{ "id": "1311.4254", "version": "v2", "published": "2013-11-18T03:33:42.000Z", "updated": "2014-02-25T16:05:32.000Z", "title": "A Mixed Variational Formulation for the Wellposedness and Numerical Approximation of a PDE Model Arising in a 3-D Fluid-Structure Interation", "authors": [ "George Avalos", "Thomas J. Clark" ], "categories": [ "math.AP" ], "abstract": "We will present qualitative and numerical results on a partial differential equation (PDE) system which models a certain fluid-structure dynamics. The wellposedness of this PDE model is established by means of constructing for it a nonstandard semigroup generator representation; this representation is essentially accomplished by an appropriate elimination of the pressure. This coupled PDE model involves the Stokes system which evolves on a three dimensional domain $\\mathcal{O}$ being coupled to a fourth order plate equation, possibly with rotational inertia parameter $\\rho >0$, which evolves on a flat portion $\\Omega$ of the boundary of $\\mathcal{O}$. The coupling on $\\Omega$ is implemented via the Dirichlet trace of the Stokes system fluid variable - and so the no-slip condition is necessarily not in play - and via the Dirichlet boundary trace of the pressure, which essentially acts as a forcing term on this elastic portion of the boundary. We note here that inasmuch as the Stokes fluid velocity does not vanish on $\\Omega$, the pressure variable cannot be eliminated by the classic Leray projector; instead, the pressure is identified as the solution of a certain elliptic boundary value problem. Eventually, wellposedness of this fluid-structure dynamics is attained through a certain nonstandard variational (``inf-sup\") formulation. Subsequently we show how our constructive proof of wellposedness naturally gives rise to a certain mixed finite element method for numerically approximating solutions of this fluid-structure dynamics.", "revisions": [ { "version": "v2", "updated": "2014-02-25T16:05:32.000Z" } ], "analyses": { "keywords": [ "mixed variational formulation", "pde model arising", "fluid-structure interation", "wellposedness", "numerical approximation" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2013arXiv1311.4254A" } } }