In this note, we show that there exist solutions of the Muskat problem that shift stability regimes: they start unstable, then become stable and finally return to the unstable regime. We also exhibit numerical evidence of solutions with medium-sized L(∞) norm of the derivative of the initial condition that develop a turning singularity.
Keywords: Muskat problem; Rayleigh–Taylor; incompressible fluid; interface; porous media.
© 2015 The Author(s) Published by the Royal Society. All rights reserved.