Help with nonlinear solver did not converge comsol. Read more about all of the updates relating to studies and solvers below. Watch this archived webinar for the basics of modeling mixers and stirred tanks using the comsol multiphysics software as well as the chemical reaction engineering module and mixer module. How to make time step to store output variable in comsol. May 17, 2017 this can leave us staring at the monitor, ready to pounce. How to add stop conditions to solvers in comsol multiphysics. Solving time dependent models with inconsistent initial values. Would you like to see a demonstration of the comsol software in real time. To start a new discussion with a link back to this one, click here.
These release notes provide information regarding new functionality in existing products and an overview of new products. Aug 12, 2015 you can define an analytic, interpolation, or piecewise function to describe any material property in comsol multiphysics. This saves memory and computing power when you only need part of the solution for visualization and results. Browse the threads and share your ideas with the comsol community. What variable timestep algorithms do is try to dynamically pick the timestep, to make it smaller when the solution is changing rapidly. To request a demonstration, simply fill out the form on this page. The time step can be a constant, a global variable expression, or determined from the separation between a monotone list of time values. Stationary analysis just solves the first thin conductive shell with the dependent variable vel. This functionality may be useful if you run the software on a system where, for some reason, there is no user interface. How to access a variable value at a particular time in comsol. As for computational issues, one example is a very small time step size taken by the solver. Comsol multiphysics is a crossplatform finite element analysis, solver and multiphysics simulation software. In comsol multiphysics, a stop condition can be added to the following solvers.
Sep 11, 2016 in this video, two dimensional heat transfer problem is solved using comsol multiphysics software. I want to conduct a simulation to find a solution u and its first derivative ux using a 3d stationary model. Comsol multiphysics software understand, predict, and optimize. In a timedependent simulation, the time steps can get smaller and the. Fixed a problem with mphplot that prevented older versions of the matlab software to work with comsol multiphysics software version 5. It seems like on every simulink simulation step, comsol model in executed and calculated the number of simulation steps specified by the timedependent solver, while the input variables are. Forum application exchange comsol blog multiphysics cyclopedia. To accurately account for realworld effects and behavior in your geotechnical analyses, you can include multiphysics effects by combining the features and functionality in the geomechanics module with other modules in the comsol product suite. In this video, two dimensional heat transfer problem is solved using comsol multiphysics software. When running studies in comsol multiphysics version 5. Sorry i have no idea of which integration schemes are implemented in comsol, and i doubt that there is a onesizefitsall one used by default. Get methods for time step and order selection here.
How to specify material properties with functions in comsol. Time stepping in comsol multiphysics computational science. Once you have created a comsol multiphysics model of your product or process, you always want to improve on your design. Let us take a look at some time stepping schemes used by the comsol software.
To specify the initial time step size, go to the time dependent solver settings, time stepping section, enable the initial step. Pipe flow software enables you to model flow and heat transport in pipe networks. How to access a variable value at a particular time in comsol during simulation. This discussion is about an older version of the comsol multiphysics software. Some of the distinct advantages i have experienced are.
In other words, i need to know how it is possible to change, for example, the time variable from to. The comsol multiphysics time dependent transient solvers have the capability of. Comsol multiphysics is an engineering, design, and finite element analysis software environment for the modeling and simulation of any physicsbased system. If using the windows operating system, this is located in the file menu under help. The update can be applied directly to an installation of version 5. This way, we can work on something else while the software checks the conditions after each step. Plus, it is possible to replicate the functionality of other specialized software in comsol and get results that are just as accurate. Detailed explanation of the finite element method fem. Feb 02, 2012 i mostly let comsol choose the default solver when i get rather convinced i have checked all other items that could be wrong, then only i start to see if i should change the sovler. This means that the software will automatically adjust the timestep size to maintain the. Studies and solvers store selected parts of a solution. I am using a fully coupled advanced, direct solver for now, as i havent been able to get a segregated solver to converge for even the first time step. When you expand comsol multiphysics with the acdc module, you unlock features for specialized lowfrequency electromagnetics modeling in addition to the core functionality of the comsol multiphysics software platform. Comsol reduces the time step size when it does not converge in the time or spatial domain, or even i believe, if it converges in the spatial domain but requires a lot of iterations.
I actually dont mind that the timesteps take longer but the real issue is that the size of the timesteps are extremely small. In this blog post, we discuss how to automate this process in the comsol multiphysics software. Time step dependent on a variable comsol multiphysics. Please indicate what you would like to simulate so we may better assist you. Aug 14, 2018 fixed a problem with mphplot that prevented older versions of the matlab software to work with comsol multiphysics software version 5. The galerkin method one of the many possible finite element method formulations can be used for discretization. Is there a way to use the stationary solution obtained in comsol 4.
We also have the option to see what happens the first time the conditions are violated. Mathematical modelling and simulation with comsol multiphysics ii. It allows conventional physicsbased user interfaces and coupled systems of partial differential equations pdes. The acdc module includes the tools necessary for modeling. Suppose, for example, that at each time step, the model requests the time integral from start until now over the total heat flux magnitude, which measures the accumulated energy. In time dependent study one can define the range like 0,0. How to use a previous solution of a set of equations as a functionvariable in a new set of equations. In order to check that the update installation was successful, first start the comsol multiphysics software and select the about comsol multiphysics menu option.
Additional multiphysics possibilities, such as fluidstructure interaction, are available when combined with other modules within the comsol product suite. The standardized comsol desktop user interface, which is the basis for the electrodeposition module, is also used for all the other addon products in the comsol product suite. In previous versions of the comsol software, you could not start a batch sweep or cluster sweep from a batch command, but this functionality is now available with the new commandline options mode batch and mode desktop. Solution operator in a transient model in comsol multiphysics. This enables you to couple the physics describing your electrodeposition or etching process to other modules, such as the heat transfer module for studying thermal. It is very easy to learn provided one must know the underlying theory behind the simulation, i. Cfd software for simulating fluid flow applications.
You will need an onsubscription comsol license attached to your comsol access account or a software trial provided by your sales representative. In addition to using multiphysics modeling for your own projects, you can also turn your models into simulation applications and. How can i evaluate variable at point after each time step and at main. To specify the initial time step size, go to the timedependent solver settings, time stepping section, enable the initial step. This saves memory and computing power when you only need part of the solution for visualization and. With the cfd module, you can model conjugate heat transfer and reacting flows in the same software environment you use to analyze fluid flow problems simultaneously.
If not, do this time step again with updated boundary condition until criteria are satisfied. Overview of integration methods in space and time comsol blog. Watch this video series to learn how to create some of the most frequently used plot types in comsol multiphysics. How to access a variable value at a particular time in. Browse and download documentation to get started using the comsol software. Trying to increase timestep in comsol cfd cfd online. This can involve testing a bunch of different timesteps, and picking one that gives acceptable error with respect to the finest grid its checked. As of update 2, the new rotordynamics module is available as. How can i add a time dependence variable or dipolefor example in a time dependence study.
Use this new functionality with the following steps. With the help of capterra, learn about comsol multiphysics, its features, pricing information, popular comparisons to other simulation products and more. The update can be applied directly to an installation of. Comsol multiphysics alternatives and similar software. You will experience speedup by a factor of up to ten in software responsiveness, as well as new and improved features for solving, meshing, and the physicsbased addon modules. Comsol is one of the best software to date for multiphysics applications. Blog automatic time step and order selection in timedependent problems. As soon as an expression contains a variable raised to a power c omsol multiphysics version 4. Time dependent study consists of solving the second thin conductive shell tf and heat transfer t.
As of update 2, the new rotordynamics module is available as an optional addon to the structural mechanics module. Dear comsol users, does anyone know the name of the variable where comsol saves the current time step, so it could be used in an expression. Controlling the time dependent solver timesteps comsol. Optimize your models for the real world with the comsol multiphysics software for. The variable for the total heat flux is automatically calculated by comsol and is named ht. Then use this file to provide the initial conditions in time dependent model. Using the previous solution operator in transient modeling. If you do not yet have a comsol access account, please create one now.
Each video shows a stepbystep demonstration of how to create certain plot types and the advantages of using each of them. In addition to using multiphysics modeling for your own projects, you can also turn your models into simulation applications and digital twins for use by other design teams. The comsol discussion forum covers a wide variety of simulation topics. Comsol provides an ide and unified workflow for electrical, mechanical, fluid, acoustics and chemical applications. With the weak formulation, it is possible to discretize the mathematical model equations to obtain the numerical model equations. Standard accelerator simulation software can typically only simulate one species at a time. Forum set solution of previous time step as initial condition. Note that while comsol employees may participate in the discussion forum, comsol software users who are onsubscription should submit their questions via the support center for a more comprehensive response from the technical support team. But reasdd also carefully the kb, use time step as search.
Discussion closed this discussion was created more than 6 months ago and has been closed. If that was possible at all i looked through the manual and could not find anything. Trial licenses are automatically associated with your account. Using plots to visualize results in comsol multiphysics. The timedependent solver in the comsol multiphysics software offers three. You can get a sense of the cause of the small time step from the log output. You can use the new rk solvers from the standard timedependent solver node. Hi everybody, someone can tell me how to shift the time variable t in comsol 3. This requires that the values of dependent variables in the transient study are. The update includes all performance and stability improvements from 5. Working with specific soil, rock, and concrete models, this functionality is especially useful for testing how. Automatic time step and order selection in timedependent.
Includes tools to calculate pressure drop through friction and components. Comsol will, by default, attempt to reconcile inconsistent initial values by taking a. It seems like on every simulink simulation step, comsol model in executed and calculated the number of simulation steps specified by the time dependent solver, while the input variables are. How to make time step to store output variable in comsol multiphysics. These algorithms use the solutions at several previous time steps up to five to. If using the linux and macos operating systems, this is located in the help menu. Livelink for revit fixed a problem related to installing the livelink for revit product on a chineselanguage operating system 1. This is the first step in the finite element formulation. Comsol multiphysics creates sequences to record all steps that create the geometry, mesh. Complete product documentation can be found during the installation process or in the help menu when running the software. The optimization module is an addon package that you can use in conjunction with any existing comsol multiphysics product. Note that the software is still free to choose a timestep smaller than this value, but will not make it larger. Comsol multiphysics is a generalpurpose simulation software for modeling designs, devices, and processes in all fields of engineering, manufacturing, and scientific research. By default, the initial timestep is automatically determined based upon the total.
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