Method 2: Using Interpolation Functions. 6:34. Thanks. The different geological surfaces are first exported as xyz ASCII files from GOCAD® and imported in COMSOL Multiphysics® with interpolation functions. How can I solve the problem? I have defined an interpolation function T(t) for a temperature profile. ... (in comsol 4.2a). Radial Basis Function Interpolation. COMSOL Multiphysics provides a variety of built-in functions in the software. The function … produced by the meshgrid function. The COMSOL discussion forum covers a wide variety of simulation topics. Version 4.2a Heat Transfer & Phase Change Materials Raáb Donát posted 9 years ago. I'm a beginner in COMSOL 4.2a and I'm trying to simulate a model using the Microwave Heating interface. Surface Interpolation with Radial Basis Functions in COMSOL Multiphysics. You can access all manuals through File > Help > Documentation. Report. Just click the "plot" button to plot it 4. now you can use the function int1(P,T) to define material properties. This mountain of the Alps, which borders Switzerland and Italy, has a summit of 4478 meters (or 14,692 feet). I do not have an explicit function for conductivity as a function of temperature and electric field, but rather a set points of experimental data for a range of electric field and temperature values. In this way, two interpolation functions are cre-ated, one for each of the variables. I am new to COMSOL. Interpolation Functions can be used to describe material properties that are defined by a table or file containing values of the function at discrete points. We start with a model containing a … In COMSOL Multiphysics, you can use Interpolation, Analytic, and Piecewise Functions to specify a material property. 2. define interpolation function (say int1), use data from the file 3. make sure you defined the int. Our simulation in Comsol simulates temperature and mass percentage values, we would like to have the pressure value by interpolation (actually a double interpolation). If the COMSOL mesh lies outside of the space defined by the external data, then a constant extrapolation is used. Interpolation functions are documented in the Reference Manual for COMSOL Multiphysics version 5.2a, see page 277 and following. Either enter the data manually or import it from a data file. Using the Interpolation Function to Pass Boundary Conditions. I came up with a similar problem related to this topic. When COMSOL Multiphysics evaluates the function, the software performs a structured interpolation from the data values on the grid to the coordinates where the function is evaluated. I am trying to interpolate spatial-varying material data. Either enter the data manually or import it from a data file. In COMSOL Multiphysics, you can use Interpolation, Analytic, and Piecewise Functions to specify a material property. Interpolation Functions can be used to describe material properties that are defined by a table or file containing values of the function at discrete points. Either enter the data manually or import it from a data file. Browse the threads and share your ideas with the COMSOL community. Just make sure to fix the units for P and T so the text field appears in black, not in red or yellow color. I wanted to do the fatigue study by using temperature cycle as defined by IEC 61215 standard. But what do we do if the identified regions form highly irregular shapes that are not suitable for generating geom… Using interpolated function to model space dependent material property. A linear interpolation method means that the spreadsheet data is mapped linearly from the source mesh points in the data file onto the destination mesh in COMSOL Multiphysics. Thanks. 2011 à 13:09 UTC−7 Computational Fluid Dynamics (CFD), Microfluidics, Modeling Tools, Parameters, Variables, & Functions Version 4.2 1 Reply Version 4.2a Heat Transfer & Phase Change Materials Hans Parmentier posted 10 years ago. Here "argument" is the independent variable of your interpolation function; something like a position coordinate input X. Interpolation Function Help. Interpolation is usually made in one dimension, that is, the material property is considered a function of one variable. The easiest way to use interpolation of measured data is to create an interpolation function (lookup table) directly. See “Using Functions Based on Interpolated Data” on page 155 for details. 6:34. Hello, I have defined an interpolation function T (t) for a temperature profile. Interpolation functions are documented in the Reference Manual for COMSOL Multiphysics version 5.2a, see page 277 and following. A tradeoff must be found for the resolution, as too few points would result in a loss of information and too many points would create excessively large files. As an example, lets say you're using the Heat Transfer in Solids package and you want to input heat flux as a function of position X. 2020 г., 05:36 GMT-8 General, Materials, Parameters, Variables, & Functions Version 5.4 1 Reply Can you give me some suggestion? ... interpolation function problem read 1 Replies 2113 Views. A DEM file contains elevation data for a portion of the Earth’s surface. Let’s now look at how to compute these weights and visualize the interpolation function using the core capabilities of COMSOL Multiphysics. Does anybody know how Comsol selects the points where the data for the plots is evaluated (e.g. (2) Which coordinate is choosen by COMSOL to be the argument for the interpolation function? This demonstration app will fit a surface through a set of points using radial basis functions and will write out a COMSOL-format file of a smooth NURBS surface that passes through all of the points. Posted 17 февр. I have added two images to illustrate the problem. I need to define an volumetric force input F( t, r, z )as below, which varies both with time and space: You'd … In COMSOL Multiphysics, you can use Interpolation, Analytic, and Piecewise Functions to specify a material property. I use a linear interpolation function, from a txt file, to define a heat source P(x) in a equation. I'm trying to load data from a tab-delimited text file. 6:34. Hi, I have a persumeably very simple problem when using interpolation functions. Interpolation functions support up to 3 arguments, but not 4. Posted 22 mar 2011, 15:56 GMT-7 Version 5.2a 14 Replies . 2011 à 06:33 UTC−7 Modeling Tools, Parameters, Variables, ... Good Morning, I'm having trouble using COMSOL's interpolation function, and I was hoping someone might be able to help. You can access all manuals through File > Help > Documentation. Posted 19 juli 2011 13:09 GMT−7 Computational Fluid Dynamics (CFD), Microfluidics, Modeling Tools, Parameters, Variables, & Functions Version 4.2 1 Reply The COMSOL binary and text file types, with the extension .mphbin and .mphtxt, respectively, contain either geometry objects or mesh objects that can be imported directly to the Geometry or Mesh nodes in the model tree. In the previous blog post, we discussed how to loft a geometry from imported curve datausing the human head as the example of an irregular shape. Or should I use Variables? For example, on a time t1 and on a point (x1,y1), we have (T,XM) (1)= (14°C, 3.5%) : the interpolation must be done between the values [10°C : 50°C] and then between [3% : 4%]. The function describing the surface can also be written to a text file. The resulting function behaves essentially like a grid-based interpolation function. When I run the model in Comsol there is no problem, and Comsol automatically sets the derivative to zero, I see that when i plot d(P(x),x). Problem with interpolation function and variable Posted 9 июл. Interpolation Functions can be used to describe material properties that are defined by a table or file containing values of the function at discrete points. Today, let’s discuss the Matterhorn, a European mountain, as an example of an irregular shape. Best, Jeff Now I want to define a function for a heatsource: Q = const * (T(t) - T_0) If I try to modulate that function as an analytic function, COMSOL doesn´t recognice T(t). What happened to the peaks in my data?. I would like to use a interpolation function as a boundary condition. I have constructed the cycle by using interpolation, and called the function as 'therm' with units of argument in 'min' and function in 'deg-C'. Either enter the data manually or import it from a data file. My work is basically on accelerated testing of PV modules. COMSOL Multiphysics provides the solution at that time using interpolation. Interpolation Functions can be used to describe material properties that are defined by a table or file containing values of the function at discrete points. Browse the threads and share your ideas with the COMSOL community. The COMSOL discussion forum covers a wide variety of simulation topics. 6:34. Version 4.2a Heat Transfer & Phase Change Materials Raáb Donát posted 9 years ago. You can then import it without having to modify the data file but specifying, in the settings window for Interpolation, that there are 2 arguments, and, under Functions, that the position in the file for the function values is 2. † A new Elevation (DEM) function for importing elevation data in the DEM format, which was created by the US Geological Survey. Radial Basis Function Interpolation. a mesh element is slightly rotated and cut by the cut line, which node is then taken into account) and how works the interpolation (only nodes along the cut line or neighbouring nodes from above/beneath the cut line)? An Interpolation function is defined by a table or file containing the values of the function in discrete points. Now I want to define a function for a heatsource: Q = const * (T (t) - T_0) If I try to modulate that function as an analytic function, COMSOL doesn´t recognice T (t). My question is: 6:34. Posted 19 juil. Alessandro In the plot COMSOL displays x . License… Here "argument" is the independent variable of your interpolation function; something like a position coordinate input X. ... interpolation function problem read 1 Replies 2115 Views. Hi, I have a persumeably very simple problem when using interpolation functions. The COMSOL discussion forum covers a wide variety of simulation topics. When I run the model in Comsol there is no problem, and Comsol automatically sets the derivative to zero, I see that when i plot d(P(x),x). Meanwhile, in COMSOL software, the time-dependent solver provides three different time-stepping methods: the implicit BDF (backward differentiation formula) … For now, I just create an interpolation function, named "func1", which has only one argument (temperature) Either enter the data manually or import it from a data file. See the model “Rock Fracture Flow” in the COMSOL Multiphysics Model Library for an example using data interpolation. Best, Jeff How can I solve the problem? The function describing the surface can also be written to a text file. The COMSOL discussion forum covers a wide variety of simulation topics. I use a linear interpolation function, from a txt file, to define a heat source P(x) in a equation. Either enter the data manually or import it from a data file. This demonstration app will fit a surface through a set of points using radial basis functions and will write out a COMSOL-format file of a smooth NURBS surface that passes through all of the points. Comsol doesn't accept if I … But after that i don't know what are the steps that i have to followi.e what are the inputs given in global reduce model inputs and at finally obtained the response PSD in the desired direction and location. You'd … By visualizing the data, we can identify several regions with distinct properties; for example, the pores and the solid regions in a block of porous material. In COMSOL Multiphysics, you can use Interpolation, Analytic, and Piecewise Functions to specify a material property. How can I solve the problem? The COMSOL discussion forum covers a wide variety of simulation topics. Interpolation function in Geometry. Comsol doesn't accept if I … Posted 5 giu 2018, 06:07 GMT-4 Wave Optics, Materials, Parameters, Variables, & Functions Version 5.3a 0 Replies The interpolation data can be structured (defined on a … I defined a simple saw tooth interpolation function and now I want to use this function (and its derivative) in the definition of a volume force. But the surface I get (using linear interpolation function) varies from 0 -40. This demonstration app will fit a surface through a set of points using radial basis functions and will write out a COMSOL-format file of a smooth NURBS surface that passes through all of the points. This can be used to define a function z f (x, y). Radial Basis Function Interpolation Application ID: 34491 This demonstration app will fit a surface through a set of points using radial basis functions and will write out a COMSOL-format file of a smooth NURBS surface that passes through all of the points. I do not have an explicit function for conductivity as a function of temperature and electric field, but rather a set points of experimental data for a range of electric field and temperature values. Also, for random vibration part, i have given the input PSD in the interpolation function part of the global definition. Say that, by some measurement technique, we have been able to obtain data that describes how a material property varies inside a representative volume of a material. About the COMSOL Product Suite. Report. I'm new with COMSOL, and I've some doubts. I have a pretty simple model, a sphere. I am a COMSOL newbie and need some help on defining time dependent interpolation function. Browse the threads and share your ideas with the COMSOL community. In order to use these intial values in the system of PDEs, enter the name of the appropriate interpolation function as the initial value for the dependent variable in Initial Values 1. 2013 г., 02:36 GMT-7 Heat Transfer & Phase Change, Materials Version 4.2a 2 Replies Nicolas M