Periodic condition comsol You can use the rule of mixtures to find the effective density. g. Feb 15, 2012 · Hello everyone, I'm trying to solve a problem with periodic boundary conditions. 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. In other cases, right-click Periodic Condition and select Manual Destination Selection to control the destination. The Periodic Flow Condition splits its selection into a source group and a destination group. Use it to model, for example, a large perforated plate with an oblique incident wave with wave vector k (and set k F = k) by only analyzing one hole or one subset of holes that is periodic. Learn how to use COMSOL Multiphysics ® and the add-on Acoustics Module to simulate acoustic metamaterials in this archived webinar. Several different types of periodicity properties of the solution can be prescribed using this boundary condition. I have come up with a few ideas: The Periodic Condition node defines periodicity or antiperiodicity between two boundaries. 32[mm] 50[mm] 15[mm]. Jul 22, 2016 · In am simulating plane waves incident upon a stack of thin films (at oblique angle of incidence), each layer with different (real part of) refractive index, e. This feature works well for cases like opposing parallel boundaries. different k-vectors. This corresponds to a situation where the geometry is a periodic part of a larger geometry. This works fine for cases like opposing parallel boundaries. Effective density = integration(density*thickness)/V, where V = 17. The Destination Selection subnode is available from the context menu (right-click the parent node) or from the Physics toolbar, Attributes menu. 6 Highlights (36:24) Updates to the Scattering Boundary Conditions (39:05) New Models II Feb 4, 2019 · There are some diffent approaches you could use, but the quickest is probably to edit the constraint expressions for the periodic boundary condition in Equation View. The Periodic Condition node defines periodicity or antiperiodicity between two boundaries. Use periodic boundary conditions to make the solution equal on two different (but usually equally shaped) boundaries. In 3D edges can be connected with a periodic condition, and in 2D axisymmetry points. The node prescribes continuity in the concentration and the mass flux between the “source” and the “destination” side, respectively. You must provide coordinate systems using the Orientation of Source and Orientation of Destination sections. Feb 16, 2015 · We will begin with an existing example from the COMSOL Multiphysics Model Library and modify it slightly to include a periodic heat load and the Events interface. Use a Periodic Condition to prescribe that the displacements on two different sets of boundaries with the same geometrical shape are related, as in a periodic structure. Modeling Periodic Structures in COMSOL Multiphysics (33:00) Wave Optics 5. Ansys has that feature and in COMSOL, 'periodic boundary condition' has the same role to this. Fluid that leaves the domain through one of the destination boundaries enters the domain through the corresponding source boundary. Then modify the constraint and constraint force expressions in the periodicity condition to something like Dec 2, 2018 · This bring a problem when I apply periodic Condition (left edge and right edge of the geometry have the same temperature): I can't apply this periodic condition since solid and fluid domains are in two different tree node. Am This condition is used to model infinite periodic structures with nonnormal incident pressure fields or excitations. The presentation gives an introduction to the Acoustics Module and shows how to use the Floquet boundary conditions to model repeating structures to find their band gaps. . This condition is used to model infinite periodic structures with nonnormal incident pressure fields or excitations. The Periodic Condition node adds a periodic boundary condition. To add a periodic boundary condition, in the Model Builder, right-click a physics interface node and select Periodic Condition. This means that the orientation cannot be determined automatically. By default it contains the selection that COMSOL Multiphysics identifies. To add a periodic boundary condition, in the Model Builder , right-click a physics interface node and select Periodic Condition . Now the question is how i should define the k-vector to be used with a periodic FLOQUET boundary condition in COMSOL. This periodicity can be continuous (the default) or anti-periodic and can control which of the dependent variables that the Use periodic boundary conditions to make the solution equal on two different (but usually equally shaped) boundaries. For periodic conditions on shells the periodicity condition acts on edges, as opposed to solids and plates where it acts on boundaries. 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 Condition node can be used to define periodicity for the mass transport between two sets of boundaries. We will look at an example of the Laser Heating of a Silicon Wafer , where a laser is modeled as a distributed heat source moving back and forth across the surface of a spinning Use a Periodic Condition to prescribe that the displacements and rotations in two sets of entities with the same geometrical shape are related as in a periodic structure. Aug 8, 2014 · I'm wondering what periodic boundary condition means. Use this node to add periodic temperature conditions to boundary pairs. I mean, I have a geometry which has clear symmetric with respect to xy plane. The default coordinate system is This condition is used to model infinite periodic structures with nonnormal incident pressure fields or excitations. 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). I guess I really need to simulate just one of the half of the whole if I can apply symmetric condition to xy plane. Add 'C' as an extra DOF using a Global Equations node (without equation). In the Plate interface, the condition can be set up for edges (boundaries). This periodicity can be continuous (the default) so that u ( x 0 ) = u ( x 1 ) or antiperiodic so that u ( x 0 ) = − u ( x 1 ) and can control to which dependent variables the periodic condition applies. Oct 21, 2024 · To find effective density you do not need periodic boundary conditions. I'm not sure if it's because the COMSOL version in the video is different from mine, or I may choose the wrong physics. If I set periodic conditions with the type of continuity on a geometry of a cube, and then a prescribed displacement on a face, then the cube moves in space, but does not experience deformation because the displacement of 2 opposite faces is equal. nulvpdjfblkxjjrofkdfmqnlyujcifgkhrqeapzjygsorn