COMSOL-Multiphysics中各常用内置参量

1、Summary of Built-In Variables With Reserved NamesThis section is an overview of the built-in elements of the following categories as defined by the underlying COMSOL language:ConstantsVariablesFunctionsThese language elements are built-in or user-defined. In addition there are operators that cannot

2、be user-defined, and expressions, which are always user-defined. 具有保留名称的内置变量摘要本节概述了由基础COMSOL语言定义的以下类别的内置元素：常量变量功能这些语言元素是内置的或用户定义的。止匕外，还有不能由用户定义的运算符， 以及始终由用户定义的表达式。ABOUT RESERVED NAMES关于预留名称Built-in variables have reserved names, names that cannot be redefined by the user. It is not recommended to us

3、e a reserved variable name for a user-defined variable, parameter, or function. For some of the most common reserved variable names, such as pi, i, and j, the text where you enter the name turns orange and you get a tooltip message if you select the text string. Reserved function names are reserved

4、only for function names, which means that such names can be used for variable and parameter names, and vice versa. The following tables list most built-in elements and hence those reserved names.内置变量具有保留名称，用户无法重新定义。不建议对用户定义的变量，参数 或函数使用保留的变量名。对于一些最常见的保留变量名称，例如pi，i和j， 输入名称变为橙色，如果选择文本字符串，则会得到工具提示消息。保留的

5、函 数名称仅作为函数名保留，这意味着此类名称可用于变量和参数名称，反之亦 然。下表列出了大多数内置元素，因此列出了这些保留名称。CONSTANTS AND PARAMETERS 常量和参数There are three different types of constants: built-in mathematical and numerical constants, built-in physical constants, and parameters. Parameters are user-definedconstants that can vary over parameter sw

6、eeps. Constants are scalar valued. The following table lists the built-in physical constants. Constants and parameters can have units.有三种不同类型的常数：内置的数学和数值常数，内置的物理常数和参数。参 数是用户定义的常量，可以随参数扫描而变化。常量是标量值。下表列出了 内置物理常量。常量和参数可以有单位。BUILT-IN PHYSICAL CONSTANTS 内置物理常数TABLE 5-12: BUILT-INPHYSICALCONSTANTSNAMEDESC

7、RIPTION 描述g_constAcceleration of gravityN_A_constAvogadro constantk_B_constBoltzmann constantZ0_constCharacteristic impedance of vacuum (impedance of free space)真空的特性阻抗(自由空间的阻抗)me_constElectron mass电子质量e_constElementary charge 元电荷F_constFaraday constant法拉第常数alpha_constFine-structure constant 精细结构常数G

8、_constGravitational constant 万有引力常量V_m_constMolar volume of ideal gas (at 273.15 K and 1 atm) 理想气体的摩尔体积(在273.15K和1atm下)mn_constNeutron mass中子质量mu0_constPermeability of vacuum (magnetic constant) 真空的磁导率(磁常数)epsilon0_constPermittivity of vacuum (electric constant)真空介电常数(电常数)h_constPlanck,s constant 普朗

9、克常数hbar_constPlanck,s constant over 2 pi 超过 2 pi 的普朗克常数mp_constProton mass质子质量c_constSpeed of light in vacuum 真空中的光速sigma_constStefan-Boltzmann constant斯帝芬一玻尔兹曼常数R_constUniversal gas constant 通用气体常数b_constWien displacement law constant 维恩位移常数BUILT-IN MATHEMATICAL FUNCTIONS 内置数学函数These functions do n

10、ot have units for their input or output arguments.这些函数没有 用于其输入或输出参数的单位。TABLE 5-13: BUILT-INMATHEMATICALFUNCTIONSNAMEDESCRIPTIONabsAbsolute value 绝对值acosInverse cosine （in radians）逆余弦（以弧度表示）acoshInverse hyperbolic cosine 反双曲余弦acotInverse cotangent (in radians)反余切(单位为弧度)acothInverse hyperbolic cotange

11、nt 反双曲余切acscInverse cosecant (in radians)逆余弦(以弧度表示)acschInverse hyperbolic cosecant 反双曲余割argPhase angle （in出12口5）相位角（以弧度表示）asecInverse secant （in radians）反正切（以弧度表示）asechInverse hyperbolic secant 反双曲正割asinInverse sine (in radians)反正弦(以弧度表示)asinhInverse hyperbolic sine 反双曲正弦atanInverse tangent (in rad

12、ians)反正切(弧度)atan2Four-quadrant inverse tangent (in radians)四象限反 正切(以弧度表示)atanhInverse hyperbolic tangent 反双曲正切besseljBessel function of the first kind 第一类贝塞尔函数besselyBessel function of the second kind 第二类贝塞尔函数besseliModified Bessel function of the first kind 第一类修改的贝塞尔函数besselkModified Bessel functio

13、n of the second kind 第二类修改的贝塞尔函数ceilNearest following integerconjComplex conjugate 复共轭cosCosine余弦coshHyperbolic cosine 双曲余弦cotCotangent 余切cothHyperbolic cotangent 双曲余切cscCosecant 余割cschHyperbolic cosecant 双曲余割erfError function 误差函数expExponential 指数floorNearest previous integergammaGamma function 伽马函

14、数imagImaginary part 虚部logNatural logarithm 自然对数log10Base-10 logarithmlog2Base-2 logarithmmaxMaximum of two argumentsminMinimum of two argumentsmodModulo operator 模运算符psiPsi function and its derivatives ”函数及其导数rangeCreate a range of numbers 创建一个数字范围realReal part 实部roundRound to closest integer四舍五入为最接

15、近的整数secSecant割线sechHyperbolic secant 双曲正割signSignum function 符号函数sinSine正弦sinhHyperbolic sine 双曲正弦sqrtSquare root 平方根tanTangent双曲正切tanhHyperbolic tangentThe following table summarizes the built-in variables and constants that are generally available in all COMSOL models. Some are only available in c

16、ertain geometries or in time-dependent models, for example. These variable names are reserved names and appear in orange in the Settingwindows for parameters and variables.下表总结了通常在所有COMSOL模型中用到的内置变量和常量。例如，一些仅 在某些几何形状或在瞬态模型中可用。这些变量名称是保留的名称，在参数和 变量的设置窗口中显示为橙色TABLE 5-14: BUILT-INVARIABLES ANDCONSTANTSN

17、AMEDESCRIPTIONTYPEtTime.时间Scalar标量freqFrequency.频率ScalarlambdaEigenvalues.特征值ScalarphasePhase angle.相位角ScalarnumberofdofsNumber of degrees of freedom.自由度数Scalarx, y, z, r, X, Y Z, RPosition.位置Field域s, s1, s2Edge/surface parameters.边/面参数Fieldn, nx, ny, nz, nrEdge/surface normals.边/面法线Fieldtx, ty, tz,

18、 trEdge tangents.边缘切线Fieldt1x, t1y, t1z, t2x, t2y, t2zSurface tangents.表面切线Fieldun, unx, uny, unzEdge/surface upward normals.边/面向上法线Fielddn, dnx, dny, dnzEdge/surface downward normals.Fieldeps, i, j, pi, inf, Inf, nan, NaNNumerical constants.数字常量ScalarhLocal mesh element size (length of the longest

19、element edge).局部网格兀素大小(最长元素 边的长度)FielddomThe domain number, boundary number, edge number, or point number.域名，边界号，边缘 号或点号FieldmeshtypeMesh type index for the mesh element; this is the number of edges in the element.网格元素 的网格类型索引;这是元素中的边的数量FieldmeshelementMesh element number.网格元素数FieldmeshvolVolume of

20、the (linearized) mesh element.(线 性化)网格元素的体积FielddvolVolume scale factor variable; this is the determinant of the Jacobian matrix for the mapping from local (element) coordinates to global coordinates.体积比例因子变量;这是用 于从局部(元素)坐标到全局坐标的映射的 雅可比矩阵的行列式FieldqualA mesh quality measure between 0 (poor quality) a

21、nd 1 (perfect quality). The absolute value of the mesh element quality is based on the ratios of the inscribed and circumscribed circles, or spheres, radii for the si corresponding to each corner of the element. A negative value means a contradiction to the numbering convention for mesh element vert

22、ices and the element is then referred to as an inverted element.网格质量测量在0 (质量 差)和1 (完美质量)之间。网格元素质量 的绝对值基于对应于元素的每个角的单形 的内切圆或外接圆或球的半径的比率。负值 意味着与网格元素顶点的编号惯例矛盾，然 后该元素被称为反向元素FieldimplexreldetjacDeterminant of the Jacobian matrix for theFieldmapping from the straight mesh element to the possibly curved ele

23、ment used when solving.Jacobian矩阵的决定因素，用于从直 的网格元素到解决时使用的可能弯曲的元 素的映射reldetjacminThe minimum value of the reldetjac variable in each element.每个元素中reldetjac变量的最 小值FieldlinearizedelemOne inside elements that have been linearized; zero otherwise.线性化的一个内部元素;否则 为零FieldniterCMPIteration number for nonlinear

24、 iterations.非线性迭代的迭代数Scalargmg_levelGeometric multigrid level.几何多网格级ScalartimestepCurrent time step.当前时间步ScalarparticleindexA unique positive integer to define each particle or ray. This variable is only defined when using the Geometrical Optics interface, Ray Acoustics interface, or one of the part

25、icle tracing physics interfaces.定义每个粒子或射 线的唯一正整数。此变量仅在使用几何光学 接口，Ray Acoustics接口或粒子跟踪物理接 口之一时才定义ScalarparticlestatusAn integer that corresponds to the status of a particle or ray, which indicates whether the particle or ray is active or has been subjected to certain types of boundary conditions. This variable is only defined when using theScalarGeometrical Optics interface, Ray Acoustics interface, or one of the particle t