Continuous-phase fluid velocity measurement for oil field flows using local optical probe and tracing method

2000 ◽  
Author(s):  
Rogerio T. Ramos ◽  
Andrew Holmes
Author(s):  
Ophe´lie Caballina ◽  
Eric Climent ◽  
Jan Dusˇek

When bubbles are continuously released from a located source at the bottom of a fluid layer initially at rest, a plume is produced. The motion of the carrier fluid is initiated and driven by buoyancy of the bubble cloud. In the present study, a detailed analysis of the bubble plume transition is investigated. The continuous phase flow is obtained by direct numerical resolution of Navier-Stokes equations forced by the presence of bubbles. Collective effects induced by the presence of bubbles are modelled by a spatio-temporal distribution of momentum. Time evolution of the dispersed phase is solved by lagrangian tracking of all the bubbles. Focused on the description of plume transition, several configurations (plume widths, fluid viscosity, injection rate) are investigated. During the laminar ascension of the plume, fluid velocity profiles can be non-dimensionalised on a single auto-similar evolution. Dimensional analysis provides a prediction of the limit rising velocity of the plume top. This prediction has been confirmed by our numerical simulations. Furthermore, our first results point out the symmetry breaking induced by plume instability which appears beyond a critical transition height. Various data show that the Grashof number based on injection conditions is the key parameter to predict the transition of the plume. Our results agree very well with recent experimental data. Comparison with experiments on thermal plumes in air shows that the bubble plume is more unstable. This feature should be related to the lack of diffusion in the lagrangian transport of density gradient by the bubble cloud and to the slip velocity between the two phases.


2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Mathieu Alonzo ◽  
Anthony Lefebvre ◽  
Zhujun Huang ◽  
Stéphane Gluck ◽  
Cartellier Alain

Author(s):  
David J. Schmidt ◽  
Goodarz Ahmadi

The motions of deformable liquid droplets in a turbulent spray are simulated numerically using a three-dimensional joint, one-way coupled Lagrangian-Eulerian simulation technique. The instantaneous fluid velocity and velocity gradient of the continuous phase is simulated with the use of an advanced Navier-Stokes based Lagrangian PDF (probability density function) stochastic model. This model is used to simulate the turbulent structures known to exist within the shear layers of a plane and axisymmetric jet. The mean fluid velocity field is obtained with the use of the FLUENT computer code, using the Reynolds stress transport turbulence model. The dilute phase is modeled as a series of continuously injected spheres, with no particle-particle interactions. Forces on the particles include nonlinear Stokes drag and Saffman lift. Multiple particle trajectories are then numerically evaluated by integrating the equations of motion using the computed fluid velocity field as input. Ensembles of particle trajectories are generated for a point and line source emanating near the inlet to the spray chamber. Test cases for an axisymmetric jet are considered. Results show agreement in the instantaneous flow field for all lower statistical moments. For a turbulent spray consisting of nonevaporating spherical droplets, good qualitative agreement is seen in the overall dispersion of droplets as well as the corresponding spray angle.


Author(s):  
Mohammad Rahnama ◽  
Mazyar Salmanzadeh ◽  
Goodarz Ahmadi

Particle transport and deposition in a turbulent channel flow simulated by the Large Eddy simulations (LES) were studied. Particular attention was paid to the effect of subgrid scales (SGS) turbulence fluctuation on particle motion. Finite volume method was used for finding instantaneous filtered fluid velocity fields of LES of the continuous phase in the channel. Selective structure function model was used to account for the subgrid-scale Reynolds stresses. It was shown that the LES was capable of capturing the turbulence near wall coherent eddy structures. Particle motions were investigated using a Lagrangian particle tracking approach with inclusion of the Stokes drag, lift, Brownian and gravity forces. Effects of SGS of turbulence fluctuations on deposition rate of different size particles were studied. It was shown that the inclusion of the SGS turbulence fluctuations improves the model predictions for particle deposition rate especially for small particles.


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