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Experimental and Numerical Analysis of particle Migration and Patterning Behavior in a Gravel Pack

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Fluid Dynamics & Materials Processing 2023年第4期19卷 911-928页

作者： Bobo Luo Yunbin Xiong Zhuoyi Li Zhanqing Qu Fenggang Liu Tiankui Guo Zugui Yang Yina Shi Exploration and Development Research Institute Zhongyuan Oilfield CompanySINOPECPuyangChina The University of Manchester ManchesterUK College of Petroleum Engineering China University of Petroleum(East China)QingdaoChina

Due to its long lifespan and high sand-removal efficiency,gravel packing is one of the most applied sand control methods during the recovery of reservoirs with sanding problems.The blockage and retention of injected sand in a gravel pack is a complex process affected by multiple mechanisms.The majority of existing studies based on the phenomenological deep bed filtration(DBF)theory focused on the gravel pack’s overall permeability damage and failed to obtain the inner-pore particle distribution pattern.In this work,experiments and simulations were carried out to reveal the particle distribution in a gravel pack during flooding.In particular,through real-time monitoring of particle migration,the penetration depth and distribution pattern of invaded particles with different gravel-sand particle ratios,fluid viscosities and injection rates could be determined.By simplifying each unit bed element(UBE)into a pore-throat structure with four tunnels(two horizontals for discharge and two verticals for sedimentation),a new network simulation method,which combines deep bed filtration with a particle trajectory model,was implemented.Cross comparison of experimental and numerical results demonstrates the validity and accuracy of the model.

关键词： Gravel pack sand control deep bed filtration visual experiment particle trajectory

Blockage of the Deep-Sea Mining Pump Transporting Large particles with Different Sphericity

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China Ocean Engineering 2023年第2期37卷 343-352页

作者： TENG Shuang KANG Can LI Ming-hui QIAO Jin-yu DING Ke-jin School of Energy and Power Engineering Jiangsu UniversityZhenjiang 212013China Zibo Product Quality Testing Research Institute Zibo 255063China Shanghai Marine Equipment Research Institute Shanghai 200031China

The present study aims to plumb blockage of the deep-sea mining pump transporting large particles with different shapes. A numerical work was performed through combining the computational fluid dynamics(CFD) technique and the discrete element method(DEM). Six particle shapes with sphericity ranging from 0.67 to 1.0 were selected. A velocity triangle is built with the absolute, relative, and circumferential velocities of particles. Velocity triangles with absolute velocity angles ranging from 90° to 180° prevail in the first-stage impeller. With declining sphericity, more particles follow the velocity triangle with absolute velocity angles ranging from 0° to 90°, which weakens the ability of particles to pass through the flow passage. Furthermore, the forces acting on the particles traveling in the impeller passage are analyzed. Large particles, especially non-spherical ones, suffer from high centrifugal force and therefore move along the suction surface of the impeller blades. Non-spherical particles undergo great drag force as a result of large surface area. The distribution of drag force angles is featured by two peaks, and one vanishes due to blockage.As particle sphericity declines, both magnitude and angle of the pressure gradient force decrease. Variation of the drag force and the pressure gradient force causes clockwise deflection of the centripetal force, resulting in deflection and elongation of particle trajectory, which increases the possibility of blockage.

关键词： deep-sea mining pump particle sphericity velocity triangle force angle particle trajectory blockage

An SPH wave-current flume using open boundary conditions

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Journal of Hydrodynamics 2020年第3期32卷 536-547页

作者： Xing-ye Ni Wei-bing Feng Shi-chang Huang Zi-jun Hu Yong Liu Zhejiang Institute of Hydraulics and Estuary Hangzhou 310020China College of Harbor Coastal and Offshore EngineeringHohai UniversityNanjing 210098China

In this paper, a novel numerical wave-current flume is implemented based on the Smoothed particle Hydrodynamics (SPH) method. The proposed flume is more stable and computationally efficient than conventional ones because it cancels wave paddles or sponge layers while using a non-reflective open boundary condition to simultaneously generate and absorb waves and currents. Numerical tests of nonlinear regular waves interacting with steady currents in the same/opposite directions indicate that the wave-current interactions mainly affect the horizontal velocity distributions in the water body, with little influence on the vertical movements. Water particle trajectories are stretched, and the mass transportation effects are enhanced when the waves and currents are in the same direction. When the directions are opposed, the trajectories, as well as the mass transportation, are compressed, suppressed and even reversed. The applications of solitary wave-current interaction over a submerged bump further show that the relative direction between the wave and the current has remarkable influence on the wave breaking pattern over an underwater obstacle.

关键词： Smoothed particle hydrodynamics(SPH) wave-current interaction wave-current flume open boundary condition particle trajectory

Design of the stripping unit and the electromagnetic analysis unit for the E//B NPA on HL-2A/2M tokamak

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Plasma Science and Technology 2022年第6期24卷 7-13页

作者：臧临阁屈玉凡罗圆林炜平 Southwestern Institute of Physics Chengdu 610218People's Republic of China Key Laboratory of Radiation Physics and Technology of the Ministry of Education Institute of Nuclear Science and TechnologySichuan UniversityChengdu 610064People's Republic of China

An E//B neutral particle analyzer is under development for fast ion diagnosis on HL-2A/2 M tokamak.The stripping unit is composed of a stripping room(equipped with two differential tubes and a gas supply bellows),a vacuum chamber and a vacuum pumping system.The stripping efficiency of the stripping room is calculated in the form of global efficiency R×f_(+1),where R is the non-scattered-away rate and f_(+1)is the fraction of charge state+1.The magnetic field of the E//B analyzer is produced with a permanent magnet.The yoke and the poles of the magnet are made of mild steel and the magnet plates are made of Nd Fe B.The magnetic poles are specially designed to focus the ion trajectories and to increase the use rate of the magnet.The shape of the magnet and the electric plates are carefully designed so that the ions are dispersed into two lines of H^(+) and D^(+) on the detector plane.For each line,the energy increases from 10 to 200 ke V from one side to another.

关键词： fast ion stripping room particle trajectory neutral particle analysis

Interactions of nonlinear gravity waves and uniform current in Lagrangian system

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Acta Oceanologica Sinica 2009年第1期28卷 89-98页

作者： HSU Hung-Chu CHEN Yang-Yih LI Meng-Syue TSENG Wen-Jer Tainan Hydraulics Laboratory National Cheng Kung University Department of Marine Environment and Engineering National Sun Yat-Sen University Department of Civil Engineering Cheng Shiu University

The particle trajectory on a weakly nonlinear progressive surface wave obliquely interacting with a uniform current is studied by using an Euler-Lagrange transformation.The third-order asymptotic solution is a periodic bounded function of Lagrangian labels and time,which imply that the entire solution is uniformly-valid.The explicit parametric solution highlights the trajectory of a water particle and mass transport associated with a particle displacement can now be obtained directly in Lagrangian form.The angular frequency and Lagrangian mean level of the particle motion in Lagrangian form differ from those of the Eulerian.The variations in the water particle orbits resulting from the oblique interaction with a steady uniform current of different magnitudes are also investigated.

关键词： Lagrangian particle trajectory nonlinear water wave current drift velocity

A third-order asymptotic solution of nonlinear standing water waves in Lagrangian coordinates

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Chinese Physics B 2009年第3期18卷 861-871页

作者：陈益处许弘莒 Department of Marine Environment and Engineering National Sun Yat-Sen University Tainan Hydraulics Laboratory National Cheng Kung University

Asymptotic solutions up to third-order which describe irrotational finite amplitude standing waves are derived in Lagrangian coordinates. The analytical Lagrangian solution that is uniformly valid for large times satisfies the irrotational condition and the pressure p = 0 at the free surface, which is in contrast with the Eulerian solution existing under a residual pressure at the free surface due to Taylor＇s series expansion. In the third-order Lagrangian approximation, the explicit parametric equation and the Lagrangian wave frequency of water particles could be obtained. In particular, the Lagrangian mean level of a particle motion that is a function of vertical label is found as a part of the solution which is different from that in an Eulerian description. The dynamic properties of nonlinear standing waves in water of a finite depth, including particle trajectory, surface profile and wave pressure are investigated. It is also shown that the Lagrangian solution is superior to an Eulerian solution of the same order for describing the wave shape and the kinematics above the mean water level.

关键词： Lagrangian nonlinear standing waves particle trajectory Lagrangian wave frequency

Peristaltic transport of rheological fluid:model for movement of food bolus through esophagus

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Applied Mathematics and Mechanics(English Edition) 2012年第3期33卷 315-332页

作者： J.C.MISRA S.MAITI Department of Mathematics Institute of Technical Education and ResearchSiksha 'O' Anusandhan UniversityBhubaneswar 751030India School of Medical Science and Technology & Center for Theoretical Studies Indian Institute of TechnologyKharagpur 721302India

Fluid mechanical peristaltic transport through esophagus is studied in the paper. A mathematical model has been developed to study the peristaltic transport of a rheological fluid for arbitrary wave shapes and tube lengths. The Ostwald-de Waele power law of a viscous fluid is considered here to depict the non-Newtonian behaviour of the fluid. The model is formulated and analyzed specifically to explore some important information concerning the movement of food bolus through esophagus. The analysis is carried out by using the lubrication theory. The study is particularly suitable for the cases where the Reynolds number is small. The esophagus is treated as a circular tube through which the transport of food bolus takes place by periodic contraction of the esophageal wall. Variation of different variables concerned with the transport phenomena such as pressure, flow velocities, particle trajectory, and reflux is investigated for a single wave as well as a train of periodic peristaltic waves. The locally variable pressure is seen to be highly sensitive to the flow index ＂n＂. The study clearly shows that continuous fluid transport for Newtonian/rheological fluids by wave train propagation is more effective than widely spaced single wave propagation in the case of peristaltic movement of food bolus in the esophagus.

关键词： non-Newtonian fluid food bolus esophagus peristaltic transport flow reversal single wave wave train particle trajectory

particle Trajectories in Nonlinear Water Wave on Uniform Current

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China Ocean Engineering 2008年第4期22卷 611-621页

作者： Hung-Chu HSU Yang-Yih CHEN Chia-Yan CHENG Wen-Jer TSENG Tainan Hydraulics Laboratory National Cheng Kung University Department of Marine Environment and Engineering National Sun Yat-Sen University Coastal and Offshore Resources Research Center Fisheries Research Institute Department of Civil Engineering Cheng Shiu University

The study in this paper is focusing on trajectories of particles in the irrotational progressive water waves coexisting with uniform current. The parametric equations of particle trajectories over a range of levels in a Lagrangian type of description are developed analytically via the Euler-Lagrange transformation. The Lagrangian wave period of particle motion differing from the Eulerian wave period and the mass transport can also be obtained directly. The third-order solution of particle trajectory exhibits that they do not move in closed orbital motion but represent a net movement that decreases exponentially with the water depth. Uniform current is found to have significant effect on the trajectories and drift velocity of gravity waves. Overall, the influence of increased uniform current is to increase the relative horizontal distance traveled by a particle, as well as the magnitude of the time-averaged drift velocity on the free surface. For adverse current cases, a reverse behavior is found. The obtained third-order solutions satisfy the irrotational condition contrasted to the Gerstner waves and are verified by reducing to those of two-dimensional gravity waves in Lagrangian coordinates.

关键词： wave current Lagrangian Euler- Lagrange transformation particle trajectory

NUMERICAL SIMULATION OF THREE DIMENSIONAL GAS-particle FLOW IN A SPIRAL CYCLONE

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Applied Mathematics and Mechanics(English Edition) 2006年第2期27卷 247-253页

作者：王灿星易林 College of Mechanical and Energy EngineeringZhejiang University Hangzhou 310027 P. R. China

The three-dimension gas-particle flow in a spiral cyclone is simulated nu- merically in this paper. The gas flow field was obtained by solving the three-dimension Navier-Stokes equations with Reynolds Stress Model （RSM）. It is shown that there are two regions in the cyclone, the steadily tangential flow in the spiral channel and the combined vortex flow in the centre. Numerical results for particles trajectories show that the initial position of the particle at the inlet plane substantially affects its trajectory in the cyclone. The particle collection efficiency curves at different inlet velocities were obtained and the effects of inlet flow rate On the performance of the spiral cyclone were presented. Numerical results also show that the increase of flow rate leads to the increase of particles collection efficiency, but the pressure drop increases sharply.

关键词： spiral cyclone numerical simulation particle trajectory collection efficiency