Multiphysics Modeling Using COMSOL v.4-02.pdf

【实例简介】
comsol的书
184 CHAPTER 4 2D MODELING Geoml/AC/DC Module- Conductive Media DC lende). Hu_EFfec I moh 日●t:x自△△4日=日9户haaa⊙ 回 nu eneg i mh 912e3.3981e3 厂 EOUAL SNAP I FIGURE 4.103 2D Hall_Effect_1 model surface voltage distribution plot(2T), with contour lines Cross-Section Plot Parameters ener al Line/Exu usiun Puint Plot typ O Line/Extrusion plot O Point plot Solutions to use Solution at angle (phase) Select via areas Frame 345G78 Times. New figure a Keep current plot M Display cross section in main axes Cole Smoothin Title/Axis ∈Hep(Apy(canc∈ok I FIGURE 4.104 2D Hall_Effect_1 model Cross-Section Plot Parameters, General page 2D Hall Effect model Considerations 185 Table 4.15 Cross-Section line data edit window Line data Value 0 X1 3e-3 Click OK. Figure 4.106 shows the voltage difference (vH between the electrode (top) and the modeled Si sample(bottom), for the line x =0. In this case VH=0.340 volt(V igh Vow=0.340V) Postprocessing Animation This solution to the 2d hall effect 1 model can also be viewed as an animation To view the solution as a movie, using the menu bar, select Postprocessing >Plot Parameters Cross-Section Plot parameters General Line/Extrusion Point Line/Extrusion plot Plot type- O Line plot Extrusion plot y-axis data Predefined quantities: Electric potential Recover Expression x-axis data Cross-section line data ⊙ 内x0:0e-3 X1:0e-3 3e-3 Line resolution 200 Multiple parallel lines Number of lines Vector with distances Line Setting..( Surface Settings. CHe)(Apy(care∈ok I FIGURE 4.105 2D Hall_Effect_1 model Cross-Section Plot Parameters, Line/Extrusion page 186 CHAPTER 4 2D MODELING Fiqure 1-COMSOL 回昌啪臀F☆的以 Electric potential [V 2.7 2.65 2.6 255 2.5 2.45 24F… 2.35 x10 I FIGURE 4.106 2D Hall_Effect_1 model plot VH Once the Plot Parameters window appears, click the Animate tab. On the Animate page select all the solutions in the Stored output times window(see Figure 4.107). Click the Start Animation button. Save this 2D Hall effect model animation by clicking on the disk icon on the player screen alternatively, you can play the file movie 4 he 1. avi that was supplied with this book First variation on the 2d hall effect model This model reflects a closer approach to the construction of a specimen as would be constructed from a silicon wafer. In this model both si end contacts and side contacts have been added, as would be the case for a fabricated Si sample To start building the Hall_Effect_2 model, activate the COMsOL Multiphysics software. In the Model Navigator select"2D from the space dimension pull-down list. Select AC/DC Module> Statics> Conductive Media DC. click the Multiphysics button, and then click the add button See Figure 4.108 Click the application Mode Properties button. Select"Onfrom the Weak con straints pull-down list. Select"Non-ideal from the Constraint type pull-down list. See Figure 4.109. Click OK 2D Hall Effect model Considerations 187 Plot Parameters Principal Streamline Particle Tracing Max/Min D ariosto Movie settings Solutions to use Output type Select via: File type Width (in pixels): 640 Height(in pixels) 480 Frames per second Advanced. 0.8 Static/ Eigenfunction animation mes Cycle type Full harmonic Number of frames: 11 三 Reverse direction O Use camera settings from main window Start Animation ∈Hep)(Apy Canc e I FIGURE 4.107 2D Hall Effect 1 model animation Plot Parameters window 188 CHAPTER 4 2D MODELING Model Navigator CNew Model Library User Models Open Settings Space dimension: Multiphysics Add R emv 口 Application Modes 回 COMSOL Multiphysics Geoml(2D) gAC/DC Module L Conductive Media DC (emdc statics Conductive Media D Electrostatics Electrostatics, Generalized Magnetostatics Quasi-Statics, Electric Dependent variables: V Quasi-Statics, Magnetic Application Mode Propertie. Electro-Thermal Interaction Add Geometry. Add Frame Dependent variables V2 Ruling application mode: Application mode name: emdc2 Conductive Media DC (emdc) Element: Lagrange-Quadra. Multiphysics Help Cancel ∈oK FIGURE 4.108 Multiphysics Model Navigator window ooO Application Mode Properties Properties Default element type: Lagrange -Quadratic Weak constraints: On Constraint type Non-ideal Help Cancel OK I FIGURE 4.109 Application Mode Properties window 2D Hall Effect model Considerations 189 Constants N me Expression Value Description sigma 1.04e3[S/m) 10405/m Silicon conductivity 125e-4[mA3/C (1. 25e-4)[m/(s A) Hall coefficient 0.1T 0.1T Magnetic field coeff sigmal/(1+(sigmaRh")2)1039.82427(S/m) Conductivity anisotropy 2 50V 5 Applied voltage t_ Si 1.0e-3(m) 0.001m Silicon thickness coeff sigma*Rh*Bz 0.013[1 Conductivity anisotropy 1 s11 coeff 103982427s/m Conductivity matrix term 11 12 coeff*coeff 13.517716/m Conductivity matrix term 12 521- coeff° coeff1l -13.517716S/m Conductivity matrix term 21 522 coeff 103982427{5/m Conductivity matrix term 22 Help Apply Ca OK I FIGURE 4.110 2D Hall Effect 2 model Constants edit window Constants USing the menu bar, select Options>Constants In the Constants edit window, enter the information shown in Table 4. 16; also see Figure 4.110. Click OK 2D Hall Effect Geometry Using the menu bar, select Draw> Specify Objects> Rectangle. Enter a width of 1. 8e-2, and a height of 6e-3 Select "Base: Corner"x and set equal to-ge-3 and y equal to-3e-3 in the rectangle edit window See Figure 4.111 Click OK, and then the click the Zoom extents button See Figure 4. 112 Table 4.16 Constants edit window Name Expression Description sigman 1.04e3|Sm] Silicon conductivity Rh 125e-4[m^3/C] Hall coefficient 0.1[T Magnetic field coeff igmao/(1+(sigma*Rh*BZ)2) Conductivity anisotropy 2 Applied voltage 1.0e3[m] Silicon thickn coeff sigma*Rh*BZ Conductivity anisotropy 1 Conductivity matrix term 11 s12 coeffi米 coeff1 Conductivity matrix term 12 - coeff“ coeff1 Conductivity matrix term 21 s22 coeff Conductivity matrix term 22 190 CHAPTER 4 2D MODELING Rectangle Size Rotation angle Width: 1.8e-2 0 (degrees) leight: 6e-3 Position Base: Corner Style Solid -9e-3 Name: Rl y 3e-3 Help Apply Cancel OK I FIGURE 4.111 2D Hall_Effect_2 model Rectangle edit window CoMsoMOl C-Ceoml/AC/DC Module- Coneuctne Veda D D日at:x的△△A日4=日9P;:aMa⊙9 口虑 +1 日 Shed coMot Masel fie Ha, tartt lmwh Adene redange wh ubel R1 GRID EQUAL SNAP DIALOG MULT SOUD I FIGURE 4.112 2D Hall_Effect_2 model rectangle geometry 2D Hall Effect model Considerations 191 Table 4.17 Rectangle Edit Window Rectangle Number Width Height Base x Location y Location 2e-3 1e-3 orner 1e-3 3e3 234 2e-3 Cccc rner -1e-3 -4e3 1e-3 orner 1e-2 3e3 1e-3 6e-3 orner 9e-3 3e-3 In this model, rectangles will be added to the boundary of the rectangle to define the location of the positions of the contacts and the floating contacts. Using the menu bar, select Draw>specify objects> Rectangle In the draw> specify objects Rectangle edit window, individually create each of the rectangles shown in Table 4.17 y selecting the window, entering the data, and then clicking OK. The final geometry with all four added rectangles is shown in Figure 4.114 Click the Zoom Extents button. Select Draw> Create Composite object. Select all of the rectangles verify that the keep interior boundaries check box is checked see Figure 4.113. Click OK. Figure 4. 114 shows the composite object. NoTe The contact rectangles are added to the boundary of the first rectangle so that the contacts and the floating contacts are precisely defined 2D Hall Effect Subdomain Settings Using the menu bar, select Physics> Subdomain Settings Select subdomains 1, 3, 4 and 5 in the Subdomain selection window. Enter t_ Si in the d (thickness )edit window. Create Composite Object Object type Shortcuts Union O Curves Cancel Intersection O Points ply Select all Help Object selection: Set formula: R1+R2+R3+R4+R5 M Keep interior boundaries R4 Repair tolerance:1.0E-4 I FIGURE 4. 113 2D Hall Effect 2 model, Create Composite Object window 【实例截图】
【核心代码】