Special Session 56: Local and nonlocal diffusion in mathematical biology

A Navier-Stokes-Cahn-Hilliard system in 3D: well-posedness and nonlocal-to-local rates of convergence

Andrea Poiatti
University of Vienna
Austria
Co-Author(s):    Christoph Hurm, Patrik Knopf
Abstract:
In this talk I would like to present some results concerning a Navier-Stokes-Cahn-Hilliard model with singular potential describing immiscible, viscous two-phase flows with matched densities, which is referred to as the Model H, in three (and two) dimensional bounded domains. I will first concentrate on some new results of local-in-time strong well-posedness for the nonlocal version of the model H with singular potential. Namely, I will also discuss the validity of the instantaneous strict separation property of the concentration variable from pure phases, by adapting the recent result for the nonlocal Cahn-Hilliard equation in 3D by Poiatti (Anal. PDE, to appear). I will then present the nonlocal-to-local convergence of strong solutions to the model H. This means that the strong solutions to the nonlocal Model H converge to the strong solution to the local Model H as the weight function in the nonlocal interaction kernel approaches the delta distribution. To this aim, I will show some uniform bounds on the strong solutions to the nonlocal Model H, which are essential to prove the nonlocal-to-local convergence results. The novelty of this approach is that we are able to find precise convergence rates, in suitable norms, of the strong solutions to nonlocal model H to the strong solution to local model H.