Diagnostics of two-phase flows with high concentration of a solid dispersed phase using fiber-optic sensors

2016 ◽  
Author(s):  
A. R. Evseev
Keyword(s):  
Fiber Optic ◽  
Fiber Optic Sensors ◽  
Dispersed Phase ◽  
High Concentration ◽  
Two Phase Flows ◽  
Two Phase

Euler-Euler Large-Eddy Simulation Approach for Non Isothermal Particle-Laden Turbulent Jet

2008 ◽  
Author(s):  
Enrica Masi ◽  
Benoiˆt Be´dat ◽  
Mathieu Moreau ◽  
Olivier Simonin
Keyword(s):  
Large Eddy Simulation ◽  
Particle Temperature ◽  
Turbulent Transport ◽  
A Priori ◽  
Particle Simulation ◽  
Dispersed Phase ◽  
Two Phase Flows ◽  
Two Phase ◽  
Eddy Simulation ◽  
Large Eddy

This paper presents an Euler-Euler Large-Eddy Simulation (LES) approach for the numerical modeling of non isothermal dispersed turbulent two-phase flows. The proposed approach is presented and validated by a priori tests from an Euler-Lagrange database, provided using discrete particle simulation (DPS) of the particle phase coupled with direct numerical simulation (DNS) of the turbulent carrier flow, in a non isothermal particle-laden temporal jet configuration. A statistical approach, the Mesoscopic Eulerian Formalism (MEF) [Fe´vrier et al., J. Fluid Mech., 2005, vol. 533, pp. 1–46], is used to write local and instantaneous Eulerian equations for the dispersed phase and then, by spatial averaging, to derive the LES equations governing the filtered variables. In this work, the MEF approach is extended to scalar variables transported by the particles in order to develop LES for reactive turbulent dispersed two-phase flows with mass and heat turbulent transport. This approach leads to separate the instantaneous particle temperature distribution in a Mesoscopic Eulerian field, shared by all the particles, and a Random Uncorrelated distribution which may be characterized in terms of Eulerian fields of particle moments such as the uncorrelated temperature variance. In this paper, the DPS-DNS numerical database is presented, LES Eulerian equations for the dispersed phase are derived in the frame of the Mesoscopic approach and models for the unresolved subgrid and random uncorrelated terms are proposed and a priori tested using the DPS-DNS database.

scholarly journals Post-Installed Fiber Optic Pressure Sensors on Subsea Production Risers for Severe Slugging Control

2015 ◽  
Author(s):  
Ammon N. Eaton ◽  
Seyed Mostafa Safdarnejad ◽  
John D. Hedengren ◽  
Kristie Moffat ◽  
Casey B. Hubbell ◽  
...  
Keyword(s):  
Fiber Optic ◽  
Flow Instability ◽  
Pressure Sensors ◽  
Offshore Structures ◽  
Fiber Optic Sensors ◽  
Mooring Lines ◽  
Two Phase ◽  
Pressure Sensing ◽  
Fbg Sensor ◽  
Control Schemes

Fiber optic sensors have gained increasing use in monitoring offshore structures. The sensors have successfully monitored flowlines, umbilicals, wells, Tension Leg Platform (TLP) tendons, production and drilling risers, and mooring lines. Fiber optic sensors are capable of monitoring strain, temperature, pressure, and vibration. While the success of fiber optic monitoring has been clearly demonstrated, the sensors are now under consideration for automation applications. This paper details the plausibility of using pressure measurements from post-installed fiber Bragg grating (FBG) sensors with Model Predictive Control (MPC) to suppress severe slugging in subsea risers. Prior control schemes demonstrate that slugging is mitigated using a topside choke valve. The most effective methods use a pressure measurement immediately upstream of the touchdown zone of the riser; however, the majority of production risers do not have pressure sensing at that location. With advances in subsea clamp design and bonding it is now possible to install a non-penetrating FBG sensor to monitor pressure near the touchdown zone without shutting down production. Stabilizing the two phase flow both reduces vibration-induced fatigue and has the potential to allow increased throughput with relaxed topside processing constraints. MPC predicts and adjusts for disturbances to avoid pressure and flow instability. The performance of the controller is influenced by sensor location, choke valve response time, and riser geometry. This study demonstrates that severe riser slugging is effectively controlled with MPC and a post-installed, non-penetrating FBG sensor.

To modeling the dynamics of system of fluid and disperse medium

2014 ◽  
Vol 10 ◽  
pp. 66-72 ◽  
Author(s):  
T.T. Lugumanov ◽  
V.S. Kuleshov
Keyword(s):  
Disperse Medium ◽  
The State ◽  
Dispersed Phase ◽  
Continuum Approach ◽  
Two Phase Flows ◽  
Two Phase ◽  
Basic Parameters ◽  
Kinetics Of

This paper reviewed literature related to the simulation of processes in systems of fluids and disperse medium. The main aspects of modeling two-phase flows using continuum approach are presented. This paper also highlights major difficulties of developing such models, the basic parameters that determine the state of dispersed phase and methods of calculating the kinetics of coagulation. An analysis was conducted of the forces acting on the particle in the flow.

Nursing Movement Monitoring System Utilizing Hetero-core Fiber Optic Sensors Embedded in Medical Thin Films

2018 ◽  
Vol 138 (12) ◽  
pp. 525-532
Author(s):  
Masahiko Ito ◽  
Yuya Koyama ◽  
Michiko Nishiyama ◽  
Emi Yanagisawa ◽  
Mariko Hayashi ◽  
...  
Keyword(s):  
Thin Films ◽  
Monitoring System ◽  
Fiber Optic ◽  
Fiber Optic Sensors ◽  
Core Fiber ◽  
Movement Monitoring
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