GERMÁN VARAS

Associate Professor
Instituto de Física, Pontificia Universidad Católica de Valparaíso
Av. Universidad 330 (Curauma), Valparaiso, Chile.
Office: +56 32 2274889
Lab: +56 32 2274987
german.varas_at_pucv.cl
Interest in: Granular Materials - MultiphaseFlow - Nonlinear Physics
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Current Research

Crater Formation

Jets impacting on a solid obstacle or confined in a cavity can develop self-sustained oscillations. Do these oscillations arise when the jet impacts a porous medium? What is the coupling with crater morphology? The present work focuses on the stability of a liquid jet when impacting a confined saturated granular bed.
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Free fall crater formation

Crater formation has been widely studied through different strategies. One of them consists on simplifying the problem to the impact of a spherical projectile on a granular layer. Due to technical limitations, experimental studies have focused independently on either the corolla formation or the deformation inside the granular bed. Hence, so far, it has not been possible to link these two processes. Here, we present an original experiment that allows to simultaneously observe the granular dynamics both above and below the granular layer in microgravity conditions.

Air invasion

We study and characterize pattern formation in immersed granular systems, when submitted to an ascending flow (gas or liquid). We are interested in the dynamics of the air-flow patterns under one or multiple injection points at the base (by imposing a constant pressure or flow-rate).
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Geometry-controlled fluidization

We explore the role of the geometry on a Hele-Shaw cell filled with grains. At constant energy we can transit from a solid or fluid modified only the boundary conditions.

Particle interactions

One particle under a granular bath behaves as if it were Brownian, will two or more particles do the same?. In this experiment we seek to see if there are (or not) interactions between two or more particles in a granular bath.
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