44,共7页
基于非结构网格和二维水流数学模型,采用4种常用的桥墩概化方法,模拟计算了桥梁建设前后的壅水和流速、流向变化,得出不同概化方法在防洪评价中的适用性,为桥梁工程的建设以及防洪评价报告的审批提供一定的技术参考。计算结果表明,将桥... 基于非结构网格和二维水流数学模型,采用4种常用的桥墩概化方法,模拟计算了桥梁建设前后的壅水和流速、流向变化,得出不同概化方法在防洪评价中的适用性,为桥梁工程的建设以及防洪评价报告的审批提供一定的技术参考。计算结果表明,将桥墩作为陆地边界概化的直接模拟法(1)能最好地反映实际水工结构和地形的变化,计算结果可作为防洪评价的重要依据。 展开更多
关键词 桥墩 直接模拟法 局部阻力修正法 壅水 流速流向 防洪评价
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Numerical study of the near-wall vortical structures in particle-laden turbulent flow by a new vortex identification method-Liutex
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作者 Farid Rousta Goodarz Ahmadi +1 位作者 Bamdad Lessani Chaoqun Liu 《Journal of Hydrodynamics》 SCIE EI CSCD 2024年第1期53-60,共8页
This study investigates turbulent particle-laden channel flows using direct numerical simulations employing the Eulerian-Lagrangian method.A two-way coupling approach is adopted to explore the mutual interaction betwe... This study investigates turbulent particle-laden channel flows using direct numerical simulations employing the Eulerian-Lagrangian method.A two-way coupling approach is adopted to explore the mutual interaction between particles and fluid flow.The considered cases include flow with particle Stokes number varying from St=2 up to St=100 while maintaining a constant Reynolds number of Reτ=180 across all cases.A novel vortex identification method,Liutex(Rortex),is employed to assess its efficacy in capturing near-wall turbulent coherent structures and their interactions with particles.The Liutex method provides valuable information on vortex strength and vectors at each location,enabling a detailed examination of the complex interaction between fluid and particulate phases.As widely acknowledged,the interplay between clockwise and counterclockwise vortices in the near-wall region gives rise to low-speed streaks along the wall.These low-speed streaks serve as preferential zones for particle concentration,depending upon the particle Stokes number.It is shown that the Liutex method can capture these vortices and identify the location of low-speed streaks.Additionally,it is observed that the particle Stokes number(size)significantly affects both the strength of these vortices and the streaky structure exhibited by particles.Furthermore,a quantitative analysis of particle behavior in the near-wall region and the formation of elongated particle lines was carried out.This involved examining the average fluid streamwise velocity fluctuations at particle locations,average particle concentration,and the normal velocity of particles for each set of particle Stokes numbers.The investigation reveals the intricate interplay between particles and near-wall structures and the significant influence of particles Stokes number.This study contributes to a deeper understanding of turbulent particle-laden channel flow dynamics. 展开更多
关键词 Turbulent channel flow particle-laden flow direct numerical simulation(dns) Eulerian-Lagrangian vortex identification turbulence coherent structures Liutex
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多孔介质流动的直接数值模拟 被引量:23
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作者 邓彩华 童亮 +2 位作者 陈壁峰 肖金生 皮埃尔.贝纳德 《武汉理工大学学报(交通科学与工程版)》 2011年第6期1257-1260,共4页
基于计算流体动力学软件Fluent建立了一个二维DNS模型,研究了多孔介质中的流动阻力和压降.模拟时对填充的圆柱粒子采用了2种几何排列方式,即直排和叉排.DNS直排模型的压差为53.5Pa,接近于采用原始系数A=150,B=1.75的尔格方程计算结果55.... 基于计算流体动力学软件Fluent建立了一个二维DNS模型,研究了多孔介质中的流动阻力和压降.模拟时对填充的圆柱粒子采用了2种几何排列方式,即直排和叉排.DNS直排模型的压差为53.5Pa,接近于采用原始系数A=150,B=1.75的尔格方程计算结果55.6Pa.叉排模型的压差为65.1Pa,接近于采用修正系数A=180,B=1.80的尔格方程计算结果62.1Pa.对于真实多孔介质材料的模拟来说,圆柱形粒子叉排比直排更为准确.因此DNS结果确认了修正系数组(A=180,B=1.80)比原始系数组(A=150,B=1.75)更适合尔格方程模型.应用文中推荐的DNS方法,通过采用不同的粒子几何排列方式、填充不同形状的粒子可以进一步地预测尔格方程系数或改善其他的多孔介质模型. 展开更多
关键词 多孔介质 流体流动 阻力系数 直接数值模拟 dns
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超声速空间发展燃烧反应剪切层放热效应分析 被引量:5
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作者 苗文博 程晓丽 王强 《空气动力学学报》 EI CSCD 北大核心 2008年第3期339-343,共5页
为探索化学反应对混合燃烧的影响机理,本文从流体力学基本方程出发,采用直接数值模拟方法研究了二维7组元/8反应化学非平衡剪切层的流动,讨论了数值上考虑化学反应放热对流动混合的影响,并分析其机理。研究发现:在相同的基频扰动促发下... 为探索化学反应对混合燃烧的影响机理,本文从流体力学基本方程出发,采用直接数值模拟方法研究了二维7组元/8反应化学非平衡剪切层的流动,讨论了数值上考虑化学反应放热对流动混合的影响,并分析其机理。研究发现:在相同的基频扰动促发下,考虑化学反应时混合层厚度变薄,且混合层的厚度会随着燃料组分的增大先变小后增大,涡量厚度发展至饱和的位置逐渐靠后;反应放热和组分含量影响湍流切应力和湍动能的变化,涡量厚度随着湍动能以及湍流切应力规律性变化,随着燃料组分的增加,湍动能、湍流切应力及混合层厚度非单调变化,存在极值点。 展开更多
关键词 化学非平衡流 混合层 涡量厚度 直接数值模拟
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室内空气流动的直接数值模拟 被引量:3
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作者 孙在 黄震 王嘉松 《上海交通大学学报》 EI CAS CSCD 北大核心 2007年第5期677-680,共4页
应用直接数值模拟(DNS)技术,采用高分辨率的网格,计算了一个三维非定常的室内通风流场.对比激光多普勒仪器的测量数据,DNS显示了优异的预测能力,特别是准确地捕捉速度峰值的能力.其计算结果能够详细地描述出室内空气湍流流动的演变和细... 应用直接数值模拟(DNS)技术,采用高分辨率的网格,计算了一个三维非定常的室内通风流场.对比激光多普勒仪器的测量数据,DNS显示了优异的预测能力,特别是准确地捕捉速度峰值的能力.其计算结果能够详细地描述出室内空气湍流流动的演变和细微的漩涡结构,为设计室内通风环境和研究室内污染物扩散传输提供了强有力的工具. 展开更多
关键词 直接数值模拟 室内 空气流动 预测
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中等雷诺数方柱绕流的直接数值模拟及涡系分析 被引量:6
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作者 王建春 吴乘胜 +1 位作者 王星 徐金秀 《船舶力学》 EI CSCD 北大核心 2019年第8期893-905,共13页
作为一种典型的钝体绕流,方柱绕流具有物体几何外形简单而流场结构非常复杂的特性,常规的基于RANS的数值计算方法难以准确模拟。DNS不使用任何湍流模型,直接求解完整的非定常流动控制方程组,模拟包括脉动在内的湍流所有非定常流动量的... 作为一种典型的钝体绕流,方柱绕流具有物体几何外形简单而流场结构非常复杂的特性,常规的基于RANS的数值计算方法难以准确模拟。DNS不使用任何湍流模型,直接求解完整的非定常流动控制方程组,模拟包括脉动在内的湍流所有非定常流动量的时空演变过程,是湍流数值模拟中最精确的方法,在复杂流动数值模拟方面的应用潜力巨大。本文自主设计和编制并行数值模拟程序,使用基于"神威·太湖之光"国产CPU架构的大规模并行计算,开展了中等雷诺数(Re=10 000)方柱绕流的直接数值模拟。其中:不可压N-S方程组采用基于交错网格的有限体积法离散;压力-速度耦合采用SIMPLE算法处理;离散得到的代数方程组采用Gauss-Seidel迭代求解;时间步进采用Euler隐式格式,对流项采用QUICK格式,耗散项采用中心差分格式;数值模拟程序的并行化使用MPI方法处理。文中重点分析了方柱绕流的复杂涡系结构,同时给出了部分湍流统计结果,并通过与RANS和LES模拟结果的对比分析,展现了DNS在复杂精细流场模拟方面的优势。 展开更多
关键词 直接数值模拟 方柱绕流 涡系结构 MPI并行 国产CPU架构
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微重力量值对气液两相流相分布及液相湍流统计量影响的数值研究 被引量:3
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作者 庞明军 魏进家 宇波 《空间科学学报》 CAS CSCD 北大核心 2012年第3期368-375,共8页
气液两相流在空间领域具有广阔的应用前景,深入理解微重力量值(微重力大小)对相分布和液相湍流的影响十分必要.采用欧拉-拉格朗日双向耦合模型深入研究了不同微重力量值对相分布和液相湍流的影响.液相速度场通过直接数值模拟求解,气泡... 气液两相流在空间领域具有广阔的应用前景,深入理解微重力量值(微重力大小)对相分布和液相湍流的影响十分必要.采用欧拉-拉格朗日双向耦合模型深入研究了不同微重力量值对相分布和液相湍流的影响.液相速度场通过直接数值模拟求解,气泡的运动轨迹由牛顿运动方程跟踪.研究表明,气泡分布和液相湍流与微重力量值均具有直接联系.在低微重力量值下,气泡近似均匀分布在槽道内,且对液相湍流统计量几乎没有影响;然而当微重力量值较高时,大量气泡聚集在壁面附近,液相湍流由于气泡的注入受到极大调制. 展开更多
关键词 泡状流 微重力量值 相分布 液相湍流 直接数值模拟
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压力梯度作用下相干结构的演化 被引量:6
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作者 陆利蓬 李兆瑞 《中国工程科学》 2002年第11期50-56,共7页
采用共振三波的一个周期作为湍流边界层近壁区相干结构的初值 ,用直接数值模拟方法对有压力梯度 ,包括定常压力梯度和变压力梯度作用下相干结构的演化进行了研究 ,得出其各种特性的变化与实验观测到的结果一致。压力梯度对相干结构初始... 采用共振三波的一个周期作为湍流边界层近壁区相干结构的初值 ,用直接数值模拟方法对有压力梯度 ,包括定常压力梯度和变压力梯度作用下相干结构的演化进行了研究 ,得出其各种特性的变化与实验观测到的结果一致。压力梯度对相干结构初始扰动波的选择以及演化过程都起作用 ,相比之下对前者的作用更大。条纹结构和流向涡之间有某种内在的紧密的联系 ,可能是产生流向涡的起因。 展开更多
关键词 演化 相干结构 湍流边界层 压力梯度 数值模拟 流体力学
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特隆勃墙通道内自然对流边界层流动 被引量:1
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作者 何云 刘滔 +4 位作者 罗川旭 高文峰 林文贤 李明 郑勤红 《太阳能学报》 EI CAS CSCD 北大核心 2009年第1期69-74,共6页
利用标度分析得到表征特隆勃墙通道内空气自然对流的宏观特征参数与系统的运行控制参数和结构参数之间的内在相关关系式,并利用直接数值模拟计算结果对其进行验证和定量化。
关键词 特隆勃墙通道 自然对流 标度分析 直接数值模拟
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