How to Resolve Singular Matrix Error in COMSOL Transient Solver?

In summary, the conversation discusses a problem encountered while running a normal 3D incompressible flow simulation in COMSOL 3. The error message indicates that the relative error is greater than the relative tolerance for the direct solver, and the last time step is not converged. The individual is seeking advice on how to resolve this issue, mentioning that they have already tried refining the mesh and using the GMRES method with preconditioning.
  • #1
timjm
1
0
I am currently just running a normal 3D incompressible flow problem in COMSOL 3, and end up with the following error:

Error:
Time 0:
Error in residual computation:
The_relative_error_is_greater_than_the_relative_tolerance
For the direct solver.
Last time step is not converged.

How do I go about resolving this issue?

Thanks.
 
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  • #2
Hi All,

I am trying to solve a problem where the solutions are expected to be zero for a very long time.

I have refined the mesh with the maximum element size of 0.002 and am using the GMRES method with preconditioning quality of 0.01.

However, inspite of it, the system is unable to process the solution and gives an error for residual computation citing singular matrix as the problem.

Can anyone please suggest some ways to solve the problem?

Akshay
 

Related to How to Resolve Singular Matrix Error in COMSOL Transient Solver?

What is the COMSOL Transient Solver?

The COMSOL Transient Solver is a numerical simulation tool used to solve time-dependent problems in physics and engineering. It uses finite element analysis to solve partial differential equations and can handle a wide range of transient phenomena, including heat transfer, fluid dynamics, and electromagnetics.

How does the COMSOL Transient Solver work?

The COMSOL Transient Solver uses the finite element method, which involves dividing a complex problem into smaller elements and solving for the behavior of each element. The solver then combines these results to provide a solution for the entire problem over a specified time period.

What types of problems can the COMSOL Transient Solver solve?

The COMSOL Transient Solver can solve a wide range of time-dependent problems, including but not limited to heat transfer, fluid dynamics, electromagnetics, structural mechanics, and chemical reactions. It is commonly used in fields such as physics, engineering, and materials science.

What are the benefits of using the COMSOL Transient Solver?

The COMSOL Transient Solver offers several benefits, including its ability to accurately model complex phenomena, its flexibility to handle various types of physics, and its user-friendly interface. It also allows for easy visualization of results, making it a valuable tool for research and design in various industries.

Are there any limitations to the COMSOL Transient Solver?

While the COMSOL Transient Solver is a powerful tool, it does have some limitations. It may not be suitable for very large or highly nonlinear problems, and it requires a thorough understanding of the physics involved in order to accurately set up the simulation. It also requires significant computational resources, which may limit its use for some applications.

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