Menu

Discussion Forum

New Discussion
Filtern

Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.

[Solved] Dependent Variable Field in The Pressure Acoustics, Time Explicit (pate) also discontinuous Galerkin method?

Posted 27.02.2025, 07:52 GMT-5 Acoustics & Vibrations, Modeling Tools & Definitions, Physics Interfaces Version 6.3 2 Replies

Sebastian Müller
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Hello!

When using a 'Dependent Variable Field' directly in the 'The Pressure Acoustics, Time Explicit (pate)'* physics interface, will this new extra dependent variable (from 'Dependent Variable Field') also be calculated with the discontinuous Galerkin method (dG-FEM)?? When for example using 'Dependent Variable Field' for a domain.

*which uses discontinuous Galerkin method (dG-FEM) for the standard dependent variables

Nice greetings

2 Replies Last Post 03.03.2025, 03:33 GMT-5
Sebastian Müller
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 8 months ago 27.02.2025, 18:17 GMT-5

Solved: Shape-Functions are generally choosable.

Nice Greetings

Solved: Shape-Functions are generally choosable. Nice Greetings
Kirill Shaposhnikov COMSOL Employee

Please login with a confirmed email address before reporting spam

Posted: 8 months ago 03.03.2025, 03:33 GMT-5

Hi Sebastian,

I don't know your exact intention for adding an extra shape there; I just want to mention one important thing. The time-explicit DG-FEM interfaces, like Pressure Acoustics, Time Explicit, are based on a conservation law that is solved in a quadrature-free manner, thus not involving any weak expressions. And there is no way to add an extra shape to the flux term of the conservation law the physics interface is based on. That is, if your conservation law reads "dA(u)/dt + dF(u)/dx = f", you will not be able to add the DOF 'v' to modify it to "dB(u, v)/dt + dG(u, v)/dx = g".

On the other hand, it is possible to have the DOF 'v' contributing to the right-hand side and being connected to 'u' through a weak contribution. For example, this is how the electrostatics DOFs are connected to the elastic DOFs when modelling piezoelectricity with the Elastic Waves, Time Explicit interface: the elastic DOFs (strain, velocity) enter the flux of the conservation law, while the electric potential doesn't.

Best regards Kirill

Hi Sebastian, I don't know your exact intention for adding an extra shape there; I just want to mention one important thing. The time-explicit DG-FEM interfaces, like Pressure Acoustics, Time Explicit, are based on a conservation law that is solved in a quadrature-free manner, thus not involving any weak expressions. And there is no way to add an extra shape to the flux term of the conservation law the physics interface is based on. That is, if your conservation law reads "dA(u)/dt + dF(u)/dx = f", you will not be able to add the DOF 'v' to modify it to "dB(u, v)/dt + dG(u, v)/dx = g". On the other hand, it is possible to have the DOF 'v' contributing to the right-hand side and being connected to 'u' through a weak contribution. For example, this is how the electrostatics DOFs are connected to the elastic DOFs when modelling piezoelectricity with the Elastic Waves, Time Explicit interface: the elastic DOFs (strain, velocity) enter the flux of the conservation law, while the electric potential doesn't. Best regards Kirill

Note that while COMSOL employees may participate in the discussion forum, COMSOL® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team.

Suggested Content