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Solver Solutions

1127: Improving convergence in nonlinear time dependent models

My time dependent model solves without any problem as long as I use only linear materials. How can I get it to converge with a nonlinear material?   When a time dependent solver has trouble converging, its default...
Version: 4.2 - Platform: All Platforms

1118: Resolving time-dependent waves

I am solving a time-dependent wave problem, but the solution does not look quite right. I was expecting a smooth propagating waveform but see mostly noise.   The accuracy in a model solving an equation for...
Version: 4.2 - Platform: All Platforms

1103: Frequency-dependent meshing

I am solving a wave equation over a wide range of frequencies. At the highest frequencies, I need a very fine mesh in order to resolve the wavelength. For lower frequencies, I am happy with a coarser mesh. How do...
Version: 4.1,4.2 - Platform: All Platforms

1102: Improve the stability of your contact model

In this article, you can find both general tips of how to improve convergence in your contact model and how to change solver settings of older models. ## Some General Contact Tips * When you start building a model,...
Version: 4.0,4.0a,4.1,4.2,4.2a - Platform: All Platforms

1096: COMSOL and Multithreading

This solution describes how COMSOL takes advantage of multicore computers. COMSOL supports two mutual modes of parallel operation: shared-memory parallel operations and distributed-memory parallel operations, including...
Version: 4.0,4.1,4.2 - Platform:

1095: Error: Cannot open native file

I get an error message that looks like: The following feature has encountered a problem: -Feature: Stationary Solver 1 (sol/s1)-Error: Cannot open native file. The problem is related to a Windows user name that...
Version: 4.1,4.2 - Platform: All Platforms

1062: BDF vs. Generalized Alpha time discretization

I usually use the BDF time stepping method. But I have certain examples where the generalized alpha method is much better. What numerical method is used when I choose the Generalized alpha method? Is the Generalized...
Version: 3.5a,4.0,4.0a,4.2 - Platform: All Platforms

1039: A declared function in COMSOL Multiphysics model seems to give...

I have a COMSOL Multiphysics model that solves for V. In the source term (right-hand side) of the PDE, I use an analytic function of V, f1(V), that I have defined in the Options->Functions dialog box. I do not get...
Version: 3.5a - Platform: All Platforms

1030: Error: "Out of memory"

I get an error message, that contains the words Out of memory, for example: Nonlinear solver did not converge.Time: 0Out of memory during LU factorization.Last time step is not converged. or Failed to find consistent...
Version: 3.5a,4.0,4.0a,4.1,4.2,4.2a - Platform: All Platforms

1025: Level Set method for two-phase flow, how does it compare with the...

I am new to COMSOL Multiphysics and have seen that you can use the Level Set method to track phase boundaries, for example in a rising bubble. I have heard of the Volume of Fluid method (VOF) before. What is the...
Version: All versions - Platform: All Platforms