Stationary Vs. Moving Mesh
 

This is a general question.

Let's say I have an object with a flexible boundary. Over time, the boundary changes its shape. Or I have an object like an oscillating airfoil that moves within a fluid (I will solve it in inertial coordinate frame).

In a general FEM implementation, how would I go about solving this?

Do I need a stationary mesh through which the fluids moves (Eulerian) and a moving mesh (Lagrangian) that's attached to the body? Where are the nodes located and how do I implement the boundary conditions? Is there some type of "communication" between the stationary mesh and the moving mesh?

I understand I could use an immersed boundary method approach, but I want a more basic approach.

Thanks for the help.

Try looking into "Arbitrary Lagrangian-Eulerian" methods.