Concept

Free surface

Related publications (87)

Experimental investigation of the sloshing motion of the water free surface in the draft tube of a Francis turbine operating in synchronous condenser mode

François Avellan, Elena Vagnoni, Arthur Tristan Favrel, Loïc Andolfatto

Hydropower units may be required to operate in condenser mode to supply reactive power. In this operating mode, the water level in the turbine or pump-turbine is decreased below the runner by closing the guide vanes and injecting pressurized air. While ope ...

2018

Jetting from cavitation bubbles due to multiple shockwaves

Mohamed Farhat, Outi Supponen

We present experimental observations of microjets formed by cavitation microbubbles. An underwater electric discharge, applied beneath a flat free surface, produces a primary compression wave, which undergoes several phase inversions upon reflections from ...

AMER INST PHYSICS2018

Hydrodynamics of a periodically wind‑forced small and narrow stratified basin: a large‑eddy simulation experiment

Alfred Johny Wüest, Damien Bouffard, Hugo Nicolás Ulloa Sánchez, Oscar Rodrigo Sepúlveda Steiner, Serban George Constantinescu, Kyoung Sik Chang

We report novel results of a numerical experiment designed for examining the basin-scale hydrodynamics that control the mass, momentum, and energy distribution in a daily wind-forced, small thermally-stratified basin. For this purpose, the 3-D Boussinesq e ...

2018

Experimental comparison of tsunami generated by viscoplastic and granular slides.

Zhenzhu Meng

Tsunami induced by subaerial landslides threatens coastal areas. The waves have mostly been studied in the laboratory using sliding blocks or granular media hitting a water body, but none of these materials makes it possible to understand how sliding mass’ ...

2018

Rebounds of deformed cavitation bubbles

Mohamed Farhat, Danail Obreschkow, Outi Supponen

Presented here are experiments clarifying how the deformation of cavitation bubbles affects their rebound. Rebound bubbles carry the remaining energy of a bubble following its initial collapse, which dissipates energy mainly through shock waves, jets, and ...

AMER PHYSICAL SOC2018

Understanding turbulent free-surface vortex flows using a Taylor-Couette flow analogy

Giovanni De Cesare

Free-surface vortices have long been studied to develop an understanding of similar rotating flow phenomena observed in nature and technology. However, a complete description of its turbulent three-dimensional flow field still remains elusive. In contrast, ...

2018

Fluid dynamics of flow fields in a disposable 600-mL orbitally shaken bioreactor

Florian Maria Wurm, David Hacker, Dominique Terry Monteil Jr, Likuan Zhu

Orbitally shaken bioreactors (OSRs) are commonly used for the cultivation of mammalian cells in suspension. Here we conducted a three-dimensional computational fluid dynamics (CFD) simulation to characterize the fluid field in the disposable 600-mL orbital ...

Elsevier2018

Dynamics of falling films on the outside of a vertical rotating cylinder: waves, rivulets and dripping transitions

François Gallaire, Nicolas Igor Jacques Kofman

Falling liquid films on the underside of a plate or on the outside of a rotating cylinder are subject to a destabilizing body force. The evolution of the film topology is determined by interactions between the Kapitza and the Rayleigh-Taylor instability, l ...

Cambridge University Press2017

Characteristics of solitary waves on a falling liquid film sheared by a turbulent counter-current gas flow

Nicolas Igor Jacques Kofman

We report an experimental investigation of a falling water film sheared by a turbulent counter-current air flow in an inclined rectangular channel. Film thickness and wave velocity measurements associated with visual observation are conducted to study the ...

Elsevier2017

On the sloshing free surface in the draft tube cone of a Francis turbine operating in synchronous condenser mode

François Avellan, Elena Vagnoni, Loïc Andolfatto

Hydropower plants may be required to operate in synchronous condenser mode in order to supply reactive power to the grid for compensating the fluctuations introduced by the intermittent renewable energies such wind and solar. When operating in this mode, t ...

2017

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