Showing 2025 · math.APShow all
2 papers · 2 filters
math.AP2025
Exact Poincaré Constants in three-dimensional Annuli
Bernd Rummler, Michael Ruzicka, Gudrun Thäter
We study 3d-annuli. In our non-dimensional setting each annulus is defined via two concentrical balls with radii and . For these geometries…
math.AP2025
Natural convection in the horizontal annulus: critical Rayleigh number for the steady problem
Arianna Passerini, Bernd Rummler, Michael Ruzicka +1
For the 2D Oberbeck-Boussinesq system in an annulus we are looking for the critical Rayleigh number for which the (nonzero) basic flow loses stability. For this we consider the cor…