Adaptive time stepping comsol tutorial pdf

Controlling the time dependent solver timesteps comsol. Thus we fix the flow time in the examples described here, for example. Based on my experience on solving timedependent problems using my laptop, 1. To download the mphfiles, log in or create a comsol access account that is associated with a valid comsol license. Free and paid events offering a variety of learning opportunities. Most time dependent problems in comsol multiphysics are by default solved with an adaptive timestepping scheme. The book, introduction to comsol multiphysics, is a valuable tool for learning comsol simulation software and the new version is now available for download from our website. It is similar to the existing rungekutta 4 solver, but with a new feature that decides and adapts the size of the time step automatically. Introduction to comsol multiphysics, a book to get you. This means that the software will automatically adjust the timestep size to maintain the desired relative tolerance. Seepage modeling with seepw geoslope international. Pseudo time stepping is now available for the stationary solver when using a fully coupled or segregated solver. Comsol multiphysics with pseudo time stepping methodology and adaptive gridding technique to obtain a steady state solution by marching in time by capturing the shocks and expansions occurring in the flow field.

We use cookies to offer you a better experience, personalize content, tailor advertising, provide social media features, and better understand the use of our services. Events include the annual comsol conference, local comsol days, and inperson workshops. Will the increase of the relative tolerance reduce the solving time. Seepage modeling with seepw an engineering methodology march 2012 edition geoslope international ltd. I am solving a transient model and changed the stepsize in the times. To make this process even smoother, first time users will benefit from the recent major update of the comsol multiphysics instruction manual. An adaptive timestepping algorithm in weakly coupled. In comsol, how to choose time step and mesh size for the. The timedependent solver in the comsol multiphysics software. Introduction 5 introduction the acdc module is used by engineers and scientists to understand, predict, and design electric and magnetic fields in statics and lowfrequency applications. For example, when you try to solve an equation youve written in the pde coefficient interface, and you set free timestep, comsol automatically choose the time. An adaptive time stepping method for transient dynamic. The new dormandprince 5 solver is an explicit time stepper with adaptive time steps, suitable for nonstiff systems of ordinary differential equations and initial value problems. The results obtained from the cfd tool are compared with inviscid shock.

The adaptive time step algorithm can potentially use a time step that is too. I am going to simulate a valveless micropump which is. Automatic time step and order selection in timedependent. Pseudo time stepping is used in transport problem to stabilize the convergence toward steady state. Finally, and unless you retrieve the time steps taken by the solver, you should. I set the time range to get data from every 10s in comsol but still it. Here an adaptive feedback regulator controls a cfl courantfriedrichslewy number which is then used for pseudo time stepping. When using manual timestepping, you can explicitly set the timestep taken. Schroeder university of gottingen from comsol to ngsolve. Note that many of the examples featured here can also be accessed via the application libraries that are built into the comsol multiphysics software and available from the file menu. Hey, i am a beginner of comsol and could anyone point me where can i find tutorial of comsol 4. Time stepping in comsol multiphysics computational science.