Personne
Danail Obreschkow
Cette personne n’est plus à l’EPFL
Publications associées (37)
The quest for the most spherical bubble: experimental setup and data overview
Mohamed Farhat, Nicolas Dorsaz, Danail Obreschkow, Philipp Kobel, Aurèle De Bosset, Marc Tinguely
We describe a recently realized experiment producing the most spherical cavitation bubbles today. The bubbles grow inside a liquid from a point plasma generated by a nanosecond laser pulse. Unlike in previous studies, the laser is focussed by a parabolic m ...
Springer Verlag2013Energy partition at the collapse of spherical cavitation bubbles
Mohamed Farhat, Nicolas Dorsaz, Danail Obreschkow, Philipp Kobel, Aurèle De Bosset, Marc Tinguely
Spherically collapsing cavitation bubbles produce a shock wave followed by a rebound bubble. Here we present a systematic investigation of the energy partition between the rebound and the shock. Highly spherical cavitation bubbles are produced in micrograv ...
American Physical Society2012Analytical approximations for the collapse of an empty spherical bubble
Mohamed Farhat, Danail Obreschkow
The Rayleigh equation 3/2 (R) over dot + R(R) double over dot + p rho(-1) = 0 with initial conditions R(0) = R-0, (R) over dot(0) = 0 models the collapse of an empty spherical bubble of radius R(T) in an ideal, infinite liquid with far-field pressure p and ...
2012Cavitation in impacted drops and jets and the effect on erosion damage thresholds
Mohamed Farhat, Danail Obreschkow, Marc Tinguely
It is well known that metals and alloys erode at lower impact threshold velocities than expected. This was studied by Thomas and Brunton (1970) who reported “discrepancy factors” in the range 4–10. These authors suggested that liquid impact was a more sear ...
Elsevier Science Sa2012Universal Scaling Law for Jets of Collapsing Bubbles
Mohamed Farhat, Nicolas Dorsaz, Danail Obreschkow, Philipp Kobel, Aurèle De Bosset, Marc Tinguely
Cavitation bubbles collapsing and rebounding in a pressure gradient del p form a "microjet" enveloped by a "vapor jet." This Letter presents unprecedented observations of the vapor jets formed in a uniform gravity-induced del p, modulated aboard parabolic ...
2011The most spherical cavitation bubble
Mohamed Farhat, Nicolas Dorsaz, Danail Obreschkow, Philipp Kobel, Aurèle De Bosset, Marc Tinguely
Focusing a high energy pulsed laser into water is a widely used method to generate a single cavitation bubble. Such a bubble is generally assumed to collapse spherically. However, the precision of the focusing system and the effect of gravity, most often n ...
American Physical Society2011Confined shocks inside isolated liquid volumes: A new path of erosion?
Mohamed Farhat, Nicolas Dorsaz, Danail Obreschkow, Philipp Kobel, Aurèle De Bosset, Marc Tinguely
The unique confinement of shock waves inside isolated liquid volumes amplifies the density of shock–liquid interactions. We investigate this universal principle through an interdisciplinary study of shock-induced cavitation inside liquid volumes, isolated ...
American Institute of Physics2011SKA HI end2end simulation
The current status of the HI simulation efforts is presented, in which a self consistent simulation path is described and basic equations to calculate array sensitivities are given. There is a summary of the SKA Design Study (SKADS) sky simulation and a me ...
2010Techniques for generating centimetric drops in microgravity and application to cavitation studies
Mohamed Farhat, Nicolas Dorsaz, Danail Obreschkow, Philipp Kobel, Aurèle De Bosset
This paper describes the techniques and physical parameters used to produce stable centimetric water drops in microgravity, and to study single cavitation bubbles inside such drops (Parabolic Flight Campaigns, European Space Agency ESA). While the main sci ...
2009Compactness of cold gas in high-redshift galaxies
Galaxies in the early Universe were more compact and contained more molecular gas than today. In this paper, we revisit the relation between these empirical findings, and we quantitatively predict the cosmic evolution of the surface densities of atomic (HI ...
Wiley-Blackwell2009