COMSOL-Multiphysics中各常用內置參量

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. 具有保留名稱的內置變量摘要本節(jié)概述了由基礎COMSOL語言定義的以下類別的內置元素：常量變量功能這些語言元素是內置的或用戶定義的。止匕外，還有不能由用戶定義的運算符， 以及始終由用戶定義的表達式。ABOUT RESERVED NAMES關于預留名稱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.內置變量具有保留名稱，用戶無法重新定義。不建議對用戶定義的變量，參數 或函數使用保留的變量名。對于一些最常見的保留變量名稱，例如pi，i和j， 輸入名稱變?yōu)槌壬?，如果選擇文本字符串，則會得到工具提示消息。保留的

5、函 數名稱僅作為函數名保留，這意味著此類名稱可用于變量和參數名稱，反之亦 然。下表列出了大多數內置元素，因此列出了這些保留名稱。CONSTANTS AND PARAMETERS 常量和參數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.有三種不同類型的常數：內置的數學和數值常數，內置的物理常數和參數。參 數是用戶定義的常量，可以隨參數掃描而變化。常量是標量值。下表列出了 內置物理常量。常量和參數可以有單位。BUILT-IN PHYSICAL CONSTANTS 內置物理常數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(自由空間的阻抗)me_constElectron mass電子質量e_constElementary charge 元電荷F_constFaraday constant法拉第常數alpha_constFine-structure constant 精細結構常數G

8、_constGravitational constant 萬有引力常量V_m_constMolar volume of ideal gas (at 273.15 K and 1 atm) 理想氣體的摩爾體積(在273.15K和1atm下)mn_constNeutron mass中子質量mu0_constPermeability of vacuum (magnetic constant) 真空的磁導率(磁常數)epsilon0_constPermittivity of vacuum (electric constant)真空介電常數(電常數)h_constPlanck,s constant 普朗

9、克常數hbar_constPlanck,s constant over 2 pi 超過 2 pi 的普朗克常數mp_constProton mass質子質量c_constSpeed of light in vacuum 真空中的光速sigma_constStefan-Boltzmann constant斯帝芬一玻爾茲曼常數R_constUniversal gas constant 通用氣體常數b_constWien displacement law constant 維恩位移常數BUILT-IN MATHEMATICAL FUNCTIONS 內置數學函數These functions do n

10、ot have units for their input or output arguments.這些函數沒有 用于其輸入或輸出參數的單位。TABLE 5-13: BUILT-INMATHEMATICALFUNCTIONSNAMEDESCRIPTIONabsAbsolute value 絕對值acosInverse cosine （in radians）逆余弦（以弧度表示）acoshInverse hyperbolic cosine 反雙曲余弦acotInverse cotangent (in radians)反余切(單位為弧度)acothInverse hyperbolic cotange

11、nt 反雙曲余切acscInverse cosecant (in radians)逆余弦(以弧度表示)acschInverse hyperbolic cosecant 反雙曲余割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 反雙曲正割asinInverse sine (in radians)反正弦(以弧度表示)asinhInverse hyperbolic sine 反雙曲正弦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 反雙曲正切besseljBessel function of the first kind 第一類貝塞爾函數besselyBessel function of the second kind 第二類貝塞爾函數besseliModified Bessel function of the first kind 第一類修改的貝塞爾函數besselkModified Bessel functio

13、n of the second kind 第二類修改的貝塞爾函數ceilNearest following integerconjComplex conjugate 復共軛cosCosine余弦coshHyperbolic cosine 雙曲余弦cotCotangent 余切cothHyperbolic cotangent 雙曲余切cscCosecant 余割cschHyperbolic cosecant 雙曲余割erfError function 誤差函數expExponential 指數floorNearest previous integergammaGamma function 伽馬函

14、數imagImaginary part 虛部logNatural logarithm 自然對數log10Base-10 logarithmlog2Base-2 logarithmmaxMaximum of two argumentsminMinimum of two argumentsmodModulo operator 模運算符psiPsi function and its derivatives ”函數及其導數rangeCreate a range of numbers 創(chuàng)建一個數字范圍realReal part 實部roundRound to closest integer四舍五入為最接

15、近的整數secSecant割線sechHyperbolic secant 雙曲正割signSignum function 符號函數sinSine正弦sinhHyperbolic sine 雙曲正弦sqrtSquare root 平方根tanTangent雙曲正切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.下表總結了通常在所有COMSOL模型中用到的內置變量和常量。例如，一些僅 在某些幾何形狀或在瞬態(tài)模型中可用。這些變量名稱是保留的名稱，在參數和 變量的設置窗口中顯示為橙色TABLE 5-14: BUILT-INVARIABLES ANDCONSTANTSN

17、AMEDESCRIPTIONTYPEtTime.時間Scalar標量freqFrequency.頻率ScalarlambdaEigenvalues.特征值ScalarphasePhase angle.相位角ScalarnumberofdofsNumber of degrees of freedom.自由度數Scalarx, y, z, r, X, Y Z, RPosition.位置Field域s, s1, s2Edge/surface parameters.邊/面參數Fieldn, nx, ny, nz, nrEdge/surface normals.邊/面法線Fieldtx, ty, tz,

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

19、element edge).局部網格兀素大小(最長元素 邊的長度)FielddomThe domain number, boundary number, edge number, or point number.域名，邊界號，邊緣 號或點號FieldmeshtypeMesh type index for the mesh element; this is the number of edges in the element.網格元素 的網格類型索引;這是元素中的邊的數量FieldmeshelementMesh element number.網格元素數FieldmeshvolVolume of

20、the (linearized) mesh element.(線 性化)網格元素的體積FielddvolVolume scale factor variable; this is the determinant of the Jacobian matrix for the mapping from local (element) coordinates to global coordinates.體積比例因子變量;這是用 于從局部(元素)坐標到全局坐標的映射的 雅可比矩陣的行列式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.網格質量測量在0 (質量 差)和1 (完美質量)之間。網格元素質量 的絕對值基于對應于元素的每個角的單形 的內切圓或外接圓或球的半徑的比率。負值 意味著與網格元素頂點的編號慣例矛盾，然 后該元素被稱為反向元素FieldimplexreldetjacDeterminant of the Jacobian matrix for theFieldmapping from the straight mesh element to the possibly curved ele

23、ment used when solving.Jacobian矩陣的決定因素，用于從直 的網格元素到解決時使用的可能彎曲的元 素的映射reldetjacminThe minimum value of the reldetjac variable in each element.每個元素中reldetjac變量的最 小值FieldlinearizedelemOne inside elements that have been linearized; zero otherwise.線性化的一個內部元素;否則 為零FieldniterCMPIteration number for nonlinear

24、 iterations.非線性迭代的迭代數Scalargmg_levelGeometric multigrid level.幾何多網格級ScalartimestepCurrent time step.當前時間步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.定義每個粒子或射 線的唯一正整數。此變量僅在使用幾何光學 接口，Ray Acoustics接口或粒子跟蹤物理接 口之一時才定義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