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Enabling Technologies in the Problem Solving Environment HEDP

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Communications in Computational Physics 2008年第10期4卷 1170-1193页

作者： Lijun Xie Yao Zheng Jianjun Chen jianfeng zou Center for Engineering and Scientific Computation and School of Aeronautics and Astronautics Zhejiang UniversityZhejiang 310027China

Enabling technologies are those technologies preparing input data,analyzing output data and facilitating the whole processes for numerical *** paper outlines current enabling technologies for large-scale multidisciplinary simulations used in the High End Digital Prototyping(HEDP)system,a problem solving environment equipped with capability of mesh generation and large-scale visualization.A problem solving environment is a computer system that provides all the computational facilities necessary to solve a target class of *** generation continues to be the pacing technology for a practical numerical analysis,which is essential to yielding an accurate and efficient ***-scale visualization maps the massive data to some kinds of scenes interactively,which can be realized through a tiled display wall system with distributed visualization *** is designed for large-scale andmultidisciplinary simulations,and there are four categories of modules involved,namely pre-processing module,computing module,post-processing module,and platform control *** these modules are coupled through a software bus,which makes the modules integrated *** design principles and applications of the HEDP environment are addressed in this paper.

关键词： Enabling technology large-scale simulation mesh generation problem solving environment distributed visualization

Numerical analysis of turbulence characteristics in a flat-plate flow with riblets control

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Advances in Aerodynamics 2022年第1期4卷 614-641页

作者： Yang Zhang Zhixian Ye Binghua Li Lan Xie jianfeng zou Yao Zheng Center for Engineering and Scientific Computation School of Aeronautics and AstronauticsZhejiang UniversityHangzhou310027China

A comparative study about riblets-controlled turbulent boundary layers has been performed to investigate the turbulence characteristics associated with drag reduction in a compressive flat-plate flow(where the free-stream Mach number is 0.7)by means of direct numerical simulations(DNSs).With a setting of the triangular riblets(s+≈30.82,h+≈15.41)settled on the Reτ≈500 turbulent boundary layer,an effective global drag reduction was *** comparing velocity and its fluctuation distribution,vorticity fluctuation and streaks structures between the smooth and riblets flat-plate cases,two roles of lifting and rectification in terms of riblets drag control are revealed that the micro-scale riblets can lift up logarithmic-law region of the boundary layer,which leads to a smaller wall friction velocity and thus a drag *** streamwise vortices and its fluctuation structures are shifted upward,thus the interactions between them and the wall surface are weakened,which causes the suppressed intensity of Reynolds normal stresses,streamwise vorticity and turbulent kinetic energy production inside the ***,the streaks associated with streamwise velocity or 3D vortices are ruled from the distorted to long and straight structures as they pass through the riblets,indicating an ability of riblets to turn turbulence into a more ordered state.

关键词： Riblets control Drag reduction Turbulent boundary layer Large-scale simulation

Mesh Adaptation for Curing the Pathological Behaviors of an Upwind Scheme

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Communications in Computational Physics 2022年第2期31卷 626-644页

作者： Yifan Xia Jianjing Zheng jianfeng zou Jifa Zhang Gaofeng Wang Yao Zheng School of Aeronautics and Astronautics Zhejiang UniversityHangzhou 310027P.R.China Center for Hypergravity Experimental and Interdisciplinary Research Zhejiang UniversityHangzhou 310027P.R.China

In present paper,mesh adaptation is applied for curing the pathological behaviors of the enhanced time-accurate upwind scheme(Loh&Jorgenson,AIAAJ 2016).In the original ETAU(enhanced time-accurate upwind)scheme,a multidimensional dissipation model is required to cure the pathological *** multi-dimensional dissipation model will increase the global dissipation level reducing numerical *** present work,the metric-based mesh adaptation strategy provides an alternative way to cure the pathological behaviors of the shock *** Hessian matrix of flow variables is applied to construct the metric,which represents the curvature of the physical *** adapting operation can well refine the anisotropic meshes at the location with large *** numerical results show that the adaptation of mesh provides a possible way to cure the pathological behaviors of upwind schemes.

关键词： Metric tensor mesh adaptation finite volume scheme unstructured grid

Wake structures of two spheres in tandem arrangement at various gaps for Re=300

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Progress in Natural Science:Materials International 2005年第2期15卷 37-41页

作者： zou jianfeng*, REN Anlu, DENG Jian and CHEN Wenqu(Department of Mechanics, Zhejiang University, Hangzhou 310027, China) Dept. of Mechanics Zhejiang Univ. Hangzhou 310027 China

The virtual boundary method is extended to a 3D application and used to simulate the flow field of two spheres in tandem arrangement for a Reynolds number of 300. The wake structures and flow spectra at various gaps are investigated. The numerical results show that for small gaps (≈1.5), due to the mutual suppress between the wakes of the two spheres, the full flow field is stable and axisymmetric. As the gap is increased to 2.0, an asymmetric but stable flow is constructed through a certain bifurcation. The downstream wake structure is characterized by a double-thread vortex structure that comprises two slender parallel vortex tubes. The double-thread structure has a planar symmetry at gap 2.0. The hairpin-shape vortices are periodically shed from the downstream sphere at gap 2.5, but the planar symmetry persists. The vortex structures at gaps ranging from 3.0 to 4.0 are irregular and the flow field is undergoing a kind of 3D transition. It is up to the large gap 5.0 that the hairpin-shape structures are reconstructed behind the upstream and the downstream sphere, and the planar symmetry is resumed. All these numerical computations were performed on an SGI Origin3900 machine at the Center for Engineering and Scientific Computation of Zhejiang University.

关键词： virtual boundary method flow past two spheres wake structure flow spectra

The Growth Rate of China's Foreign Trade May Fall down in 2004

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China's Foreign Trade 2003年第12期 12-13页

作者： zou jianfeng

Market opens up: facts speak louder than wordsThe 'Tenth five-year plan' being completed ahead of timeThe growth rate of China's foreign trade may obviously fall down next

关键词：中国对外贸易 2004年增长速度发展趋势

Frequency response of liquid jet under nozzle velocity disturbance

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Hangkong Dongli Xuebao/Journal of Aerospace Power 2022年第4期37卷 743-754页

作者： Zhou, Chenglin zou, jianfeng Zhang, Yang Ye, Lin School of Aeronautics and Astronautics Zhejiang University Hangzhou 310027 China Digital Technology Research Institute CHINT Group Corporation Hangzhou 310052 China

Based on the VOF (volume of fluid) interface capture method and the dynamic adaptive grid technique, a direct numerical simulation of the breakup process of a circular jet was carried *** surface morphology of the circular jet and the response characteristics of liquid ligaments and droplets under different disturbance frequencies were *** results showed that Rayleigh linearized dispersion theory can well explain the instability process of jet surface *** the nozzle disturbance frequency (66.6 kHz) was less than the theoretical critical value of 95.5 kHz, the jet gradually lost stability with the evolution of time and *** it was greater than the critical value, the amplitude of surface wave gradually weakened and the liquid core became *** the surface wave was unstable, the falling droplets impacted the nodal structure and impact dents left on its surface;with the increase of nodal amplitude, the liquid film broke through, and then a large number of detached liquid ligaments and droplets were *** frequency disturbance can reduce the velocity fluctuation of the jet head and slow down the atomization process of the *** breakup of the jet surface wave and the breakup process of the liquid core head determined the size of the SMD (Sauter mean diameter) of spray field, and there existed mutual coupling between them. © 2022, Editorial Department of Journal of Aerospace Power. All right reserved.

关键词： Surface morphology

Foreign trade:seeking high growthrate by surmounting difficulties

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China's Foreign Trade 2003年第6期 15-16页

作者： zou jianfeng

In 2003 the internal and external environments of China′s foreign trade are better than thosc last ycar,but some restrictions still *** is rather diffieult for export growth rate to keep as high as last year,but ther... 详细信息

关键词：中国进出口贸易发展现状国内形势国际贸易形势发展趋势

Export Prosp ects 2003

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China's Foreign Trade 2003年第2期 16-17页

作者： zou jianfeng

China achieved unprecedented breakthroughs in export growth in 2002. Will China be able to maintain a high growth rate in exports this year? Will there be any changes in the model export growth? And will the country's economic growth continue to depend on the growth of exports? To answer these questions, reporter zou jianfeng talked with a number of

关键词：中国出口贸易经济增长 2003年贸易政策

Network Virtualization Based Seamless Networking Scheme for Fiber-Wireless （FiWi） Networks

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China Communications 2014年第5期11卷 1-16页

作者： DAI Qinglong zou jianfeng SHOU Guochu HU Yihong GUO Zhigang Beijing Laboratory of Network System Architecture and Convergence School of Information and Communication EngineeringBeij ing University of Posts and Telecommunications Beijing 100876 China

In order to reduce cost and complexity,fiber-wireless(FiWi) networks emerge,combining the huge amount of available bandwidth of fiber networks and the flexibility,mobility of wireless ***,there is still a long way to go before taking fiber and wireless systems as fully integrated *** this paper,we propose a network visualization based seamless networking scheme for FiWi networks,including hierarchical model,service model,service implementation and dynamic bandwidth assignment(DBA).Then,we evaluate the performance changes after network virtualization is *** for nodes,bandwidth for links and overheads leaded by network virtualization are *** performance of our proposed networking scheme is evaluated by simulation and real implementations,*** results show that,compared to traditional networking scheme,our scheme has a better performance.

关键词： fiber-wireless networks network virtualization service future network