Publications related to Multiphase flow

Rock-Flow Cell Parameters Evaluation Using Ultrasound Doppler Velocimetry

Giovanni De Cesare, Javier Neves da Silva, Andre Luis Stakowian

This work presents a study of two-phase flow generated inside a rock-flow cell setup. It is characterized by a pipe section filled with fluid (oil in our studies) that is put into oscillation around its mass centre by an electric motor. This type of appara ...

2023

Measurement and modelling of dynamic fluid saturation in carbon reinforcements

Véronique Michaud, Baris Çaglar, Helena Luisa Teixido Pedarros, Guillaume Clément Broggi

We propose a methodology to monitor the progressive saturation of a non-translucent unidirectional carbon fabric stack through its thickness by means of X-ray radiography and extract the dynamic saturation curves using image analysis. Four constant flow ra ...

2023

Revisiting the role of friction coefficients in granular collapses: confrontation of 3-D non-smooth simulations with experiments

Gauthier Paul Daniel Marie Rousseau

In this paper, transient granular flows are examined both numerically and experimentally. Simulations are performed using the continuous three-dimensional (3-D) granular model introduced in Daviet & Bertails-Descoubes (ACM Trans. Graph., vol. 35, no. 4, 20 ...

Cambridge University Press2023

Flow pattern observations and flow pattern map for adiabatic two-phase flow of carbon dioxide in vertical upward and downward direction

Jürg Alexander Schiffmann, Rémi Revellin, David Schmid

A test facility to investigate flow pattern transitions of vertical two-phase flow of CO2 has been built within the scope of the high-luminosity detector upgrades at the European Organization for Nuclear Research (CERN). Adiabatic flow pattern observations ...

2022

Simulation and experimental validation of pulsating heat pipes

John Richard Thome, Jackson Braz Marcinichen, Philippe Aubin, Filippo Cataldo

The one-dimensional transient numerical code of JJ Cooling Innovation has been significantly improved to simulate the thermal/hydraulic performance of pulsating heat pipes (PHPs). Using a mechanistic approach, the liquid slug and vapor plug flows and their ...

PERGAMON-ELSEVIER SCIENCE LTD2021

Numerical analysis for detecting head losses in trifurcations of high head in hydropower plants

François Avellan, Ramiro Gustavo Ramirez Camacho

Many different types of branching have been developed, such as bifurcation, trifurcation, and manifolds, among others. These configurations are used in penstocks to transport water from surge tanks to power houses in order to feed several turbines at the s ...

Pergamon-Elsevier Science Ltd2019

Numerical Modelling of Two-Phase Flow with Moving Boundary Fitted Meshes

Erik Gros

In this thesis, a computational approach is used to study two-phase flow including phase change by direct numerical simulation. This approach follows the interface with an adaptive moving mesh. The incompressible Navier-Stokes equations are solved, in tw ...

EPFL2018

CFD as an Enginer's Tool for Investigation of Large-Scale-Flow-Phenomena "at Land, Sea and Air"

Michel Deville

Along with prospective fashion of solving the engineering-tasks (if development would allow us a such approach while answering the technology-questions of some project in future), goes alternatively corrective performance of those engineering tools, used t ...

SPRINGER INTERNATIONAL PUBLISHING AG2018

Flow field in a reservoir subject to pumped-storage operation - in situ measurement and numerical modeling

Anton Schleiss, Giovanni De Cesare, Michael Müller

In pumped-storage reservoirs, turbulent kinetic energy input from plant operation can be considerably high. Flow velocities were measured by Acoustic Doppler Current Profilers near the intake/outlet structure to describe flow patterns induced by pumped-sto ...

2018

Pressure drop prediction in annular two-phase flow in macroscale tubes and channels

John Richard Thome, Andrea Cioncolini

A new prediction method for the frictional pressure drop in annular two-phase flow is presented. This new prediction method focuses on the aerodynamic interaction between the liquid film and the gas core in annular flows, and explicitly takes into account ...

Pergamon-Elsevier Science Ltd2017

An updated three-zone heat transfer model for slug flow boiling in microchannels

John Richard Thome, Mirco Magnini

This work proposes a novel physics-based model for the fluid mechanics and heat transfer associated with slug flow boiling in horizontal circular microchannels to update the widely used three-zone model of Thome et al. (2004). The heat transfer model has a ...

Pergamon-Elsevier Science Ltd2017

Experimental investigation of the mass flow gain factor in a draft tube with cavitation vortex rope

François Avellan, Arthur Tristan Favrel, Christian Landry, Andres Müller, Sébastien Alligné, Keita Yamamoto

At off-design operating operations, cavitating flow is often observed in hydraulic machines. The presence of a cavitation vortex rope may induce draft tube surge and electrical power swings at part load and full load operations. The stability analysis of t ...

2017

Two-phase operational maps, pressure drop, and heat transfer for flow boiling of R236fa in a micro-pin fin evaporator

John Richard Thome, Navid Borhani, Mirco Magnini, Chiara Falsetti, Hamideh Jafarpoorchekab

Cooling the new generation of 3D high power electronic chips is one of the leading challenges in microelectronics, as it is a key to achieve high computational performance at lower cooling system power consumption, thus reducing the operating cost. Two-pha ...

Pergamon-Elsevier Science Ltd2017

Statistical parametric mapping of stimuli evoked changes in total blood flow velocity in the mouse cortex obtained with extended-focus optical coherence microscopy

Theo Lasser, Paul James Marchand, Vincent Khashayar Shamaei, Arno Pino Bouwens, Tristan Bolmont, Daniel Pawel Szlag, Jérôme Extermann, David Nguyen

Functional magnetic resonance (fMRI) imaging is the current gold-standard in neuroimaging. fMRI exploits local changes in blood oxygenation to map neuronal activity over the entire brain. However, its spatial resolution is currently limited to a few hundre ...

Optical Soc Amer2017

URANS Models for the Simulation of Full Load Pressure Surge in Francis Turbines Validated by Particle Image Velocimetry

François Avellan, Arthur Tristan Favrel

Due to the penetration of alternative renewable energies, the stabilization of the electrical power network relies on the off-design operation of turbines and pump-turbines in hydro-power plants. The occurrence of cavitation is however a common phenomenon ...

American Society of Mechanical Engineers2017

Parallelization of microfluidic flow-focusing devices

Esther Amstad

Microfluidic flow-focusing devices offer excellent control over fluid flow, enabling formation of drops with a narrow size distribution. However, the throughput of microfluidic flow-focusing devices is limited and scale-up through operation of multiple dro ...

Amer Physical Soc2017

Studies of Two-Phase Flow at a Chute Aerator with Experiments and CFD Modelling

Michael Pfister

The chute aerator of a spillway is a structure in such a sense that air is, in the intense emulsification, entrained into the high-velocity water flow. Correctly predicting the air entrainment and two-phase flow pattern at the aerator would contribute to r ...

Hindawi Limited2016

A CFD study of the parameters influencing heat transfer in microchannel slug flow boiling

John Richard Thome, Mirco Magnini

Boiling heat transfer in microchannels has been investigated extensively in the last two decades. However, most results from independent experimental studies display a substantial disagreement on the influence of the flow conditions and mechanisms on the h ...

Elsevier France-Editions Scientifiques Medicales Elsevier2016

Flow Boiling Pressure Drop and Heat Transfer of Refrigerants in Multi-microchannel Evaporators under Steady and Transient States

Houxue Huang

Multi-microchannel evaporators used for the cooling of high heat flux electronics have been of interest to both industry and academia for more than a decade. Such interest has sparked a large number of research studies on the flow boiling pressure drop and ...

EPFL2016

Experimental investigation on flow boiling pressure drop and heat transfer of R1233zd(E) in a multi-microchannel evaporator

John Richard Thome, Navid Borhani, Houxue Huang

An experimental study on flow boiling pressure drop and heat transfer of a new environmentally friendly refrigerant R1233zd(E), in a parallel multi-microchannel evaporator was carried out. The silicon microchannels evaporator was 10 mm long and 10 mm wide, ...

Pergamon-Elsevier Science Ltd2016