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. If you do not yet have a comsol access account, please create one now. What variable timestep algorithms do is try to dynamically pick the timestep, to make it smaller when the solution is changing rapidly. In time dependent study one can define the range like 0,0.
The update includes all performance and stability improvements from 5. Would you like to see a demonstration of the comsol software in real time. Fixed a problem with mphplot that prevented older versions of the matlab software to work with comsol multiphysics software version 5. It is very easy to learn provided one must know the underlying theory behind the simulation, i. Comsol will, by default, attempt to reconcile inconsistent initial values by taking a. You can use the new rk solvers from the standard timedependent solver node. Please indicate what you would like to simulate so we may better assist you. To start a new discussion with a link back to this one, click here. Using plots to visualize results in comsol multiphysics.
As soon as an expression contains a variable raised to a power c omsol multiphysics version 4. 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. The galerkin method one of the many possible finite element method formulations can be used for discretization. If that was possible at all i looked through the manual and could not find anything. 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. Solution operator in a transient model in comsol multiphysics. Pipe flow software enables you to model flow and heat transport in pipe networks. Livelink for revit fixed a problem related to installing the livelink for revit product on a chineselanguage operating system 1. 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. Hi everybody, someone can tell me how to shift the time variable t in comsol 3.
In order to check that the update installation was successful, first start the comsol multiphysics software and select the about comsol multiphysics menu option. How to access a variable value at a particular time in comsol. May 17, 2017 this can leave us staring at the monitor, ready to pounce. 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.
This is the first step in the finite element formulation. When running studies in comsol multiphysics version 5. In this video, two dimensional heat transfer problem is solved using comsol multiphysics software. Use this new functionality with the following steps. But reasdd also carefully the kb, use time step as search. Working with specific soil, rock, and concrete models, this functionality is especially useful for testing how. Optimize your models for the real world with the comsol multiphysics software for. Time stepping in comsol multiphysics computational science. How to make time step to store output variable in comsol. 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. How to access a variable value at a particular time in comsol during simulation. Standard accelerator simulation software can typically only simulate one species at a time. Get methods for time step and order selection here.
Using the previous solution operator in transient modeling. It allows conventional physicsbased user interfaces and coupled systems of partial differential equations pdes. Read more about all of the updates relating to studies and solvers below. This way, we can work on something else while the software checks the conditions after each step. The timedependent solver in the comsol multiphysics software offers three. Forum set solution of previous time step as initial condition. Comsol provides an ide and unified workflow for electrical, mechanical, fluid, acoustics and chemical applications. Aug 12, 2015 you can define an analytic, interpolation, or piecewise function to describe any material property in comsol multiphysics. Comsol multiphysics alternatives and similar software. 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. 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. Discussion closed this discussion was created more than 6 months ago and has been closed.
As of update 2, the new rotordynamics module is available as. Time step dependent on a variable comsol multiphysics. The comsol multiphysics time dependent transient solvers have the capability of. I actually dont mind that the timesteps take longer but the real issue is that the size of the timesteps are extremely small. This requires that the values of dependent variables in the transient study are. Is there a way to use the stationary solution obtained in comsol 4. The acdc module includes the tools necessary for modeling. I want to conduct a simulation to find a solution u and its first derivative ux using a 3d stationary model. Browse the threads and share your ideas with the comsol community. Mathematical modelling and simulation with comsol multiphysics ii. This saves memory and computing power when you only need part of the solution for visualization and results. Then use this file to provide the initial conditions in time dependent model.
As for computational issues, one example is a very small time step size taken by the solver. Comsol multiphysics software understand, predict, and optimize. These algorithms use the solutions at several previous time steps up to five to. In other words, i need to know how it is possible to change, for example, the time variable from to. 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.
Detailed explanation of the finite element method fem. Once you have created a comsol multiphysics model of your product or process, you always want to improve on your design. Some of the distinct advantages i have experienced are. 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. Comsol multiphysics creates sequences to record all steps that create the geometry, mesh. In comsol multiphysics, a stop condition can be added to the following solvers. Complete product documentation can be found during the installation process or in the help menu when running the software. In this blog post, we discuss how to automate this process in the comsol multiphysics software. How to access a variable value at a particular time in.
This means that the software will automatically adjust the timestep size to maintain the. 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. Includes tools to calculate pressure drop through friction and components. Trying to increase timestep in comsol cfd cfd online. 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. Cfd software for simulating fluid flow applications. How to make time step to store output variable in comsol multiphysics.
Blog automatic time step and order selection in timedependent problems. 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. Each video shows a stepbystep demonstration of how to create certain plot types and the advantages of using each of them. To request a demonstration, simply fill out the form on this page. Time dependent study consists of solving the second thin conductive shell tf and heat transfer t. How to use a previous solution of a set of equations as a functionvariable in a new set of equations. To specify the initial time step size, go to the timedependent solver settings, time stepping section, enable the initial step. As of update 2, the new rotordynamics module is available as an optional addon to the structural mechanics module. In a timedependent simulation, the time steps can get smaller and the. In addition to using multiphysics modeling for your own projects, you can also turn your models into simulation applications and. Watch this video series to learn how to create some of the most frequently used plot types in comsol multiphysics. If using the linux and macos operating systems, this is located in the help menu.
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. How can i evaluate variable at point after each time step and at main. The update can be applied directly to an installation of version 5. How to specify material properties with functions in comsol. With the weak formulation, it is possible to discretize the mathematical model equations to obtain the numerical model equations. This can involve testing a bunch of different timesteps, and picking one that gives acceptable error with respect to the finest grid its checked. The optimization module is an addon package that you can use in conjunction with any existing comsol multiphysics product. If not, do this time step again with updated boundary condition until criteria are satisfied. Plus, it is possible to replicate the functionality of other specialized software in comsol and get results that are just as accurate. This saves memory and computing power when you only need part of the solution for visualization and.
Comsol multiphysics is an engineering, design, and finite element analysis software environment for the modeling and simulation of any physicsbased system. Controlling the time dependent solver timesteps comsol. You will need an onsubscription comsol license attached to your comsol access account or a software trial provided by your sales representative. Comsol is one of the best software to date for multiphysics applications. 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. Forum application exchange comsol blog multiphysics cyclopedia. This discussion is about an older version of the comsol multiphysics software. Additional multiphysics possibilities, such as fluidstructure interaction, are available when combined with other modules within the comsol product suite. Studies and solvers store selected parts of a solution. The variable for the total heat flux is automatically calculated by comsol and is named ht. 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. You can get a sense of the cause of the small time step from the log output. Note that the software is still free to choose a timestep smaller than this value, but will not make it larger. 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 update can be applied directly to an installation of. Comsol multiphysics is a crossplatform finite element analysis, solver and multiphysics simulation software. We also have the option to see what happens the first time the conditions are violated. How to add stop conditions to solvers in comsol multiphysics. With the help of capterra, learn about comsol multiphysics, its features, pricing information, popular comparisons to other simulation products and more. If using the windows operating system, this is located in the file menu under help. Comsol multiphysics is a generalpurpose simulation software for modeling designs, devices, and processes in all fields of engineering, manufacturing, and scientific research. To specify the initial time step size, go to the time dependent solver settings, time stepping section, enable the initial step. 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. Overview of integration methods in space and time comsol blog.
The comsol discussion forum covers a wide variety of simulation topics. Trial licenses are automatically associated with your account. These release notes provide information regarding new functionality in existing products and an overview of new products. We discuss defining and solving fluid flow and chemical reaction problems with functionality such as rotating geometries, free surfaces, and a wide. By default, the initial timestep is automatically determined based upon the total. Solving time dependent models with inconsistent initial values. How can i add a time dependence variable or dipolefor example in a time dependence study. 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.
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