检索结果-南通市图书馆

A Two-Dimensional Third-Order CESE Scheme for Ideal MHD Equations

在线全文

学校读者我要写书评

暂无评论

Communications in Computational Physics 2023年第6期33卷 94-115页

作者： Yufen Zhou xueshang feng SIGMA Weather Group State Key Laboratory for Space WeatherNational Space Science CenterChinese Academy of ScienceBeijing 100190China Shenzhen Key Laboratory of Numerical Prediction for Space Storm Institute of Space Science and Applied TechnologyHarbin Institute of TechnologyShenzhen 518055China

In this paper,we construct a two-dimensional third-order space-time conservation element and solution element(CESE)method and apply it to the magnetohydrodynamics(MHD)*** third-order CESE method preserves all the favorable attributes of the original second-order CESEmethod,such as:(i)flux conservation in space and time without using an approximated Riemann solver,(ii)genuine multi-dimensional algorithm without dimensional splitting,(iii)the use of the most compact mesh stencil,involving only the immediate neighboring cells surrounding the cell where the solution at a new time step is sought,and(iv)an explicit,unified space-time integration procedure without using a quadrature integration *** order to verify the accuracy and efficiency of the scheme,several 2D MHD test problems are *** result of MHD smooth wave problem shows third-order convergence of the *** results of the other MHD test problems show that the method can enhance the solution quality by comparing with the original second-order CESE scheme.

关键词： CESE method third-order MHD equations

PROGRESS IN HELIOSPHERIC PHYSICS

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

空间科学学报 2002年第Z1期22卷 64-80页

作者： feng xueshang Center for Space Science and Applied Research The Chinese Academy of Sciences Beijing 100080 P.R. China

This is an overview of progresses in heliospheric physics made in China in the period of June, 2000 to May, 2002. The report is focused on theoretical studies,modelling and observational analysis of interplanetary physical phenomena, and consists of five sections: the acceleration and heating of the solar wind, corona structures, coronal mass ejections, magnetic reconnection phenomena, and in terplanetary transient phenomena. The main achievements made recently by Chinese scientists in related areas are simply listed in corresponding sections without any priority, only certain editorial consideration.

关键词： Solar wind acceleration, Coronal mass ejection, Interplanetary,Transient phenomena

An asynchronous and parallel time-marching method: Application to three-dimensional MHD simulation of solar wind

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2009年第10期52卷 2895-2902页

作者： SHEN Fang feng xueshang SONG WenBin SIGMA Weather Group State Key Laboratory for Space WeatherCenter for Space Science and Applied ResearchChinese Academy of SciencesBeijing 100190China

An asynchronous and parallel time-marching method for three-dimensional (3D) time-dependent magnetohydrodynamic (MHD) simulation is used for large-scale solar wind simulation. It uses different local time steps in the corona and the heliosphere according to the local Courant-Friedrichs-Levy (CFL) conditions. The solar wind background with observed solar photospheric magnetic field as input is first presented. The simulation time for the background solar wind by using the asynchronous method is <1/6 of that by using the normal synchronous time-marching method with the same computation precision. Then, we choose the coronal mass ejection (CME) event of 13 November, 2003 as a test case. The time-dependent variations of the pressure and the velocity configured from a CME model at the inner boundary are applied to generate transient structures in order to study the dynamical interaction of a CME with the background solar wind flow between 1 and 230 Rs. This time-marching method is very effective in terms of computation time for large-scale 3D time-dependent numerical MHD problem. In this validation study, we find that this 3D MHD model, with the asynchronous and parallel time-marching method, provides a relatively satisfactory comparison with the ACE spacecraft obser- vations at L1 point.

关键词： asynchronous parallel MHD simulation CME

Recent progress in MHD simulations of the solar-terrestrial connection

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2015年第12期58卷 2212-2213页

作者： feng xueshang ZUO PingBing SIGMA Weather Group State Key Laboratory of Space Weather National Space Science CenterChinese Academy of Sciences

In recent years,considerable efforts on Magnetohydrodynamic(MHD)simulation have been made to better understand the solar-terrestrial connection,*** propagation and evolution of solar wind and solar storm as well as their effects on terrestrial *** paper briefly reviews these works based on the selected publications during 2013–2014 that cover the solar and solar wind model,solar windMoon interaction model,solar wind-magnetosphere coupling model,and magnetospheric model,etc.

关键词： MHD数值模拟太阳风暴地球系统连线磁流体动力学交互模型耦合模型太阳能

Splitting Based Scheme for Three-dimensional MHD with Dual Time Stepping

在线全文

学校读者我要写书评

暂无评论

空间科学学报 2015年第1期35卷 9-17页

作者： FU Huazheng feng xueshang State Key Laboratory for Space Weather Center for Space Science and Applied ResearchChinese Academy of Sciences University of Chinese Academy of Sciences

A new hybrid numerical scheme of combining an E-CUSP(Energy-Convective Upwind and Split Pressure) method for the fluid part and the Constrained Transport(CT) for the magnetic induction part is *** order to avoid the occurrence of negative pressure in the reconstructed profiles and its updated value,a positivity preserving method is ***,the MHD equations are solved at each physical time step by advancing in pseudo *** use of dual time stepping is beneficial in the computation since the use of dual time stepping allows the physical time step not to be limited by the corresponding values in the smallest cell and to be selected based on the numerical accuracy *** newly established hybrid scheme combined with positivity preserving method and dual time technique has demonstrated the accurateness and robustness through numerical experiments of benchmark problems such as the 2D Orszag-Tang vortex problem and the3 D shock-cloud interaction problem.

关键词： Splitting based scheme Three-dimensional MHD Dual time stepping

Observations of the field-aligned residual flow inside magnetic cloud structure

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2009年第9期52卷 2555-2566页

作者： LI HuiJun feng xueshang ZUO PingBing XIE YanQiong SIGMA Weather Group State Key Laboratory for Space WeatherCenter for Space Science and Applied ResearchChinese Academy of SciencesBeijing 100190China Graduate University of the Chinese Academy of Sciences Beijing 100039China Institute of Meteorology PLA University of Science and TechnologyNanjing 211101China

In this paper,we report two MC events observed by WIND spacecraft with good examples of fieldaligned residual flow inside the MC structure. For both events,the co-moving frames are determined through the deHoffman-Teller (HT) analysis and the axial orientations are inferred by the newly developed minimal residue (MR) method. The nature coordinate system for both events are constructed with velocity of the HT frame and the inferred MC axis,the field and flow remaining in the HT frame are analyzed at this coordinate system. As a result,we find that the residual flows in the co-moving HT frame of the two MC events are almost anti-parallel to the helical magnetic field. We speculate that the field-aligned residual flows are large scale coherent hydrodynamic vortices co-moving with the MCs at the supersonic speed near 1 AU. Data analyses show that the event in slow ambient solar wind is expanding at 1 AU and another one in fast solar wind does not show apparent expansion. Proton behaviors for both events are quasi-isothermal. Accelerated HT analysis shows that both events have no suitable HT frame with constant accelerations,which suggests that both events may be moving at the constant speed near 1 AU under the assumptions of the HT analysis. For both events,the ratio of the dynamic pressure to the magnetic pressure is larger than that of the thermal pressure to magnetic pressure,which suggests that the dynamic effects due to the plasma flows remaining in the co-moving HT frame are more important than the thermal effects in the study of MC evolution and propagation.

关键词： interplanetary medium solar wind magnetic cloud (MC) Sun:coronal mass ejections (CMEs)

GPU-accelerated computing of three-dimensional solar wind background

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2013年第11期56卷 1864-1880页

作者： feng xueshang ZHONG DingKun XIANG ChangQing ZHANG Yao SIGMA Weather Group State Key Laboratory for Space Weather Center for Space Science and Applied ResearchChinese Academy of Sciences

High-performance computational models are required to make the real-time or faster than rea^-time numerical prediction of adverse space weather events and their influence on the geospace environment. The main objective in this article is to explore the application of programmable graphic processing units （GPUs） to the numerical space weather modeling for the study of solar wind background that is a crucial part in the numerical space weather modeling. GPU programming is realized for our Solar-Interplanetary-CESE MHD model （SIP-CESE MHD model） by numerically studying the solar corona/interplanetary so- lar wind. The global solar wind structures are obtained by the established GPU model with the magnetic field synoptic data as input. Meanwhile, the time-dependent solar surface boundary conditions derived from the method of characteristics and the mass flux limit are incorporated to couple the observation and the three-dimensional （3D） MHD model. The simulated evolu- tion of the global structures for two Carrington rotations 2058 and 2062 is compared with solar observations and solar wind measurements t^om spacecraft near the Earth. The MHD model is also validated by comparison with the standard potential field source surface （PFSS） model. Comparisons show that the MHD results are in good overall agreement with coronal and interplanetary structures, including the size and distribution of coronal holes, the position and shape of the streamer belts, and the transition of the solar wind speeds and magnetic field polarities.

关键词： space weather modeling SIP-CESE MHD model GPU computing

Study of Solar Corona in China

在线全文

学校读者我要写书评

暂无评论

空间科学学报 2006年第Z1期26卷 79-89页

作者： feng xueshang ZHAO Xinhua State Key Laboratory for Space Weather Center for Space Science and Applied Research Chinese Academy of Sciences Beijing 100080 China State Key Laboratory for Space Weather Center for Space Science and Applied Research Chinese Academy of Sciences Beijing 100080 China

Considerable progress for the study of solar corona physics has been achieved by China's space physics community. It involves the theoretical study of coronal process of solar active phenomena, solar wind origin, acceleration of solar wind and coronal mass ejections, observational and numerical study of these problems and prediction methods of solar eruptive activities (such as flares/CMEs). Here is a brief summary of the progress in this area. Main progress is put upon the following three topics: corona and solar wind, numerical method, prediction method.

关键词： Corona and solar wind, Numerical method, Prediction method

Interplanetary Physics Research in China:2006—2008

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

空间科学学报 2008年第5期28卷 444-453页

作者： WANG Chi feng xueshang State Key Laboratory of Space Weather Center for Space Science and Applied Research Chinese Academy of Sciences Beijing 100190

This brief report summarized the latest advances of the interplanetary physics research in China during the period of 2006—2007,made independently by Chinese space physicists and through international *** report cove... 详细信息

关键词：行星太阳系物理研究空间研究