检索结果-南通市图书馆

Calibration of discrete element modeling: Scaling laws and dimensionless analysis

Particuology 2022年第3期20卷 55-62页

作者： Yucang Wang Peter Mora Yunpei Liang State Key Laboratory of Coal Mine Disaster Dynamics and Control Chongqing UniversityChongqing 400044China College of Petroleum Engineering and Geosciences King Fahd University of Petroleum and MineralsSaudi Arabia

In this paper,dynamic similarity conditions are derived for discrete element simulations by non-dimensionalising the governing *** conditions must be satisfied so that the numerical model is a good representation of the physical *** a pure mechanical system,if three independent ratios of the corresponding quantities between the two models are set,then the ratios of other quantities must be chosen according to the similarity *** scalability of linear and non-linear contact laws is also *** tests of 3D uni-axial compression are carried out to verify the theoretical *** example is presented to show how to calibrate the model according to laboratory data and similarity ***,it is impossible to reduce computer time by scaling up or down certain parameters and continue to uphold the similarity *** results in this paper provide guidelines to assist discrete element modelers in setting up the model parameters in a physically meaningful way.

关键词： Discrete element method dimensionless analysis Dynamic similarity Parameter calibration ESyS_Particle

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

Dual-wavelength flash Raman mapping method for measuring thermal diffusivity of the suspended nanowire

引用

Science China(Technological Sciences) 2020年第5期63卷 748-754页

作者： HU YuDong FAN AoRan WANG HaiDong MA WeiGang ZHANG Xing Key Laboratory for Thermal Science and Power Engineering of Ministry of Education Department of Engineering MechanicsTsinghua UniversityBeijing 100084China

In this paper,we present a dual-wavelength flash Raman(DFR)mapping method for measuring the thermal diffusivity of a suspended nanowire.A heating pulse is used to heat the nanowire sample,and a probing pulse of different wavelength is used to measure the increase in *** laser absorption coefficient can be eliminated by normalization,and the thermal diffusivity of the sample can be extracted from the normalized temperature *** infinite heat conduction model is used in this method to avoid the influence of boundary thermal *** changing the position of the probing laser center,the measurement sensitivity of thermal diffusivity can be further *** position of maximum sensitivity is influenced by the thermal diffusivity of the nanowire,width of the heating pulse,radius of the heating laser spot,and characteristic length of the *** comprehensively analyze the influences of the various parameters,obtain the best measurement conditions,and attain maximum sensitivity,we propose a dimensionless physical model to analyze the heat conduction of the suspended *** on the analysis of the best dimensionless parameters,the corresponding appropriate measurement conditions can be *** analysis shows that when the radius of the heating laser spot is 1%of the length of the nanowire,the sensitivity of the DFR mapping method can be more than four times that of the concentric DFR method for measuring the thermal diffusivity of the nanowire.

关键词： DFR mapping method thermal diffusivity nanowire dimensionless analysis

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

Characteristics of non-Darcy flow in low-permeability reservoirs

引用

Petroleum Science 2011年第1期8卷 55-62页

作者： Yao Yuedong Ge Jiali Key Laboratory of Petroleum Engineering of the Ministry of Education China University of PetroleumBeijing 102249 China

Well testing is recognized as an effective means of accurately obtaining the formation parameters of low-permeability reservoirs and effectively analyzing the *** test models must comply with the particular characteristics of flow in low-permeability reservoirs in order to obtain reasonable well test *** present,non-Darcy flow in low-permeability reservoirs is attracting much *** this study,displacement tests were conducted on typical cores taken from low-permeability *** dimensionless variables were introduced to analyze the collected experimental *** results of the dimensionless analysis show whether non-Darcy flow happens or not depends on the properties of fluid and porous media and the pressure *** combination of the above three parameters was named as dimensionless criteria coefficient（DCC）.When the value of the DCC was lower than a critical Reynolds number（CRN）,the flow could not be well described by Darcy＇s law（so-called non-Darcy flow）,when the DCC was higher than CRN,the flow obeyed Darcy＇s ***,this paper establishes a transient mathematical model considering Darcy flow and non-Darcy flow in low-permeability reservoirs,and proposes a methodology to solve the *** solution technique,which is based on the Boltzmann transformation,is well suited for solving the flow model of low-permeability *** on the typical curves analysis,it was found that the pressure and its derivative curves were determined by such parameters as non-Darcy flow index and the flow *** results can be used for well test analysis of low-permeability reservoirs.

关键词： Low-permeability non-Darcy flow dimensionless analysis transient flow well testing

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

Theory of Volumetric Moving Dislocation in Poroelastic Halfspace and Characterization of Magma Intrusion Events

引用

Journal of China University of Geosciences 2005年第1期16卷 58-65页

作者： OuyangZhihua ElsworthDerek ShengJianlong DepartmentofMiningEngineering WuhanUniversityofScienceandTechnologyWuhan430081China StateCollege PennsylvaniaStateUniversityPA16801USA

The undrained change in pore fluid pressure that accompanies dike intrusion may be conveniently represented as a moving volumetric dislocation. The concept of a dilation center was developed to represent the field of undrained pressure change in a saturated linear elastic medium. Since instantaneous pore fluid pressures can be developed to a considerable distance from the dislocation, monitoring the rate of pressure generation and subsequent pressure dissipation in a fully coupled manner enables certain characteristics of the resulting dislocation to be defined. The principal focus of this study is the application of dislocation based methods to analyze the behavior of the fluid pressure response induced by intrusive dislocations in a semi infinite space, such as dike intrusion, hydraulic fracturing and piezometer insertion. Partially drained pore pressures result from the isothermal introduction of volumetric moving pencil like dislocations described as analogs to moving point dislocation within a semi infinite saturated elastic medium. To represent behavior within the halfspace, an image dislocation is positioned under the moving coordinate frame fixed to the front of the primary moving dislocation, to yield an approximate solution for pore pressure for constant fluid pressure conditions. Induced pore pressures are concisely described under a minimum set of dimensionless parameter groupings representing propagation velocity, and relative geometry. Charts defining induced pore fluid pressure at a static measuring point provide a meaningful tool for determining unknown parameters in data reduction. Two intrusive events at Krafla, Iceland are examined using the type curve matching techniques. Predicted parameters agree favorably with field data.

关键词： volumetric dislocation magma intrusion dimensionless analysis pore pressure.

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

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

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

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：