Comparison of steady-state and transient flow conditions on reactive transport of contaminants in the vadose soil zone

Over the past few decades, due to the special features (i.e., easily produced, large-surface-area-to-volume ratio, and engineered particles with designed surface properties), nanoparticles have not only attracted great attentions from the oil and gas industry but also had various applications from drilling and completion, reservoir characterization, to enhanced oil recovery (EOR). As sensors or EOR agents, thus, fate and behavior of nanoparticles in porous media are essential and need to be investigated thoroughly. Nevertheless, most of the published review papers focus on particle transport in saturated porous media, and all of them are about steady-state flow conditions. So far, no attempts have been extended to systematically review current knowledge about nanoparticle transport in porous media with single-phase and two-phase flow systems under both steady-state and unsteady-state conditions. Accordingly, this review will discuss nanoparticle transport phenomena in porous media with its focus on the filtration mechanisms, the underlying interaction forces, and factors dominating nanoparticle transport behavior in porous media. Finally, mathematical models used to describe nanoparticle transport in porous media for both single-phase flow and two-phase flow under steady-state and transient flow conditions will be summarized, respectively.

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Summary of synoptic sampling and tracer-injection tests in the Alamosa River basin during high-flow conditions, June 1999: A sampling analysis report for modeling reactive transport of metals for the Summitville Mine, Colorado

Open-File Report ◽

10.3133/ofr03467 ◽

2003 ◽

Author(s):

Roderick F. Ortiz ◽

James W. Ball

Keyword(s):

River Basin ◽

Reactive Transport ◽

High Flow ◽

Flow Conditions ◽

Tracer Injection ◽

Synoptic Sampling

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Modelling solid transport in building drainage systems

Water Science & Technology ◽

10.2166/wst.1996.0164 ◽

1996 ◽

Vol 33 (9) ◽

pp. 9-16 ◽

Cited By ~ 4

Author(s):

John A. Swaffield ◽

John A. McDougall

Keyword(s):

Decision Making ◽

Boundary Conditions ◽

Numerical Solution ◽

Water Conservation ◽

Transient Flow ◽

Drainage System ◽

System Model ◽

Flow Depth ◽

Flow Conditions ◽

Solid Transport

The transient flow conditions within a building drainage system may be simulated by the numerical solution of the defining equations of momentum and continuity, coupled to a knowledge of the boundary conditions representing either appliances discharging to the network or particular network terminations. While the fundamental mathematics has long been available, it is the availability of fast, affordable and accessible computing that has allowed the development of the simulations presented in this paper. A drainage system model for unsteady partially filled pipeflow will be presented in this paper. The model is capable of predicting flow depth and rate, and solid velocity, throughout a complex network. The ability of such models to assist in the decision making and design processes will be shown, particularly in such areas as appliance design and water conservation.

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Flow monitoring and permeability measurement under constant and transient flow conditions

Composites Science and Technology ◽

10.1016/j.compscitech.2003.10.005 ◽

2004 ◽

Vol 64 (9) ◽

pp. 1239-1249 ◽

Cited By ~ 12

Author(s):

E. Heardman ◽

C. Lekakou ◽

M.G. Bader

Keyword(s):

Transient Flow ◽

Flow Conditions ◽

Permeability Measurement ◽

Flow Monitoring

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Pressure Analysis in the Draft Tube of a Pump-Turbine under Steady and Transient Conditions

Energies ◽

10.3390/en14164732 ◽

2021 ◽

Vol 14 (16) ◽

pp. 4732

Author(s):

Jing Yang ◽

Yue Lv ◽

Dianhai Liu ◽

Zhengwei Wang

Keyword(s):

Steady State ◽

Pressure Pulsation ◽

Transient Flow ◽

Draft Tube ◽

Simulation Method ◽

Wall Pressure ◽

Pump Turbine ◽

Steady State Condition ◽

Transient Conditions ◽

Pumped Storage

Pumped-storage power stations play a regulatory role in the power grid through frequent transition processes. The pressure pulsation in the draft tube of the pump-turbine under transient processes is important for safe operation, which is more intense than that in the steady-state condition. However, there is no effective method to obtain the exact pressure in the draft tube in the transient flow field. In this paper, the pressure in the draft tube of a pump-turbine under steady-state and transient conditions are studied by means of CFD. The reliability of the simulation method is verified by comparing the real pressure pulsation data with the test results. Due to the distribution of the pressure pulsation in the draft tube being complex and uneven, the location of the pressure monitoring points directly affects the accurate judgement of cavitation. Eight monitoring surfaces were set in the straight cone of the draft tube and nine monitoring points were set on each monitoring surface to analyze the pressure differences on the wall and inside the center of the draft tube. The relationships between the pressure pulsation value inside the center of the draft tube and on the wall are studied. The “critical” wall pressure pulsation value when cavitation occurs is obtained. This study provides references for judging cavitation occurrences by using the wall pressure pulsation value in practical engineering.

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