WorldCat Identities

Vinay, Guillaume (1978-...).

Works: 4 works in 5 publications in 2 languages and 5 library holdings
Roles: Thesis advisor, Author, Opponent
Publication Timeline
Most widely held works by Guillaume Vinay
Modélisation du redemarrage des écoulements de bruts paraffiniques dans les conduites pétrolières by Guillaume Vinay( Book )

2 editions published in 2005 in French and held by 2 WorldCat member libraries worldwide

Pipelining crude oils that contain large proportions of paraffins can cause many specific difficulties. These waxy crude oils usually exhibit high "pour point", where this temperature is higher than the external temperature conditions surrounding the pipeline. During the shutdown, since the temperature decreases in the pipeline, the gel-like structure builds up and the main difficulty concerns the issue of restarting. This phd attempts to improve waxy crude oil behaviour understanding thanks to experiment, modelling and numerical simulations in order to predict more accurately time and pressure required to restart the flow. Waxy crude oils are described as viscoplastic, thixotropic and compressible fluid. Strong temperature histiry dependence plays a prevailing role in the whole shutdown and restart process. We retain the houska model to describe the thixotropic/viscoplastic feature of the flud and compressibility is introduced in compressible flows. Governing equations are discretized using a finite volume method and the convection terms of yielded/unyielded regions. Then, the combined effects of compressibility and thixotropy have beneficial influence on the restart issue. In fact, a thixotropiic flow, not experimental results allows to validate the numerical code
Stockage de la chaleur dans un lit de particules à changement de phase by Malik Belot( )

1 edition published in 2018 in French and held by 1 WorldCat member library worldwide

This work intends to characterize heat transfer in fluid-particle flows, specifically when phase change occurs inside the particles. The proposed model takes into account the external heat resistance (heat transfer at the particle-fluid interface) and the internal heat resistance (conduction inside and at the wall of the particle, natural convection in the liquid phase of the particle, phase change). External transfer with the surrounding fluid is described by correlations linking an external Nusselt number to Reynolds and Prandtl numbers related to the surrounding fluid. Internal conduction is calculated thanks to analytical solutions. The influence of natural convection was studied on an isolated sphere for different combinations of Rayleigh and Prandtl numbers. A correlation between an internal Nusselt number, and particle Rayleigh and Prandtl numbers was established using these simulations. This correlation allows calculating the transient evolution of the average temperature of the particle when natural convection occurs. Phase change is taken into account by a Phase Field model averaged over the particle and validated by comparison with experimental and numerical studies from the literature. Finally, the whole model and the effects of the different phenomena it describes are tested on a fixed bed of particles at mesoscopic scale using a Discrete Element Method-Computional Fluids Dynamics (DEM-CFD) model. Internal conduction and natural convection gives similar quantities of total energy stored for the same Biot number, however heat transfer distribution is modified. Phase change greatly reduces the volume of storage. Increasing the Biot number leads to a greater amount of energy stored. Finally, heat transfer greatly depends on porosity distribution
Numerical simulation of a water/oil emulsion in a multiscale/multiphysics context by Mani Chandan Naru( )

1 edition published in 2021 in English and held by 1 WorldCat member library worldwide

Crude oil extraction and production lead to the formation of an emulsion of water and oil, which must be separated before being conveyed to the process installation or re-injected in the reservoir. Reducing the cost of the separation by optimizing the system requires a good understanding of the physics of emulsions. Emulsions are a multiscale/multiphysics problem involving a wide range of length scales and time scales. In particular, coalescence is a key process to be understood. Due to the difficulty of physical experimentations, numerical simulations of emulsions are appealing. Where using a single VOF function always allows coalescence at the mesh size and using different VOF functions for different drops always avoid coalescence (it is computationally expensive to use as many VOF functions as there are drops). Based on the idea that drops far enough away from one another can use the same VOF function, an efficient algorithm is developed to avoid coalescence for a large number of drops using only a few VOF functions. Furthermore, these non-coalescing drops can also be tracked over time and allowed to coalesce after the desired amount of contact time. This opens the door for efficient subgrid-scale modeling of the coalescence process. The analysis of large coalescing and non-coalescing emulsions with Bo = O(1) and Ar = O(1) have shown instabilities with a wavelength independent from the domain size characterized by the drop diameter. In coalescing emulsions filaments formation controlled by the domain size appeared. The delay in total settling time of an emulsion is also demonstrated by varying the coalescence time using the control coalescence algorithm
Simulation numérique directe des écoulements à phases dispersées by Kateryna Voronetska( )

1 edition published in 2012 in French and held by 1 WorldCat member library worldwide

The flow of immiscible fluids is a frequent issue in the petroleum industry: hydrocarbon in pipelines, separation process for production, fuel injection in engines, refinery treatment processes, etc.There are two possible approaches to model this type of flow. In the first one, the flow is described macroscopically. In this case, local phenomena (breakage or coalescence of droplets, phase slip, local compaction) are modeled thanks to analytic closure laws or empiric laws. In the second approach, the flow is simulated indirectly on a scale of droplet and we want to describe precisely the interface and the interactions between phases. We propose here to consider the second method to study liquid/liquid dispersed flows and especially the phenomena of breakage or coalescence and collision or distortion of the droplets.Thus, the main purpose of this work was the development of a direct numerical simulation code that is capable to model a liquid-liquid two-phase flow, in order to study in detail the effects of droplets coalescence and breakage. To model a two-phase flow, it is necessary to choose an appropriate interface tracking method and to develop a solver for Navier-Stokes incompressible equations to compute the velocity and pressure values. Also, a coupling method that is able to handle the discontinuous quantities at the interface has to be implemented. Our numerical tool has been validated on numerous academic test cases and applied to study the process of liquid-liquid separation
Audience Level
Audience Level
  General Special  
Audience level: 0.94 (from 0.87 for Stockage d ... to 1.00 for Modélisat ...)