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Solver Solutions

1240: Manually Setting the Scaling of Variables

Transient problems often begin with all fields at an initial value of zero. During the solution the fields may increase by a great deal, or only very slightly. The default behavior of the software is to assume a...
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1213: Manually setup the geometric multigrid solver

The geometric multigrid solver accelerates the convergence of the iterative solver by solving the finite element problem on a series of meshes rather than a single one. The multigrid algorithm starts with the initial...
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1172: Solving time dependent CFD simulations

A common mistake when running transient fluid flow studies with COMSOL Multiphysics is to start the simulation with conflicting boundary conditions. Let's take a simple example to illustrate this issue. We will compute...
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1171: Manual tuning of the Contact Pair condition.

In COMSOL 4.3b, the contact pair conditions were changed to improve manual tuning of the augmented Lagrangian contact formulation. In the augmented Lagrangian method, the penalty factor controls how “hard” the...
Version: 4.3b,4.4,5.0,5.1,5.2,5.2a,5.3 - Platform: All Platforms

1157: Improve the performance of contact models built in version 4.0a or...

I have an old contact model that was built in COMSOL Multiphysics 4.0a or earlier. Now that I am using a later version of COMSOL Multiphysics, how can I take advantage of the better stability of this version in my...
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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...
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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...
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1102: Structural Contact Modeling Guidelines

This article contains guidance for solving models that include structural contact, and the procedures that should be followed to achieve a converged solution. Background Structural contact modeling is a highly...
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1096: COMSOL and Multithreading

This solution describes how COMSOL takes advantage of multicore computers. COMSOL supports two mutual modes of parallel operation: shared-memory parallelism and distributed-memory parallelism (cluster support)....
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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: 4.1,4.2,4.2a - Platform: All Platforms