I have a 1D model (time dependent) and a 2D model (stationary). Sample data defined on the xy-plane, centered at the origin. Your internet explorer is in compatibility mode and may not be displaying the website correctly. This time in the x direction and using the second general extrusion operator in the u0 field. Alle Rechte vorbehalten. Then the naming and differentiation between time and spatial variables is basically a convention issue, the math behind does not really change It is really a helpful example. 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. The video shown below uses the latter of the two strategies to model a 26-meter excavation. In the COMSOL multiphysics user guide you can find a better explanation of how to use the general projection operator. General Extrusion Variable. General Extrusions is engaged in fabrication, anodizing, and powder coating, as well as aluminum finishing and machining. Settings used to revolve data about the azimuthal axis of a cylindrical coordinate system. When building the mapping, it is important to ask the following question: Given the coordinates of the destination point, how do we go to the source point? The ramp location is set to be -U_max. As the excavation reaches their depths, the struts are activated as long as the horizontal wall deflection is greater than what we allow it to be. The General Extrusion feature is available in the model tree under Component > Definitions > Component Coupling. For . Now we can add the boundary constraints, including a symmetry on the left, a fixed constraint for the bottom boundary, and a roller for the right boundaries. Similar to the first two, for the third strut, add the third strut boundary and change stage 2 to stage 3. The time varying coordinates of the point at which we want to evaluate the temperature can be entered as the coordinates of the destination map. The General Extrusion operator maps expressions defined on a source to an expression that can be evaluated on any destination geometry where the destination map expressions are valid. The General Extrusion operator will map data from the boundary into the volume, along the z direction, as shown in the following screenshots. But finally COMSOL basics is a PDE solver tool for a given subset of useful functions, of the type used for common physics (that fits in the global or coefficient form. You can fix this by pressing 'F12' on your keyboard, Selecting 'Document Mode' and choosing 'standards' (or the latest version Disp is defined as one of three different scalars (0,1.5,3 mm) as per the fourth figure. Instead, at every destination point, it first evaluates T_d(x_d,y_d) and carries out a mesh search operation to find the point on the source where this evaluation matches T_s(x_s,y_s). Your internet explorer is in compatibility mode and may not be displaying the website correctly. For example, if you would rather follow the point on the geometry that corresponds to the focal point of the moving laser, you would enter the time-varying coordinates of the focal point of the laser. However, if we neglect the structure near the inlet and the outlet, we can reasonably assume that the flow within the channel bends will be identical between the unit cells. General extrusion is one way to couple. This button displays the currently selected search type. Temperature evaluated at a point on the rotating wafer. This graph shows the wall deflection or horizontal displacement as a function of depth for different excavation steps. We were the first North American aluminum extruder to achieve ISO 9002 Certification. The boundary condition at the top side is illustrated below. In the course of building multiphysics models, we often encounter situations in which the solution to one physics is periodic or very nearly so while the solutions to other physics of interest are nonperiodic. The model in question is called Laser Heating of a Silicon Wafer, and can be found in the Model Gallery. And when you check the legends box, the plot will automatically be generated. Now we will use the operators in the physics nodes to implement the boundary conditions. For meshing the model, sometimes an automatic mesh is sufficient, but we want to make our own for this model to improve convergence on the soil-wall boundary. The temperature will vary linearly with x. point 2 there simply involves time varying coordinates of the focal point of the laser beam in the example model : http://www.comsol.com/model/laser-heating-of-a-silicon-wafer-13835. Here, the p-n junction in a diode is represented by a thin gap in the geometry. This time in the x direction and using the second general extrusion operator in the u0 field. A 2D parabolic curve given by \frac{y}{d} =(\frac{ x}{d})^2 is in a square domain of side d. Our task is to build an operator that maps data from this curve (represented in blue in the figure below) to different parts of the square. Example 1 In our earlier blog post on Linear Extrusion operators, we considered an affine mapping that pairs up points 1, 4, and 2 in the source domain to points 1, 5, and 3 in the destination domain. Select the faces that you want to extrude in the Graphics window. You can fix this by pressing 'F12' on your keyboard, Selecting 'Document Mode' and choosing 'standards' (or the latest version The other option is to start with the already excavated geometry, and simulate the excavation using a boundary load. Using a General Extrusion operator to copy data from the 2D axisymmetric domain to the corresponding 3D domain. It can be used for a variety of different purposes, examples of which are presented here. With a voltage terminal at the bottom of the device and ground at the top of the device, the following results are obtained. Within the original domain, a displacement of zero is used. You can fix this by pressing 'F12' on your keyboard, Selecting 'Document Mode' and choosing 'standards' (or the latest version Thank you! Multiscale Modeling in High-Frequency Electromagnetics. Rename this one Strut_2. General Extrusions makes no exclusions with its extrusions. Note that the operator name is kept to its default: genext1. The General Extrusion operator is used to define the velocity field in all three periodic domains. In these first two examples, the Use source map check box in the Source section of the settings window has been left unchecked. The electric potential on one side of the gap is accessed from the other side by using an extrusion operator in order to compute the current density flowing across the gap. Both cases involve mapping between points that share the same x-coordinate. The General Extrusion operator maps expressions defined on a source to an expression that can be evaluated on any destination geometry where the destination map expressions are valid. When it comes to general nonlinear mappings, General Extrusion operators are necessary. For example, to map data from a boundary around a centerline, introduce a cylindrical system, and use those coordinate system variables to define the source and destination map. Online Support Center: https://www.comsol.com/support The Linear Extrusion operator defines a linear extrusion that maps between geometric parts of the same dimension. Thus, the second line y^iexpression is left blank. Considering a variable defined on the xy-plane within a unit square centered at the origin, as shown above, it is possible to implement a variety of transforms simply via different destination maps, and leaving the source map unchanged. The source domain(s) can be the domain(s) on which the destination point(s) are defined. This problem can be solved by using a General Extrusion coupling operator to dynamically map the solution at a particular point (moving or stationary) onto a fixed source. Adding a General Extrusion coupling operator.The green vector field is the transport term used to model the wafer rotation. One application of a General Extrusioncoupling is to mirror the solution on the x-axis. You can fix this by pressing 'F12' on your keyboard, Selecting 'Document Mode' and choosing 'standards' (or the latest version Name: genext1 listed if standards is not an option). Submit feedback about this page or contact support here. Both source and destination are two-dimensional, as well as the intermediate mesh (srcdim = idim = dstdim). Hi, Your internet explorer is in compatibility mode and may not be displaying the website correctly. The General Extrusion operator will map data from the boundary into the volume, along the z direction, as shown in the following screenshots. Lets begin by looking at a microfluidic device, as shown below. Thanks for replying. At a point P_d in the destination entity, we want to compute a quantity that is a function of another quantity defined at the source entity. Although it is not strictly necessary to do so, the mesh is copied from the one domain used to solve for the fluid flow to all of the other domains. The top and bottom surfaces are thermally insulated, and there are no heat sources. Alle Rechte vorbehalten. I hope I have not missed it. You can fix this by pressing 'F12' on your keyboard, Selecting 'Document Mode' and choosing 'standards' (or the latest version Because the source entities are different, two operators are needed. Now that the velocity field is defined throughout the modeling domain, the species concentration at the inlet is defined via the Inflow boundary condition. at an interface. Similarly, on side 2, we need access to the electric potential V_1 on the other side of the junction. Extrusion operators are used to identify which point in the source entity corresponds to a point in the destination entity. Good luck Now that we have the solution on one unit cell, we can use the General Extrusion component coupling to map the solution from this one unit cell onto the repeated domains. I didn't mean to do integration, what i meant is something like: General Extrusions, Inc. produces aluminum extrusions in compliance with RoHS (Restriction of Hazardous Substances) requirements. Now that we know how to find the corresponding coordinates of the source point, given any point (x,y) in the destination, we enter the right-hand side of the above equation (without the subscripts) in the destination map of the General Extrusion settings window. I have an equation involving u(x,y), but instead of using a stationary solver I reformulate the equation as something like u(x,t), where the variable y plays a similar role as t, and hence solvable using the time dependent solver in 1D model. Data transfer between components is performed using the COMSOL built-in "General Extrusion" coupling operator, and the iterative study steps are controlled using "For" and "End For" nodes in COMSOL. Adding a General Extrusion coupling operator.The green vector field is the transport term used to model the wafer rotation. Now, add a free triangular for the remaining geometry. To apply what we have learned thus far, lets now build a diode model using the Electric Currents physics interface in COMSOL Multiphysics. Mapping of data between different components in the model to perform submodeling, Mapping between components to extract results on different geometries. Settings used to map data from a boundary parallel to the xy-plane along the z direction. General Extrusions, Inc. continues its tradition as a leading manufacturer of aluminum extrusions where quality always comes first. In fact, a shortcut can be made by using the expression genext2(V)-genext1(V) for the voltage difference, regardless of which side it is being applied. For the 2D model, I have computed the expression u(x,y). The Micromixer tutorial, available in our Application Gallery, is an example of such a model. Mapping of data between different components in the model to perform submodeling, Mapping between components to extract results on different geometries. For the y-axis data, the expression is y, and for the x axis, the expression is u, with millimeters as units. Extrusion Model Coupling Operator takes a local concentration as an argument at the following boundary and evaluates it at the corresponding point at the leading boundary. To do so, you can use General Extrusion operators to map the fields from the stator to the slider. I will always remember a Geotechnical Engineering class I took during the pursuit of my Civil Engineering degree. The schematic below illustrates that there are two fluid inlets, both of which carry the same solvent (water) but a different solute. Enter in the equation shown which is the ramp function of the wall deflection, with an added term limiting the expression to occur only when the depth is below the strut. The general extrusion operation applies a rotational transform. listed if standards is not an option). Ce consentement peut tre retir tout moment. The approach we have applied here is appropriate for any instance in which a spatially repeating solution needs to be utilized by other physics. You can learn more about the use of projection operators in this previous blog post. Hi The company's manufacturing operations, which include a Youngstown, Ohio plant, comprise 220,000 square feet. At the outlet, we want the species to be well mixed. Since there is no displacement in the y-direction, the y-expression is set at its default y. This can be useful for analysis; for example, to probe the solution at a point that is moving in time but is associated with a stationary geometry. We were the 1st North American Aluminum Extruder to achieve ISO 9002 Certification. Settings for the General Extrusion operator defined on the stator boundary. Note that V refers to the electric potential at a point on the top side while genext2(V) refers to the electric potential vertically on the bottom side. The settings for the General Extrusion operator and the definitions of the variable in the three domains. I would appreciate any help. The rest of the boundary loads will describe the three struts. We want an operator that will copy from a point on the parabola to a point in the square, such that the distance of the destination point from the origin is equal to the length of the segment of the parabola between the origin and the source point. For such a unit cell model, the walls of the channels are set to the Wall, No Slip condition. Two boundary selections have been created and renamed wall_diaphragm and wall_soil. I have the other model, where i would need this variable u, but this time, it is a 2D model, non time dependent. Posted 15 feb 2011, 16:18 UTC I have defined a general extrusion coupling operator to obtain the dependent variable (in my heat transfer case, the temperature "T") at a boundary. We have discussed how the General Extrusion component coupling can be used to set up a linear pattern of a periodic solution as part of a multiphysics analysis. The Graphics Window: Effective and Beautiful Postprocessing, Generating Microsoft PowerPoint Slideshows from Your Models, Combining Adaptive Mesh Refinement with Data Filtering. The companys manufacturing operations, which include a Youngstown, Ohio plant, comprise 220,000 square feet. We need to provide T_d and T_s, such that. Considering a variable defined on the xy-plane within a unit square centered at the origin, as shown above, it is possible to implement a variety of transforms simply via different destination maps, and leaving the source map unchanged. If the nonlocal couplings you want to simulate are not included in the built-in features of COMSOL Multiphysics, you can use the strategies youve learned today to implement them. Add a distribution for the wall diaphragm and enter 60 for the number of elements. 3 Replies, Please login with a confirmed email address before reporting spam. This moving load is then transformed into the rotating coordinate system via the General . We are then looking at the problem of evaluating the temperature at a point that follows the rotating wafer material. Mapping of data defined on a boundary (left) along the direction normal to the plane and into a volume (right). It can be used for a variety of different purposes, examples of which are presented here. -- Ce consentement peut tre retir tout moment. I deplore the glaring oversight of COMSOL: Considering how frequently one encounters problems that include a combination of Rotationally-Symmetric and Cartesian components, that COMSOL has not seen fit to provide a specific operator for this case! It can be used for a variety of different purposes, examples of which are presented here. Extruding Data Along a Direction. The focus of this blog post is on the transformation T : x_d \rightarrow x_s.. COMSOL Multiphysics offers two coupling operators to specify this mapping: Linear Extrusion operators and General Extrusion operators. COMSOL Multiphysics will take care of T_s^{-1}(T_d(x_d,y_d)), a necessary step in identifying the source coordinates. From such source-destination pairs, one can infer the general mapping from superposition. The same transforms can be implemented in three dimensions. It is also possible to define the mapping in terms of coordinate systems. listed if standards is not an option). Any affine transformation can be expressed as the sum of a linear transformation and a translation operation. I have only one small question, if you dont mind, you could maybe write the expressions of the variable disp. To implement, define a General Extrusion operator on a boundary parallel to the xy-plane, with the z-expression blank for both the Source Map and a Destination Map. How to use the General Extrusion coupling operator to probe a solution at a moving point http://comsol.com/c/10mb Here is an interesting question: How can we easily probe the solution at a point that is moving in time, but associated with a stationary geometry?. Posted 15 feb 2011, 11:18 GMT-5 Version 4.1 3 Replies . You can fix this by pressing 'F12' on your keyboard, Selecting 'Document Mode' and choosing 'standards' (or the latest version Too simple. To implement, define a General Extrusion operator on a boundary parallel to the xy-plane, with the z-expression blank for both the Source Map and a Destination Map. Take a look at the figure below. The player button feature allows you to see all the excavation depth results in one animation. From the Extrude from list, select Faces to extrude planar faces from the 3D geometry. Today, we will discuss General Extrusion operators, which are designed to handle nonlinear mappings and the mapping of variables between geometric entities of different dimensions. With the General Extrusion operator defined, we can now use it throughout the model. It can be used for a variety of different purposes, examples of which are presented here. The materials have already been created and set up for this model. comsol.com A long prismatic beam is made of 1000 1[m] cubes and we wish to solve for the thermal field in this beam, when we apply 2 distinct temperatures only at the ends of the beam - BUT the cubes have a 0.1[m] gap between them as seen in the attached image. Right click again to duplicate it twice, since we want similar settings for the second and third struts. We can simply enter the time varying coordinates in the x, y, and z-expressions of the destination map. The General Extrusion operator will map data from the boundary into the volume, along the z direction, as shown in the following screenshots. A little calculus gives us the arc length of the parabola between the origin and the source point (x,y). This gap means that we cannot connect them via pair-based continuity conditions and we then resort to the General Extrusion coupling to connect the ~2000 disjoint boundaries however with the default settings it fails to find suitable source points across the large gaps one solution is then to go to Advancedand switch the Mesh search method to Closest point- this works, but with one notable drawback: Solution time for our 3M DOF model is now 2233s the factor of 26 in solution time relative to the model without couplings can be costly, if we are to use our model in any kind of auxiliary-/parametric sweep or optimization loop. Several cases are illustrated in the table below. Once the model has finished computing we can add some post processing to better view the results. Sample data defined on the xy-plane, centered at the origin. indeed I do not believe I really understand what you intend to do. How much easier it could have been had we only known about geomechanics simulation software. Your internet explorer is in compatibility mode and may not be displaying the website correctly. Lets consider a laser heating example where you have a moving heat source, the laser, and a moving geometry. Forming an assembly creates an identity pair between the wall soil and wall diaphragm boundaries. Mapping of data defined on a cross section (left) around an axis of symmetry and into a volume (right). x_s = ax_d + by_d + e, \qquad y_s = cx_d + dy_d + f. r_s = \sqrt{x_d^2 + y_d^2}, \qquad z_s = z_d. listed if standards is not an option). As the excavation deepens, three struts are activated using a ramp function, and boolean expressions. L=\frac{x_s}{2}\sqrt{1+4(\frac{x_s}{d})^2}+\frac{d}{4}\ln(2\frac{x_s}{d}+\sqrt{1+4(\frac{x_s}{d})^2}), we introduced you to Linear Extrusion operators, earlier blog post on Linear Extrusion operators, Using the General Extrusion Coupling Operator in COMSOL: Dynamic Probe, Using General Extrusion Operators to Model Rotation, Using General Extrusion Operators to Model Periodic Structures, Submodeling: How to Analyze Local Effects in Large Models, Postprocessing Local Data Using Component Coupling, Multiscale Modeling in High-Frequency Electromagnetics.
