6 papers
Unbounded eigenfunctions in the stability problem for a three-layer flow in porous media
Gelu Paşa
We study the linear stability of the displacement of three Stokes fluids with constant viscosity in a porous medium when the middle fluid is contained in a bounded region. We use t…
A non-existence result due to small perturbations in an eigenvalue problem
Gelu Paşa
We consider a well-posed eigenvalue problem on , depending on a continuous function . The boundary conditions in the points are depending on the eigenvalues. We div…
An ill-posed problem in hydrodynamic stability of multi-layer Hele-Shaw flow
Gelu Paşa}
An useful approximation for the displacement of two immiscible fluids in a porous medium is the Hele-Shaw model. We consider several liquids with different constant viscosities, in…
On the strong instability of the multi-layer Hele-Shaw flows
Gelu Paşa
We study the effects of some injection policies used in oil recovery process. The Saffman-Taylor instability occurs when a less viscous fluid is displacing a more viscous one, in a…
A strong contradiction in the multi-layer Hele-Shaw model
Gelu Paşa
The Saffman-Taylor instability occurs when a less viscous fluid is displacing a more viscous one in a rectangular Hele-Shaw cell. A surface tension on the interface between the two…
A paradox in Hele-Shaw displacements
Gelu Paşa
We study the Hele-Shaw immiscible displacements when all surfaces tensions on the interfaces are zero. The Saffman-Taylor instability occurs when a less viscous fluid is displacing…