What is weak form in COMSOL?

The weak formulation turns the differential equation for the heat transfer physics into an integral equation, with a test function as a localized sampling function within the integrand to clamp down the solution. Integrating the weak form by parts provides the numerical benefit of reduced differentiation order.

How do I add weak contributions to COMSOL?

Then, in the Model Builder, right-click the main interface node and, depending on the geometric entity level, select More>Weak Contribution at the domain or boundary level, Edges>Weak Contribution, Points>Weak Contribution, or Global>Weak Contribution.

Is COMSOL difficult to use?

It gives you process line options for the physics and you can learn the analysis steps easily, but in COMSOL you need to know the physics and the study details. But if you use it for just one physics always its simple to align.

What is the weak form of an equation?

Weak form – an integral expression such as a functional which implicitly contains a differential equations is called a weak form. The strong form states conditions that must be met at every material point, whereas weak form states conditions that must be met only in an average sense.

What is a weak constraint?

The weak constraint means simply that it is added directly to the weak form (sometimes there is no strong form to express your constraint, or simply it is more practical to write the weak expression directly). The usual way to add such a constraint still solving the problem consists of adding a Lagrange multiplier.

What is test function in Comsol?

While the test function, mathematically, is definded as a more-or-less often differentiable hat-function on a given region, it is displayed in most COMSOL models as something like this. rest_of_equation*(test(uTx) + test(u) + test(vty)) or similar.

What language does COMSOL use?

The Java® programming language is used to write COMSOL methods, which means that all Java® syntax and Java® libraries can be used.

Which is better Ansys vs COMSOL?

COMSOL is far more intuitive and user-friendly software (in fact, it is perhaps the most user-friendly FEA application), and it can still handle a wide range of complex issues. When it comes to structural studies and CFD simulations, however, ANSYS seems more talked about.

What is the purpose of the weak form?

The main idea of the weak form is to turn the differential equation into an integral equation, so as to lessen the burden on the numerical algorithm in evaluating derivatives. The higher the number of integral equations in the set, the better the approximation.

How do you draw geometry in Comsol?

After opening the Sketch toolbar and selecting the type of shape you want to make in the Draw section of the toolbar, you can click and move or drag the mouse in the Graphics window to form the shape.

How can I write expression in Comsol?

Click the Insert Expression button ( ) at the bottom of the section or press Ctrl+Space to insert a predefined expression or variable into the selected cell in the Value column.

How to specify a weak form PDE in COMSOL Multiphysics?

Specifying a weak form of a transient PDE involves the following three steps in the Weak Form PDE interface in COMSOL Multiphysics: The domain terms are entered in the Weak Expressions field in the Settings window of the Weak Form PDE 1 node.

What is the easiest way to implement COMSOL Multiphysics?

This gives us something very easy to implement in COMSOL Multiphysics. Start with a new 2D model with the Weak Form PDE physics interface and a Stationary study.

Does COMSOL offer support on weak form modeling?

I tried contacting COMSOL support but they say they cannot offer support on weak form modeling. This is the reason I am trying to reach out to you. Thank you Sir. The following is the reply I received from COMSOL support just now, about the above question.

What is a weak form?

About the Weak Form, Briefly For many of the different types of physics simulated with COMSOL Multiphysics, a weak formulation, or weak form, is used behind the scenes to construct the mathematical model.