Szimuláció és Optimalizáció Szeminárium, 2013. 01. 21.

Alexander Linke (WIAS Berlin)

On Robust Discretizations for Coupled Flow Problems

2013. 01. 21. 12:00

Location: Járműipari Kutató Központ előadóterem - Inno-Share épület II. emelet

Robust discretization of coupled flow problems like Rayleigh-Benard convection or the Nernst-Planck-Poisson-Stokes system in micro fluidics remains to be a challenging problem. Due to the multi-physics character of such flow processes, discretizations for the full nonlinearly coupled system have to respect many different qualitative properties of the underlying physical processes at the same time, e.g., discrete maximum principles for temperature or species concentrations and discrete mass conservation.

This talk will focus on the problem of poor mass conservation in coupled flow problems.

In principle, poor mass conservation is a well-known numerical instability in the context of the incompressible Navier-Stokes equations that develops whenever irrotational forces enter the force balance of the momentum equations. But often the impact of poor mass conservation is underestimated in practice and lack of robustness of numerical codes is explained di fferently. The talk will demonstrate the dramatic impact of poor mass conservation in coupled fl ows, due to partially irrotational forcing terms like buoyancy.