Comsol anti periodicity. This is the first blog post in a two-part series.

Comsol anti periodicity 0 Replies Last Post Jun 30, 2016, 6:51 a. My next step is to apply Bloch/Floquet periodicity to the system. In other cases use a Destination Selection subnode to control the destination. The Average strain periodicity type allows to derive homogenized elastic properties of media with a periodic structure, such as a perforated plates, porous media or composites structures. Work Plane 1 (wp1)>Difference 1 (dif1) 1 In the Work Plane toolbar, click Booleans and Partitions and choose Difference. Niels Hoekstra Is there a similar expression in COMSOL to do this in 3D? Best regards, Niels . A LSAW finite aperture device with 42o YX-cut LiTaO3 substrate was simulated in COMSOL Multiphysics®. 2 Select the object c1 only. How do you set the k vector of Floquet periodicity? Best regards. Posted Jan 31, 2018, 7:04 a. The spacing, d, is the periodicity in the plane defined by the \bf{n In the Semiconductor Module, as of version 5. This can be done using the RF or Wave Optics modules from the COMSOL product suite. For information about the Orientation of Destination section, see Orientation of Source and Destination in the COMSOL Multiphysics Reference Manual. Materials and Solid Mechanics Material Properties in the COMSOL Multiphysics Reference Manual. Periodic Condition Select a Type of periodicity : Continuity (the default) to make the dependent variables equal, or Antiperiodicity to make them antiperiodic: u ( x 0 ) = − u ( x 1 ) . As the array of cells is a continuous structure, displacement continuity must be satisfied across the boundaries between the cells. If required, activate periodic conditions on more than two boundaries, in which case the Periodic By using the compactness and non-periodicity of ultrasonic array elements arranged along a Fermat spiral, the filling rate of the phased array is significantly increased Periodic modulations of PT layer with fixed periodicity leads to unidirectional discrete defect mode amplification which are also verified with COMSOL® Multiphysics [39]. vector as. the whole structure is 3D but it has 2D periodicity in x and y directions. Profile of x 3 displacement of SAW in x 1 direction when excited by a sin wave at center frequency. 3b. Send Private Message Flag post as spam. Type of periodicity. If you still need help with COMSOL and have an on-subscription I am aware that COMSOL can do the assignment of k-vectors automatically when periodic ports are used, but i would like to use scattered field formulation if possible, and in this case the k-vectors must be calculated manually AFAIK. The strain tensor components are assumed to be functions of only the in-plane coordinates x and y (and possibly time): (1) Yong’s FEM-based periodic analysis only performed DOFs eliminating located on sides of single-finger by using the anti-periodicity boundary conditions, and hence, the remaining part DOFs required to be calculated are still time-consuming. Posted 12 août 2024, 09:09 UTC−7 General, Structural Mechanics, Material Models 1 Reply . In order to extract the homogenized elasticity matrix for a composite, the Average strain periodicity type needs to be chosen. Here, we will demonstrate how to accomplish this using the General Extrusion component couplings in COMSOL Multiphysics. Posted Jun 20, 2022, 2:44 p. 32[mm] 50[mm] 15[mm]. By default, it contains the selection For User defined select the check box for any of the displacement components as needed. 2 | ANTI-REFLECTIVE COATING WITH MULTIPLE LAYERS Introduction An anti-reflective coating is a set of thin, transparent films applied to the surface of an optical device such as a lens to reduce reflection. The homogenization method introduces two scales: a macroscale and a microscale. Multiphysics Modeling of a Microfluidic Device with Periodicity 4 | CONVECTIVE HEAT TRANSFER WITH PSEUDO-PERIODICITY temperature distribution in the entire length of the pipe. In diatomic molecules, the anti-bonding eigenstate is the higher energy state as the chemical bond is weakened between the two atoms due to the destructive interference of electronic wavefunctions. 4 was very useful to calculate the homogeneized Young Modulus E. I set left-right boundary as periodic boundary condition with Floquet periodicity (the related setting as well as other boundary conditions see Structure. The cell is a microscopic domain that is representative for the material on a macroscopic length scale. Do you know how to do this ? I am working on Comsol 4. • performed DOFs eliminating located on sides of single-finger by using the anti-periodicity boundary conditions, and hence, the remaining part DOFs required to be calculated are still time-consuming. Using the model, we showed that the bonding and anti-bonding modes become degenerate at a pre-stress value that is dependent on the coupling strength. The Continuity , Antiperiodicity , and User defined periodic conditions Select a Type of periodicity: Continuity (the default), Antiperiodicity, Floquet periodicity (Bloch periodicity), Cyclic symmetry, or User Defined. If we define two spatially varying variables along this line, u_1 and u_2, and introduce a mesh along this line, then the COMSOL Multiphysics ® software can take the spatial derivative, \partial u_1 / \partial x, via the differentiation operator: d(u1,x). Several different types of periodicity properties of the solution can be prescribed using this boundary condition. Actually it is the same as Floquet condition with kF=0. The Micromechanical Model of a Fiber Composite tutorial model shows the computation of the This can be done using the RF or Wave Optics modules from the COMSOL product suite. We start by creating the geometry for a Frequency selective surfaces (FSS) are periodic structures with a bandpass or a bandstop frequency response. Each selected rotation component will be connected by or If the source and destination objects are rotated I need it to estimate the effective elastic properties of a periodic microstructure for which I know I need to use Cell Periodicity feature in Solid Mechanics. 4. Multiphysics Modeling of a Microfluidic Device with Periodicity Left: The y-component of the electric field plot, with averaged power flow arrows when the angle of incidence is 30 degrees. EDT Heat Transfer & Phase Change, Studies & Solvers Version 4. Multiphysics Modeling of a Microfluidic Device with Periodicity The Average strain periodicity type makes it possible to derive homogenized elastic properties of media with periodic structures, such as a perforated plates, porous media or composites structures. Periodic Boundary Conditions. In this case one half-period and imposing anti-periodicity conditions on the two horizontal lines. The default is 0 radians. I know it is built-in for the solid mechanics but for In the model library of Comsol there is an example of Floquet periodicity, but I haven't seen one of continuity Thanks . Right: The Periodic condition is applied to a pair of boundaries. Hello all, My name is Sai Kubair Kota and I am a PhD student at the Delft University of Technology, the Netherlands. EST Electromagnetics, Acoustics & Vibrations, Structural Mechanics Version 5. Well, I can tell about continuity that it just make your function equal on the boundaries. It also demonstrates a technique to reduce memory requirement, by solving the model repeatedly on a pseudo-periodic section of the channel. 33 Using the COMSOL Multiphysics ® software, the periodicity of such a structure can be exploited to determine the required channel length that will ensure that the chemical species leaves the system well mixed. This blog post introduces the concepts behind this type of analysis and If User defined is selected, enter values or expressions for the components of the Reinitialized particle velocity v r (SI unit: m/s). From the . 6 of the COMSOL Multiphysics® software, we have expanded the capability of the Schrödinger Equation physics interface from single-component to multiple-component wave functions. To determine the right combination of products for your modeling needs, review the Specification Chart and make Note: This discussion is about an older version of the COMSOL Multiphysics Many libraries are using Floquet periodicity for imposing periodic boundary condition. parallel to the slab’s face [1]. The cyclic symmetry boundary condition presents a special but important case of Floquet periodicity, for which the unit periodicity cell is a sector of a structure that consists of a number of identical sectors. The macroscale usually refers to the homogenized Setting up a transmission loss problem in the time domain through a periodic structure is very difficult, if the incidence is not normal to the surface. You can also add it from the Study Steps>Time Dependent submenu. Time-dependent Heat Transfer study - strange periodicity. This is Hi everyone, I'd like to use the cell periodicity boundary condition for my problem, but I have some issues understanding the equation and unfortunately, it is not specified in the User's manual: u_dst = u_src + e_avg * (r_dst - r_src) The first part is clear, but what does the second part after the plus sign stand for. In the "type of periodicity" section, I am only able to choose "continuity" or "antiperiodicity" but Floquet periodicity does not appear in the selection menu. In the frequency domain you can use the Floquet periodicity condition. In a geometrically nonlinear analysis, the Solved with COMSOL Multiphysics 5. A plane wave propagated along -z direction with x-polarization is used for the background field. What we can see from such a preliminary step is that, at least for this example, only a relatively low number of harmonics contribute most of the energy in the signal, and certain harmonics have negligible contribution. The Accumulator (Boundary) subnode is available from the context menu (right-click the parent node) or from the Physics 3 In the Settings window for Periodic Condition, locate the Periodicity Settings section. At least two boundaries must be selected. C. The COMSOL Multiphysics software is used for the results shown, but any standard finite element software that can implement Floquet periodicity (user-defined or built-in) should suffice. EST. In most cases you can also choose antiperiodicity so that the solutions have Convective Heat Transfer with Pseudo-Periodicity . The Cell Periodicity node is used to apply periodic boundary conditions to the three pairs of faces of a unit cell. In other cases, use the Destination Selection section to control the destination. I found the analytical solutions for infinite mass-spring chains with 1D-translational periodicity very helpful in understanding that the folding is more a question of how the dispersion relation is represented, but that the Set the Mode phase θ in (SI unit: rad) for the port mode field. This is the first blog post in a two-part series. I already checked the box allowing complex numbers in the solver options. The Periodic Condition node defines periodicity or antiperiodicity between two boundaries. EDT. Each selected displacement component will be connected by or respectively. Should I make a new study for Linear Buckling, or is it supposed to go inside the Cell Periodicity study I used The Periodic Condition node adds a periodic boundary condition that can be used to reduce the model size by using symmetries and periodicities in the geometry and physics interfaces being modeled. Modeling Periodic The E k diagram has now changed so that certain energies are forbidden. For an eigenfrequency study, one can show that all the eigenmodes of the full problem can be found by performing the analysis on one sector of symmetry only and imposing the cyclic symmetry of the eigenmodes with an angle of periodicity , where the cyclic symmetry mode number m can vary from 0 to N /2, with N being the total number of sectors Triangular lattice elasticity matrix calculation with cell periodicity. EDT Acoustics & Vibrations Version 5. Posted Jun 19, 2013, 4:21 a. The phase shift between transduction center and reflection centre is calculated using equation If User defined is selected, enter values or expressions for the components of the Reinitialized particle velocity v r (SI unit: m/s). The Periodic Condition node adds a periodic boundary condition that can be used to reduce the model size by using symmetries and periodicities in the geometry and physics interfaces being modeled. Periodic condition: Continuity , antiperiodicity and Floquet. In my humble opinion, effect of "Floquet periodicity option" and "Continuity option" might be same. Floquet periodicity is typically used for models involving plane waves interacting with periodic structures. Finally, we identify a number of complex waveguides for which dispersion curves can be found with relative ease by using the periodicity inherent to the Periodic condition: Continuity , antiperiodicity and Floquet. Another challenge is setting up good radiation conditions at both sides of the system. The other pair of side walls is configured to be a perfect electric conductor. This is the second blog post in a two-part series. Each selected displacement component will be connected by or . Dear amit sir, How we find the effective density by using comsol multiphysics of my periodic reentrant structure structure. The Periodic Condition node adds a periodic boundary condition that can be used to reduce the model size by using symmetries and periodicities in the geometry and physics modeled. Read Part 1 here. F. By default, it contains the source Using COMSOL Multiphysics, we can greatly reduce our computational requirements for such problems by using General Extrusion component couplings and the Previous Solution operator. This study contains a stationary study step that solves for the parent physics interface only. For Floquet–Bloch periodicity, enter the k-vector for Floquet periodicity k F (rad/m). COMSOL Code Qiaozhen Zhang 1, Zhenglin Chen 2,*, Yanguang Chen 2, formed DOFs eliminating located on sides of single-finger by using the anti-periodicity boundary conditions, and hence, the The central part of the geometry, containing the rotor and part of the air-gap, is modeled as rotating relative to the coordinate system of the stator. From the Base list, choose Center. The default is the null vector, reducing the condition to be equivalent to Continuity. Periodic boundary conditions must have compatible meshes. By providing your email address, you consent to receive emails from COMSOL AB and its affiliates about the COMSOL Blog, and agree that The frequency content of a trapezoidal pulse wave (left) and in terms of cumulative sum (right). Figure 1: Temperature distribution along the pipe, the inlet is of section 1 at the left boundary. I have been trying to calculate the homogenized elasticity matrix of a triangular lattice material with its RVE and the cell periodicity feature in coupled thin-plate elastic resonator system in COMSOL Multiphysics®. The structure is typically a unit cell of a repetitive structure. m. This is Did you know that the COMSOL Multiphysics® software allows you to have different discontinuous meshes in neighboring domains? Although the usual default behavior of the software is to use aligned meshes, there are times when we might like to have discontinuous meshes, such as for modeling conjugate heat transfer. This feature works well for cases like opposing parallel boundaries. The boundaries must be planar and cannot be curved. For User defined specify the components of the k-vector for Floquet periodicity k F (SI unit: rad/m). 3b 2 Replies . 5 In the xw text field, type 4. Based on COMSOL Multiphysics 5. Read Part 2 here. I also chose periodic boundary conditions of Floquet periodicity. For more information about these sections, see Excluded Surfaces, Excluded Edges, and Excluded Points in the COMSOL Multiphysics Reference Manual Using COMSOL Multiphysics, we can greatly reduce our computational requirements for such problems by using General Extrusion component couplings and the Previous Solution operator. Note that the sum of reflectance and transmittance in Figure 4 and Figure 5 equals 1, The Floquet periodicity can be used for frequency domain problems with a spatial periodicity of the geometry and solution. Particular functionality may be common to several products. COMSOL Moderator. 3 In the Settings window for Difference, locate the The Floquet periodicity can be used for frequency domain problems with a spatial periodicity of the geometry and solution. Posted 20 ago 2016, 03:59 GMT-4 Modeling Tools & Definitions, Parameters, Variables, & Functions 1 Reply If you still need help with COMSOL and have an on-subscription license, please visit our Support Center for help. 276 MHz, which means the unidirectional behavior of the structure. For some reason, I am way periodicity may be implemented in FDTD by setting a constant wavenumber in the periodic direction. See Constraint Settings in the COMSOL Multiphysics Reference Manual for more Excerpt from the Proceedings of the COMSOL Conference 2008 Boston. By default, it contains the selection that COMSOL Cell periodicity. Before we delve into our Finned Pipe demo app, let’s explore the physics behind the underlying model. The Destination Selection subnode is available from the context menu (right-click the parent node) see Constraint Settings in the COMSOL Multiphysics Reference Manual. In the figure the where is global average strain tensor, and u * is a function that is periodic from one unit cell to another. This can be done automatically by enabling Physics-controlled mesh in the Sequence Type section in the settings for the mesh or by manually setting up the correct mesh sequence Use the Cell Periodicity node to model a periodic unit cell or RVE (representative volume element) of a larger repetitive structure. 6 [13, 39], the guided wave dispersion curves in an aluminum beam (Young's modulus 69 GPa, Poisson's ratio 0. It is counterintuitive for the anti-bonding state to have lower energy given the bonding state has stronger chemical bond and is more stable. Physics. Expressions for the reinitialized particle velocity are evaluated at the source boundary, not the destination; for example, expressions in terms of tangential and normal vector components will use the directions tangent or normal to For Floquet-Bloch periodicity, enter the k-vector for Floquet periodicity k F (rad/m). Is it possible to make a geometry in Comsol that combines a periodically repeating structure and one non-periodic element? Like in this figure: The Periodic Condition node defines periodicity or antiperiodicity between two boundaries. 9 1 Introduction T his guide describes the Wave Optics Module, an optional add-on package for COMSOL Multiphysics ® designed to assist you to set up and solve electromagnetic wave problems at optical frequencies. In this case, you have to examine six load cases in 3D. Is it right? 3. Floquet periodicity — There is a phase shift between the fields on the two parallel boundaries. Figure 3: Magnetic field, H y (slice) and power flow (arrows) for TM incidence at 70 ° inside the unit cell. If erroneously selected, it will be reduced to the continuity condition. If the source and destination boundaries are rotated with respect to each other, a transformation is automatically performed, so that I looked into the model, the cell volume drop-down in the cell periodicity feature should be set user defined with volume = 17. Posted Jan 28, 2020, 11:10 a. For Continuity the values of the field variables Select a Type of periodicity: Continuity (the default), Antiperiodicity, Floquet periodicity (Bloch periodicity), or Cyclic symmetry. Please login with a confirmed email address before reporting spam If you still need help with COMSOL and have an on-subscription license, please visit our Support Center for help. For periodicity, PEC(PMC) condition can be used when electric The Cell Periodicity feature facilitates the evaluation of such average properties. In the figure the repeated zone scheme is shown. Since I am applying cosserate medium, I have to use the weak form PDE instead of solid mechanics. Both modules provide Floquet periodic boundary conditions and periodic ports and compute the reflected and transmitted diffraction orders as a function of incident angles and wavelength. By default it contains the selection that COMSOL To add a periodic boundary condition, in the Model Builder, right-click a physics interface node and select Periodic Condition. By default it contains the selection The combination of COMSOL ® products required to model your application depends on several factors and may include boundary conditions, material properties, physics interfaces, and part libraries. The COMSOL multiphysics software is a finite element tool for multi-physical coupling analysis in The Periodic Condition node can be used to define periodicity for the mass transport between two sets of boundaries. 4 From the Type of periodicity list, choose Floquet periodicity. Chaojun Jiang Note that while COMSOL employees may participate in the discussion forum, The Periodic Condition sets up a periodicity between the selected boundaries. For From periodic port the k-vector for Floquet periodicity k F is Have you solved the problem you encountered. Orientation of Source. See Constraint Settings in the COMSOL Multiphysics Reference Manual for more For Floquet periodicity, also known as Bloch periodicity, enter a k-vector for Floquet periodicity k F (SI unit: rad/m) for the x, y, and z coordinates (3D components), the r and z coordinates (2D axisymmetric components), or x and y coordinates (2D components). So the Floquet periodicity type is used for the The Periodic Condition node defines periodicity or antiperiodicity between two boundaries. Among them one of the condition is Floquet bloch condition. By default it contains the selection that COMSOL Multiphysics identifies. The The Periodic Condition node adds a periodic boundary condition that can be used to reduce the model size by using symmetries and periodicities in the geometry and physics interfaces being modeled. Periodic Condition 2. The rotor and the stator are created as two separate geometry objects, so it is required to use an assembly (see the Geometry chapter in the COMSOL Multiphysics Reference Manual for details). Now I'm trying to use it to study Linear Buckling and plastic collapse but I've been having some issues setting it up. FDTD Implementation Generally, an electric or magnetic field U(r;t) may be expressed as the real part of the inverse Fourier transform U s(r;t) = 1 2ˇ Z 1 1 Ue(r;!)ej!td! (10) In a material with a lattice vector d, the field U ssatisfies the. For Floquet condition I can understand from Bloch function, but the continuity and antiperiodicity, I searched but no answer. 5 and MATLAB 2020a, the calculation was implemented on two high Finned pipes usually show a geometrical periodicity along the length, which we will take advantage of in this demo app to reduce computational costs. It is based on the idea of a repeating unit cell (RUC) or a representative volume element (RVE). The beam is steered only around the y-axis. I am simulating optical transmission through sub-wavelength hole arrays by comsol 4. „Nanowire Single- photon detector with an integrated optical cavity and anti -reflection coating” Optics Express 14, 527, (2006) periodicity o Extended cavities are ~3λ/4: o Grating-coupling at 2°, 15° and 53°. Periodic or homogeneous boundary conditions are then used on the cell outer boundaries. In a geometrically nonlinear analysis, the average strains For Floquet periodicity also enter the source for the k-vector for Floquet periodicity. 3 Replies Last Post Feb 15, 2012, 7:30 a. 2 1 | FREQUENCY SELECTIVE SURFACE, COMPLEMENTARY SPLIT RING RESONATOR Frequency Selective Surface, Complementary Split Ring Resonator Periodicity Settings section. If you still need help with COMSOL and have an on-subscription license, please visit our Support Center This seems like a perfect fit for the Cell Periodicity feature, which was introduced in version 5. This can be done automatically by enabling the Physics-control mesh in the setting for The Electromagnetic Waves, Frequency Domain Interface or by manually setting up the correct 5 | FRESNEL EQUATIONS For the TM case, Figure 3 visualizes the y component of the magnetic-field distribution instead, again in combination with the power flow. For instance, if the inspected port mode field is polarized in the opposite direction compared to the expected direction, a Mode phase of π (enter pi in the field) can be used for polarizing the mode field in the expected direction. The periodic boundary conditions of the Cell Periodicity feature can also be used to find the effective coefficient of thermal expansion or coefficient of hygroscopic swelling. The default is zero. Introduction. To add a periodic boundary condition, in the Model Builder, right-click a physics interface node and select Periodic Condition. Use the Cell Periodicity node to model a unit cell (representative volume element; RVE) of a larger repetitive structure. Hello Niels Hoekstra Apply floquet periodicity in PDE to plot complex band structure. 2 0 Replies . Hello, I've been working with the domain module "Cell Periodicity" on 3D structural mechanics for a while to obtain the Elastic Matrix and Compliance Matrix of different microstructures defining a RVE geometry. I noticed that I need to provide the expression of strain in each direction, but I only want to prescirbe strain in x direction. been trying to calculate the homogenized elasticity matrix of a triangular lattice material with its RVE and the cell periodicity feature in COMSOL. Materials and Solid Mechanics Material Properties in the Materials chapter in the COMSOL Multiphysics Reference Manual. It is identical to the Time Dependent study and is used to convert a periodic steady-state solution to a time-dependent solution. This allows the simulation of a wider range of systems, such as particles with spins and the valence band structure with a mixing of 8 | FREQUENCY SELECTIVE SURFACE, PERIODIC COMPLEMENTARY SPLIT RING 4 Locate the Position section. The spacing, d, is the periodicity in the plane defined by the \bf{n Yong’s FEM-based periodic analysis only performed DOFs eliminating located on sides of single-finger by using the anti-periodicity boundary conditions, and hence, the remaining part DOFs required to be calculated are still time-consuming. Specify the . There are a lot of options in periodic conditions Tab including "Type of periodicity", "Constraint Type". I am now trying to do Bloch wave analysis to an cosserate medium. Figure 3-2 can be redrawn in various ways. By default, it contains the selection The Periodic Condition can be used to remove particles that make contact with a source boundary and reinsert them at some other boundary, the destination. Hi all, I am new to Comsol and find it very convenient to use. The Destination Selection subnode is available from the context menu (right-click the parent node) see Orientation of Source and Destination in the COMSOL Multiphysics Reference Manual. The phase shift is determined by a wave vector and the distance between the source and destination. 209 MHz and ω0 2 = 98. As the water flows through the pipe it reaches a maximum temperature of 294 K. Frequency Selective Surfaces (FSS) The frequency responses of periodic structures such as FSS, RIS, The Cell Periodicity feature facilitates the evaluation of such average properties. Frank In diatomic molecules, the anti-bonding eigenstate is the higher energy state as the chemical bond is weakened between the two atoms due to the destructive interference of electronic wavefunctions. The ground state switches from the bonding to the anti-bonding mode and vice-versa around the mode The Shell-and-Tube Heat Exchanger tutorial model geometry (left). 3 Anti-Reflective Coating with Multiple Layers. For circular periodicity, a rotation matrix, not a linear shift, must be used in the destination map. e. If required, activate periodic conditions on more than two boundaries, in which case the Periodic Condition tries to identify two separate surfaces that can each consist of several connected boundaries. Rajeev Kumar . Notice that a change of the Mode phase, either on the exciting With the help of Floquet periodicity boundary conditions in COMSOL Multiphysics 5. If the source and destination boundaries are rotated with respect to each other, a transformation is automatically performed, so that Plotting with Floquet periodicity. Recently I've been told to research the mechanical proberties of trabecular bone tissue, since it's a random structure I have to define But the physics is not just a sign issue, there are a bit more, as the flux direction is either "symmetric" or "anti-symmetric" hence for each physics you might have a different sign combination, and when you have many physics one must consider each one carefully, Not sure COMSOL can tell without having the user to define this, as I did in the Scattered field formulation: User defined k vectors for floquet periodicity. Homogenization method. Activate the Equation Learn how to use the Periodic boundary condition to numerically simplify your RF models in COMSOL Multiphysics® (includes 4 examples). In addition, we want to keep the simulated geometry close to square, in order to have well- The Periodic Condition node defines periodicity or antiperiodicity between two boundaries. Use the COMSOL Desktop to set-up the heat transfer 8 | FREQUENCY SELECTIVE SURFACE, PERIODIC COMPLEMENTARY SPLIT RING 4 Locate the Position section. This scheme highlights the periodicity of the lattice and makes clear the concept of energy bands and band Created in COMSOL Multiphysics 5. Please login with a confirmed email address before reporting The diffraction points are plotted in the plane of periodicity, and the highlighted points that lie within the reflection and transmission hemispheres indicate which diffraction orders will be present. Then for each selection, choose the Type of periodicity — Continuity or Antiperiodicity. PST RF & Microwave Engineering, Parameters, Variables, & Functions, If you still need help with COMSOL and have an on-subscription license, please visit our Support Center for help. This scheme highlights the periodicity of the lattice and makes clear the concept of energy bands and band This can be done using the RF or Wave Optics modules from the COMSOL product suite. 3a, Version 4. The spacing, d, is the periodicity in the plane defined by the \bf{n When selecting Floquet periodicity, the k-vector must be choosen from either the periodic port or user defined values. This example simulates convective heat transfer in a channel filled with water. In transient mode, there are only 2 types of periodicity: continuity and antiperiodicity. For time dependent studies, the Floquet–Bloch periodicity option does not apply. The unit cell needs to be analyzed for six different load cases. The COMSOL multiphysics software is a finite element tool for multi-physical coupling analysis in Note: This discussion is about an older version of the COMSOL Multiphysics Flouquet periodicity on Eigenfrequency analysis 3D. The frequency response problem can then be solved in one sector of periodicity by applying the periodicity condition. 1. 4 brings several new features and tutorial models to the Structural Mechanics Module. Posted Aug 16, 2013, 8:38 p. Homogenized Thermal or Hygroscopic Expansion Properties. By default, it contains the selection The Periodic Condition node can be used to define periodicity for the mass transport between two sets of boundaries. Karl K. Would I just start modelling in the 3D geometry section with the right shapes? 0 If you still need help with COMSOL and have an on-subscription license, please visit our Support The Time Periodic to Time Dependent () study is available for the Plasma, Time Periodic interface. MHz and two anti-resonant frequency at ω0 1 = 98. Due to the convenience and visualization of commercial FEM software COMSOL, the built-in quasi-3D FEM model based on COMSOL has drawn great atten- The Periodic Condition node adds a periodic boundary condition that can be used to reduce the model size by using symmetries and periodicities in the geometry and physics interfaces being modeled. 5. Some errors appear. For information about the Orientation of Source section, The Periodic Condition node adds a periodic boundary condition that can be used to reduce the model size by using symmetries and periodicities in the geometry and physics interfaces being modeled. The periodic BC used in this case is Floquet Periodicity where the displacement of the left side or source and destination The Floquet periodicity can be used for frequency domain problems with a spatial periodicity of the geometry and solution. Expressions for the reinitialized particle velocity are evaluated at the source boundary, not the COMSOL Multiphysics® version 5. This reduction of reflected light leads to A new study, named Cell Periodicity Study htcp1, with ht and cp1 referring respectively to the tags of the parent physics interface and the corresponding Cell Periodicity feature, will be created. In other cases, use a Destination Selection subnode to control the destination. In most cases you can also choose antiperiodicity so that the solutions have The Floquet periodicity correlates the source and destination boundaries with a user-specified phase in terms of k-vector. This is The Periodic Condition node can be used to define periodicity for the mass transport between two sets of boundaries. However I would like to add Floquet periodicity as periodic condition in the physics but I can't find how to achieve this. I modify the equations using weak forms, and make it floquet. The periodic boundary condition typically implements standard periodicity so that u (x 0) = u (x 1) (that is, the value of the solution is the same on the periodic boundaries). Please login with a For User defined select the check box for any of the displacement components as needed. The allowed states exist within bands of permitted energies, with band gaps separating them. excite it with a complex valued source and want to use floquet periodicity. Regards, Note that while COMSOL employees may participate in the discussion forum, COMSOL ® software users who are on Note that while COMSOL employees may participate in the discussion forum, I use complex numbers, i. For User defined select the check box for any of the displacement components as needed. If the source and destination boundaries are rotated with respect to each other, a transformation is automatically performed, This can be done using the RF or Wave Optics modules from the COMSOL product suite. Modeling a Finned Pipe in COMSOL Multiphysics. This is automatically done through the Cell Periodicity Yong’s FEM-based periodic analysis only performed DOFs eliminating located on sides of single-finger by using the anti-periodicity boundary conditions, and hence, the remaining part DOFs required to be calculated are still time-consuming. The design and physics are symmetric along the XZ-plane, enabling us to simplify the geometry by removing half (right). 5 Specify the k F vector as Add a wave equation feature, representing the GaAs pillar. Floquet periodicity. Regards, Henrik-----Henrik Sönnerlind COMSOL COMSOL Daniel Barna. To take advantage of symmetry planes and symmetry lines, all of the geometry, material properties, and boundary conditions must be symmetric, and any loads or sources must be symmetric or Floquet periodicity is typically used for models involving plane waves interacting with periodic structures. In most cases you can also choose antiperiodicity so that the solutions have Using the COMSOL Multiphysics ® software, the periodicity of such a structure can be exploited to determine the required channel length that will ensure that the chemical species leaves the system well mixed. Enter values or expressions for the components of the Average strain tensor ε avg. Periodic boundary conditions will be used on the outer boundaries of this unit cell. Since I do not have any port, I have to put it manually. For information about the Orientation of Source section, The Cell Periodicity module introduced in Comsol 5. because only that component of the k-vector is importnant for Floquet periodicity, which is perpendicular to The cyclic symmetry boundary condition presents a special but important case of Floquet periodicity, for which the unit periodicity cell is a sector of a structure that consists of a number of identical sectors. If required, activate periodic conditions on more than two boundaries, in which case the Periodic Condition tries to identify two separate surfaces that can The Cell Periodicity node offers two distinct sets of boundary conditions, namely Uniform temperature gradient and Periodic temperature, designed to suit these subvolumes respectively. By default, it contains the source For User defined select the check box for any of the displacement or rotation components as needed. 3 In the Settings window for Difference, locate the The Periodic Condition sets up a periodicity between the selected boundaries. 4. 2 The E k diagram has now changed so that certain energies are forbidden. Posted Jun 30, 2016, 6:51 a. Posted 20 août 2016, 03:59 UTC−4 Modeling Tools & Definitions, Parameters, Variables, & Functions 1 Reply Using the COMSOL Multiphysics ® software, the periodicity of such a structure can be exploited to determine the required channel length that will ensure that the chemical species leaves the system well mixed. list, choose . The k-vector for Floquet periodicity is extracted using the direction of the main beam steered by the arithmetic phase progression. The modeled structure is typically a unit cell of a repetitive structure. This example shows that only signals around the center frequency can pass through the periodic complementary split ring resonator layer. 2a 1 Reply . In the COMSOL Multiphysics® software, this generalization can be implemented using a 2D geometry of the cross section and the Solid Mechanics interface, in which the plane strain formulation is a default option. The node prescribes continuity in the concentration and the mass flux between the “source” and the “destination” side, respectively. Breggen et al. Wave Equation, Electric 2 1 In the Physics toolbar, click Domains and choose Wave Equation, Electric. See Time Dependent for information about the settings for the Time Periodic to Time For Floquet periodicity, also known as Bloch periodicity, enter a k-vector for Floquet periodicity k F (SI unit: rad/m) for the x, y, and z coordinates (3D components), the r and z coordinates (2D axisymmetric components), or x and y coordinates (2D components). † The Cell Periodicity node has three action buttons in the toolbar of the section called The Periodic Condition sets up a periodicity between the selected boundaries. You will find connections, inside that there is periodicity option. Figure 5. EDT RF & Microwave Engineering Version 4. 3 2 Replies . The new Cell Periodicity feature automates the setup of boundary conditions and loads for such a cell, and you can compute anisotropic elasticity data and coefficients of thermal expansion for use in a Note that while COMSOL employees may participate in the discussion forum, COMSOL ® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team. On the . Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH) Send Private Message Flag post as spam For Floquet periodicity, also known as Bloch periodicity, enter a k-vector for Floquet periodicity k F (SI unit: rad/m) for the x, y, and z coordinates (3D components), the r and z coordinates (2D axisymmetric components), or x and y coordinates (2D components). EDT 0 Replies . See what's new. JPG); Here giving an example, when alpha is set as 80 degree, then the I am trying to simulate a 2D periodic electromagnetic structure using periodic boundary condition in comsol multiphysics. Dear COMSOL users, I'm modelling a (reasonably simple) geometry in which I have a pulsed heat source with a period of 3 minutes (1 minute the source is on and 2 it is off). k. • What is the expected deformation of unit cell for each direction periodic condition? If you want to apply your own constraints then do the following steps 1. But since we are thinking of the spatial dimension as the time dimension, this is † In order to perform a micromechanical analysis, the Cell Periodicity node in the Solid Mechanics interface is used. The boundaries in a Boundary Pair subnode must always appear in parallel pairs. For time dependent studies, the Floquet-Bloch periodicity option does not apply. COMSOL Conference, Boston, 2015. One of them is labeled as source and the other as destination. Ruth Rubio . kx Using COMSOL Multiphysics, we can greatly reduce our computational requirements for such problems by using General Extrusion component couplings and the Previous Solution operator. Modeling Periodic Hi, I am using the Cell periodicity model in Solid mechanics module, and selected Average strain periodicity. Numerically computed effective Young's and shear moduli. ncpji thmh edem dtqy lqkb zzurc oisfyo vanks sfhijg atclfe