检索结果-南通市图书馆

Multiscale RBF-based central high resolution schemes for simulation of generalized thermoelasticity problems

Frontiers of Structural and Civil Engineering 2019年第2期13卷 429-455页

作者： Hassan YOUSEFI Alireza TAGHAVI KANI Iradj MAHMOUDZADEH KANI School of Civil Engineering College of EngineeringUniversity of TehranTehran11155-4563Iran Department of Civil Engineering Arak University of TechnologyArak***Iran

In this study, average-interpolating radial basis functions (RBFs) are successfully integrated with central high-resolution schemes to achieve a higher-order central method. This proposed method is used for simulation of generalized coupled thermoelasticity problems including shock (singular) waves in their solutions. The thermoelasticity problems include the LS (systems with one relaxation parameter) and GN (systems without energy dissipation) theories with constant and variable coefficients. In the central high resolution formulation, RBFs lead to a reconstruction with the optimum recovery with minimized roughness on each cell: this is essential for oscillation-free reconstructions. To guarantee monotonic reconstructions at cell-edges, the nonlinear scaling limiters are used. Such reconstructions, finally, lead to the total variation bounded (TVB) feature. As RBFs work satisfactory on non-unifdrm cells/grids, the proposed central scheme can handle adapted cells/grids. To have cost effective and accurate simulations, the multiresolution-based grid adaptation approach is then integrated with the RBF-based central scheme. Effects of condition numbers of RBFs, computational complexity and cost of the proposed scheme are studied. Finally, different 1-D coupled thermoelasticity benchmarks are presented. There, perfonnance of the adaptive RBF-based formulation is compared with that of the adaptive Kurganov-Tadmor (KT) second-order central high-resolution scheme with the total variation diminishing (TVD) property.

关键词： central high resolution schemes RBFs higher order accuracy generalized thermoelasticity multiresolutionbased adaptation

来源：

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

ALTERNATING DIRECTION IMPLICIT schemes FOR THE TWO-DIMENSIONAL TIME FRACTIONAL NONLINEAR SUPER-DIFFUSION EQUATIONS

引用

Journal of Computational Mathematics 2019年第3期37卷 297-315页

作者： Jianfei Huang Yue Zhao Sadia Arshad Kuangying Li Yifa Tang College of Mathematical Sciences Yangzhou UniversityYangzhou 225002China LSEC ICMSECAcademy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China School of Mathematical Sciences University of Chinese Academy of SciencesBeijing 100049China COMSATS Institute of Information Technology LahoTePakistan McDougall School of Petroleum Engineering The University of TulsaTulsaOK 74104USA

As is known,there exist numerous alternating direction implicit(ADI)schemes for the two-dimensional linear time fractional partial differential equations(PDEs).However,if the ADI schemes for linear problems combined with local linearization techniques are applied to solve nonlinear problems,the stability and convergence of the methods are often not clear.In this paper,two ADI schemes are developed for solving the two-dimensional time fractional nonlinear super-diffusion equations based on their equivalent partial integrodifferential equations.In these two schemes,the standard second-order central difference approximation is used for the spatial discretization,and the classical first-order approximation is applied to discretize the Riemann-Liouville fractional integral in time.The solvability,unconditional stability and L2 norm convergence of the proposed ADI schemes are proved rigorously.The convergence order of the schemes is 0(τ+hx^2+hy^2),where τ is the temporal mesh size,hx and hy are spatial mesh sizes in the x and y directions,respectively.Finally,numerical experiments are carried out to support the theoretical results and demonstrate the performances of two ADI schemes.

关键词： Time fractional super-diffusion equation Nonlinear system ADI schemes Stability Convergence

来源：

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

SENSITIVITY OF THE WEATHER RESEARCH AND FORECASTING MODEL TO RADIATION schemes IN CHINA

引用

Journal of Tropical Meteorology 2019年第2期25卷 201-210页

作者：王永立冯锦明郑子彦靳少非 CAS Key Laboratory of Regional Climate-Environment for Temperate East Asia Institute of Atmospheric Physics Chinese Academy of Sciences Institute of Environment Energy and Sustainability The Chinese University of Hong Kong Department of Geography Ocean College Minjiang University

Results of one-year simulations using the Weather Research and Forecasting(WRF) model, with the use of different radiation schemes(RRTM, RRTMG, CAM, New Goddard and Goddard), are evaluated for China. The observations used in the model assessment include station data from the China Meteorological Administration, 14 flux field sites arranged in a coordinated observation network, and Global Land Data Assimilation System(GLDAS) data.Specifically, based on a Taylor diagram, the temperature differences between the radiation schemes are small, and the best annual mean spatial pattern and average value for China as a whole is produced by RRTMG. For the rainfall and net radiation annual mean simulation, the New Goddard and CAM schemes present better results than the RRTMG scheme. With respect to low cloud cover, all the schemes have similar reproduction without high cover on east of Tibet Plateau. Overall, the New Goddard and CAM schemes are suitable for longtime simulation without nesting and nudging options.

关键词： radiation schemes WRF regional climate

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Numerical Investigation of Different Airflow schemes in a Real Operating Theatre

引用

Journal of Biomedical Science and Engineering 2015年第2期8卷 73-89页

作者： Carla Balocco Giuseppe Petrone Giuliano Cammarata Department of Industrial Engineering University of Firenze Firenze Italy Department of Industrial Engineering University of Catania Catania Italy

A study on performances of different ventilation schemes provided by vertical and horizontal uni-directional air flow was carried out in a standard orthopaedic operating theatre (OT). Starting from our previous studies of a real OT under operating use conditions, in this research different air flow configurations, considering some air curtain solutions on the ceiling and at the sliding door always assumed to be open as a basic boundary condition, were investigated by numerical simulations. Indoor air quality (IAQ) indexes and thermal comfort parameters, deduced from simulation results were calculated and discussed referring to the best performance and efficacy between the air flow schemes to contrast the incorrect use conditions of the OT. Referring to the studied schemes, the reciprocal comparison emphasizes that a successful outcome in preventing surgical site infection can depend as much on resolving human factors (i.e. operational use conditions, door opening/closing), as on overcoming physical and technical obstacles.

关键词： Real Operating Theatre Ventilation schemes Air Curtain IAQ Thermal Comfort

来源：

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

Accuracy and Computational Cost of Interpolation schemes While Performing <i>N</i>-Body Simulations

引用

American Journal of Computational Mathematics 2014年第5期4卷 446-454页

作者： Shafiq Ur Rehman Department of Mathematics The University of Auckland Auckland New Zealand Department of Mathematics University of Engineering and Technology Lahore Pakistan

The continuous approximations play a vital role in N-body simulations. We constructed three different types, namely, one-step (cubic and quintic Hermite), two-step, and three-step Hermite interpolation schemes. The continuous approximations obtained by Hermite interpolation schemes and interpolants for ODEX2 and ERKN integrators are discussed in this paper. The primary focus of this paper is to measure the accuracy and computational cost of different types of interpolation schemes for a variety of gravitational problems. The gravitational problems consist of Kepler’s two-body problem and the more realistic problem involving the Sun and four gas-giants—Jupiter, Saturn, Uranus, and Neptune. The numerical experiments are performed for the different integrators together with one-step, two-step, and three-step Hermite interpolation schemes, as well as the interpolants.

关键词： N-Body Simulation Integrators Interpolation schemes

来源：

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

The Simulating of Power Electronics Systems with the Use of Explicit Numerical schemes

引用

Applied Mathematics 2013年第1期4卷 223-227页

作者： Yuri Tanovitski Gennady Kobzev Tomsk State University of Control Systems and Radioelectronics Tomsk Russia

Automated simulating of power electronics systems is currently performed by means of nodal analysis method combined with implicit numerical integration schemes. Such method allows to find transient solutions, even when the integrated system is stiff, however, it leads to some difficulties when simulating big systems and sometimes to the deterioration of computations quality, that is reflected in decrease in accuracy, oscillations of solutions, which are not present in the initial model. This paper analyzes the shortcomings of this approach, and proposes to apply explicit numerical schemes with stability control on the integration step and with reduction of some of state variables. A brief description of the method of finding transient solutions and an example of the analysis are also given in the present paper.

关键词： Transient Analysis Implicit Explicit Numerical schemes Power Electronics

来源：

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

Analysis of Extreme Rainfall Event with Different Microphysics and Parameterization schemes in WRF Model

引用

Positioning 2018年第1期9卷 1-11页

作者： Hiren Satishkumar Lekhadiya Ranjan Kumar Jana Department of Applied Mathematics & Humanities Sardar Vallabhbhai National Institute of Technology Surat India

In the present study, the imitation of heavy rainfall event which occurred over Jharkhand during 18 August 2016 was taken as a case study. Weather Research and Forecasting (WRF) model has been utilized for this study. National Centers for Environmental Prediction (NCEP) analysis data is compared with GSMaP data with different combination of physical parameterization scheme like microphysics (MP) and cumulus parameterization (CP). In the present study, three MP schemes: Kessler scheme, Lin et al. scheme and WRF Single-moment 6-class scheme with combination of three CP schemes: Betts-Miller-Janjic scheme, Multi-scale Kain-Fritsch scheme and New simplified Arakawa-Schubert scheme have been used. The model predicted humidity, temperature and precipitation were compared with the GSMaP product. The model nicely depicted the cloud pattern and recognized the rain event spatially. The obtained result shows that the model overestimates the precipitation for all the schemes.

关键词： Data Assimilation NWP Model Prediction Parameterization schemes

来源：

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

Assessing Weather Research and Forecasting (WRF) Model Parameterization schemes Skill to Simulate Extreme Rainfall Events over Dar es Salaam on 21 December 2011

引用

Journal of Geoscience and Environment Protection 2018年第1期6卷 36-54页

作者： Triphonia Jacob Ngailo Nyimvua Shaban Joachim Reuder Michel D. S. Mesquita Edwin Rutalebwa Isaac Mugume Chiku Sangalungembe Department of Mathematics University of Tanzania Dar es Salaam Tanzania Geophysical Institute University of Bergen Bergen Norway Uni Research Climate Bjerknes Centre for Climate Studies University of Bergen Bergen Norway General studies Department Dar es Salaam Institute of Technology Dar es Salaam Tanzania Department of Geography Geoinformatics and Climate Sciences Makerere University Kampala Uganda Modelling Section Tanzania Meteorological Agency Dar es Salaam Tanzania

This paper evaluates the skills of physical Parameterization schemes in simulating extreme rainfall events over Dar es Salaam Region, Tanzania using the Weather Research and Forecasting (WRF) model. The model skill is determined during the 21 December 2011 flooding event. Ten sensitivity experiments have been conducted using Cumulus, Convective and Planetary boundary layer schemes to find the best combination and optimize the WRF model for the study area for heavy rainfall events. Model simulation results were verified against observed data using standard statistical tests. The model simulations show encouraging and better statistical results with the combination of Kain-Fritsch cumulus parameterization scheme, Lin microphysics scheme and Asymmetric Convection Model 2 (ACM2) planetary boundary scheme than any other combinations of physical parameterization schemes over Dar es Salaam region.

关键词： WRF Dar es Salaam Extreme Rainfall Events Physical Parameterization schemes

来源：

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

A Comprehensive Review of Protection schemes for Distributed Generation

引用

Energy and Power Engineering 2017年第8期9卷 430-463页

作者： Umair Shahzad Sohrab Asgarpoor Department of Electrical and Computer Engineering University of Nebraska-Lincoln Lincoln NE USA

Due to the increasing demand of energy and the need for nonconventional energy sources, distributed generation (DG) has come into play. The trend of unidirectional power flow has been gradually shifting. With new technology comes new challenges, the introduction of DG into the conventional power system brings various challenges;one of the major challenges is system protection under DG sources. These sources pose a significant challenge due to bidirectional flows from DGs as well as lower fault current contribution from inverter interfaced DGs. This paper reviews existing protection schemes that have been suggested for active distribution networks. Most of these protection strategies apply only to smaller distribution systems implying that they may need to be extended to larger systems with a much higher penetration of distributed generation. In the end, a potential protection scheme has also been recommended as a future work.

关键词： Distributed Generation (DG) Energy Protection schemes Active Distribution Networks

来源：

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

High Order Central schemes Applied to Relativistic Multi-Component Flow Models

引用

Applied Mathematics 2014年第8期5卷 1169-1186页

作者： Tayabia Ghaffar Muhammad Yousaf Saira Sultan Shamsul Qamar Department of Mathematics COMSATS Institute of Information Technology Islamabad Pakistan Department of Mathematics Quaid-i-Azam University Islamabad Pakistan

The dynamics of inviscid multi-component relativistic fluids may be modeled by the relativistic Euler equations, augmented by one (or more) additional species equation(s). We use the high-resolution staggered central schemes to solve these equations. The equilibrium states for each component are coupled in space and time to have a common temperature and velocity. The current schemes can handle strong shocks and the oscillations near the interfaces are negligible, which usually happens in the multi-component flows. The schemes also guarantee the exact mass conservation for each component, the exact conservation of total momentum, and energy in the whole particle system. The central schemes are robust, reliable, compact and easy to implement. Several one- and two-dimensional numerical test cases are included in this paper, which validate the application of these schemes to relativistic multi-component flows.

关键词： Multi-Component Flows Relativistic Euler Equations Central schemes Higher Order Accuracy

来源：

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

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：