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COMSOL has built in logic to handle most multiphysics problems when the predefined multiphysics couplings are used ensuring that the model solves correctly. If ...

The direct solver is used as a linear system solver. Navier-Stokes is a nonlinear problem per se. As such a nonlinear method is used around each ...

Solvers and multigrid methods expert Wolfgang Joppich explores the benefits and limitations of solution methods. × Warning Your internet explorer is in compatibility mode and may not be displaying the website correctly.

The direct solvers used by COMSOL are the MUMPS, PARDISO, and SPOOLES solvers. All of the solvers are based on LU decomposition.

MUMPS (multifrontal massively parallel sparse direct solver) (the default). ... the nested dissection faster when COMSOL Multiphysics runs multithreaded), ...

The MUMPS and SPOOLES solvers run distributed when running COMSOL Multiphysics in distributed mode (on clusters, for example). All linear system solvers ...

22.11.2013 · November 11, 2013. In this blog post we introduce the two classes of algorithms that are used in COMSOL to solve systems of linear equations that arise when solving any finite element problem. This information is relevant both for understanding the inner workings of the solver and for understanding how memory requirements grow with problem size.

It also discusses the Convergence Criteria for Iterative Solvers and Selecting a Preconditioner for an Iterative Linear System Solver. Linear in the COMSOL ...

Sep 25, 2016 · The COMSOL blogs is a good place to start, for example this: www.comsol.com/blogs/solutions-linear-systems-equations-direct-iterative-solvers/ The direct solver is used as a linear system solver. Navier-Stokes is a nonlinear problem per se. As such a nonlinear method is used around each linear step.

These solvers can roughly be ordered according to their memory usage and computational time per iteration (with least memory and time first): Conjugate gradients, BiCGStab, TFQMR, GMRES, and then FGMRES. The solvers that require less memory and computational time per iteration typically are less robust and not applicable to all problem types.

Faster ODE Solvers and Explicit Time Solver Dormand-Prince 5 (Runge-Kutta 4/5) The time stepping algorithms have been optimized for solving ODEs and initial value problems more efficiently. Certain problem classes can be an order of magnitude faster to solve. The new Dormand-Prince 5 solver is an explicit time-stepper with adaptive time steps ...

Aug 30, 2019 · Enter the solver suggestions in COMSOL Multiphysics®. Automatic Time Step and Order Selection in Time-Dependent Problems June 20, 2019 Here’s an intro to the time-dependent solver log in COMSOL Multiphysics® and an in-depth look at the theory behind discrete time-stepping schemes and optimal time steps and discretization orders.

30.08.2019 · When solving a model, you may encounter a varying time step and discretization order, or NLfail or Tfail could be greater than 0. Use these strategies to improve the efficiency of the simulation. How to Perform a Sensitivity Analysis in COMSOL Multiphysics®

COMSOL Multiphysics ® version 6.0 includes improved mesh adaptation for curl element formulations, performance improvements for cluster computations, and Component Mode Synthesis for modal reduction. Learn about all of the updates relating to …

28.09.2016 · Solvers in COMSOL. Posted Sep 25, 2016, 6:52 a.m. EDT Fluid, Computational Fluid Dynamics (CFD), Results & Visualization, Studies & Solvers 2 Replies

Linear Static Finite Element Problem

The process of solving a problem in COMSOL Multiphysics is a hierarchy. The Study node ( ) is the coarsest level (the top level).

Distributed Solution Data Storage on Clusters

When you use an iterative solver, COMSOL Multiphysics estimates the error of the solution while solving. Once the error estimate is small enough, as determined by the convergence criterion (20-16) the software terminates the computations and returns a solution.

Gain an understanding of the studies and solvers in COMSOL Multiphysics® and learn how to reach convergence for your multiphysics problems on the COMSOL ...

COMSOL Blog. Moore’s Law for Solvers. by David Kan. September 12, 2012. At the heart of any simulation software are the solvers. Those are things that take geometry/mesh/physics to the computational results. While it’s convenient to think about solvers in terms of the type of study ...

There are different solvers in COMSOL: Dependent Variables Solver, Stationary Solver , etc. but I don't know when or where is it better to use one more than ...

Nov 22, 2013 · In this blog post we introduce the two classes of algorithms that are used in COMSOL to solve systems of linear equations that arise when solving any finite element problem. This information is relevant both for understanding the inner workings of the solver and for understanding how memory requirements grow with problem size.