Modeling Horizontal Salt Cavern Leaching in Bedded Salt Formations

SPE Journal ◽  
2022 ◽  
pp. 1-12
Author(s):  
Quanshu Zeng ◽  
Zhiming Wang ◽  
Jinchao Wang ◽  
Qiqi Wanyan ◽  
Guosheng Ding ◽  
...  
Keyword(s):  
Concentration Distribution ◽  
Coupled Model ◽  
Flow Region ◽  
Cavity Expansion ◽  
Injection Point ◽  
Salt Cavern ◽  
Transport Dynamics ◽  
Brine Transport ◽  
Relative Errors ◽  
And Diffusion

Summary The leaching of a salt cavern will trigger a series of rock-fluid interactions, including salt rock dissolution, cavity expansion, and brine transport caused by convection, turbulence, and diffusion effects. These interactions have influences on one another. The primary objectives of this study include developing a 3D multiphysical coupled model for horizontal salt cavern leaching and quantifying these interactions. The species transport equation and standard κ-ε equation were combined to describe the brine transport dynamics within the cavity. Based on the velocity and concentration distribution characteristics predicted, the interface movement equation implemented with mesh deformation techniques was applied to describe the cavity expansion. Next, the Volgograd cavern monitored data were collected for model validation. The predicted results are consistent with the field data. The average relative errors are 11.0% for brine displacing concentration and 4.5% for cavity volume. The results suggest that the cavity can be divided into three regions, including the main flow region, circulation region, and reflux region. The results also suggest that the brine concentration distribution is relatively uniform. With the dissolution threshold angle and anisotropic dissolution rates considered, the resultant cavity cross section is crown top and cone bottom. The results also show that the cavity can be divided into dissolution and erosion sections according to its position relative to the injection point.

Numerical Simulation of Plug Discharge with Dissolved Oxygen Convection and Diffusion

2012 ◽  
Vol 433-440 ◽  
pp. 1920-1925
Author(s):  
Ze Gao Yin ◽  
Le Wang ◽  
Jin Xiong Zhang ◽  
Xian Wei Cao
Keyword(s):  
Mathematical Model ◽  
Dissolved Oxygen ◽  
Oxygen Concentration ◽  
Dissipation Rate ◽  
Concentration Distribution ◽  
Coupled Model ◽  
Computational Results ◽  
Dissolved Oxygen Concentration ◽  
Velocity Pressure ◽  
And Diffusion

In Fluent, the 3-D RNG k- ξ mathematical model is employed to compute the plug discharge, and dissolved oxygen convection and diffusion model is established to simulate the concentration distribution of dissolved oxygen with user defined scalar method. Velocity, pressure, turbulence kinetic energy, turbulence dissipation rate and dissolved oxygen concentration are computed. Then, velocity, pressure and dissolved oxygen concentration are compared with the data of physical model, and they agree with each other approximately, showing it is valid and reliable to compute the plug discharge and dissolved oxygen concentration with the coupled model. Furthermore, the characteristics of hydraulic factors including dissolved oxygen concentration are analyzed and generalized based on the computational results.

A method for predicting Mach stem height in steady flows

2021 ◽  
pp. 095441002110015
Author(s):  
Song-Guk Choe
Keyword(s):  
Analytical Model ◽  
Slip Line ◽  
Flow Region ◽  
Rocket Engines ◽  
Steady Flows ◽  
Mach Stem ◽  
Stem Height ◽  
Mach Numbers ◽  
Relative Errors ◽  
Cfd Method

The prediction of Mach stem height can be important in the design of supersonic intake in supersonic and hypersonic flows. It is also important because of the progress in aircraft and rocket engines. An analytical method of predicting the Mach stem height is necessary in theoretical field of shock reflection and is the basis of the comparable computational fluid dynamics (CFD) method. A method for predicting the Mach stem height in steady flows is performed based on the earlier models. In this article, an analytical model for predicting the Mach stem height is improved based on two main assumptions: one is the calculation of the triple point deflection angle when the Mach stem is an oblique shock and the other is about the shape of the free part of the slip line. Under these assumptions, the relations predicting of Mach stem height in two-dimensional steady flow are derived based on the advanced averaging method of the subsonic flow region. The Mach stem heights are decided solely for the incoming flow Mach numbers and the wedge angles by the improved analytical model. As a result, the Mach stem heights by the model of this article are found to agree well with experimental results at lower Mach numbers, but there are relative errors at higher Mach numbers. The convexity of the slip line is also considered.

Detailed Electrochemistry and Gas Transport in a SOFC Anode Using the Lattice Boltzmann Method

2006 ◽  
Author(s):  
Kyle N. Grew ◽  
Abhijit S. Joshi ◽  
Aldo A. Peracchio ◽  
Wilson K. S. Chiu
Keyword(s):  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Electrochemical Reaction ◽  
Coupled Model ◽  
Transport Processes ◽  
Flux Boundary Conditions ◽  
Sofc Anode ◽  
Boltzmann Method ◽  
Electrochemical Model ◽  
And Diffusion

A coupled electrochemical reaction and diffusion model has been developed and verified for investigation of mass transport processes in Solid Oxide Fuel Cell (SOFC) anode triple-phase boundary (TPB) regions. The coupled model utilizes a two-dimensional (2D), multi-species Lattice Boltzmann Method (LBM) to model the diffusion process. The electrochemical model is coupled through localized flux boundary conditions and is a function of applied activation overpotential and the localized hydrogen and water mole fractions. This model is designed so that the effects of the anode microstructure within TPB regions can be examined in detail. Results are provided for the independent validation of the electrochemical and diffusion sub-models, as well as for the coupled model. An analysis on a single closed pore is completed and validated with a Fick's law solution. A competition between the electrochemical reaction rate and the rate of mass transfer is observed to be dependent on inlet hydrogen mole fraction. The developed model is presented such that future studies on SOFC anode microstructures can be completed.

DNS of Drag-Reducing Turbulent Channel Flow With Coexisting Newtonian and Non-Newtonian Fluid

2005 ◽  
Vol 127 (5) ◽  
pp. 929-935 ◽  
Author(s):  
Bo Yu ◽  
Yasuo Kawaguchi
Keyword(s):  
Shear Stress ◽  
Reynolds Shear Stress ◽  
Flow Region ◽  
Turbulent Channel Flow ◽  
Turbulent Convection ◽  
Turbulent Channel Flows ◽  
Entire Flow ◽  
Shear Induced Structure ◽  
Induced Structure ◽  
And Diffusion

In the present study, we numerically investigated drag-reducing turbulent channel flows by surfactant additives. Surfactant additives were assumed to be uniformly distributed in the entire flow region by turbulent convection and diffusion, etc., but it was assumed that the shear-induced structure (SIS) (network of rod-like micelles) could form either in the region next to the walls or in the center region of the channel, making the fluid viscoelastic. In other regions surfactant additives were assumed to be incapable of building a network structure, and to exist in the form of molecules or micelles that do not affect the Newtonian properties of the fluid. With these assumptions, we studied the drag-reducing phenomenon with coexisting Newtonian and non-Newtonian fluids. From the study we identified the effectiveness of the network structures at different flow regions, and showed that the phenomenon of drag-reduction (DR) by surfactant additives is not only closely associated with the reduction of Reynolds shear stress but also related to the induced viscoelastic shear stress.

Dissolved Oxygen Convection and Diffusion Numerical Simulation of Water and Air Mixture Flow in Circular Pipe

2011 ◽  
Vol 383-390 ◽  
pp. 6651-6656
Author(s):  
Ze Gao Yin ◽  
Xian Wei Cao ◽  
Dong Sheng Cheng ◽  
Le Wang
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
Dissolved Oxygen ◽  
Oxygen Concentration ◽  
Pipe Flow ◽  
Concentration Distribution ◽  
Dissolved Oxygen Concentration ◽  
Mixture Flow ◽  
Velocity Pressure ◽  
And Diffusion

In Fluent, the 3-D RNG k–ε mathematical model is employed to compute water and air mixture pipe flow. The dissolved oxygen convectionaεnd diffusion model is established to simulate the concentration distribution of dissolved oxygen with user defined scalar method. Velocity, pressure and dissolved oxygen concentration are computed. Then, dissolved oxygen concentration and pressure are compared with the data of physical model, and they agree with each other approximately, showing it is valid and reliable to compute the mixture pipe flow and dissolved oxygen concentration with the model .Furthermore, under a specific condition, velocity, pressure and dissolved oxygen concentration of water and air mixture pipe flow are computed and their characteristics are analyzed.

Numerical Simulation of Diffusion of UDMH in Confined Space

2013 ◽  
Vol 295-298 ◽  
pp. 586-589
Author(s):  
Jia Zhao Chen ◽  
Chao Ning ◽  
Yu Xiang Zhang
Keyword(s):  
Numerical Simulation ◽  
Concentration Distribution ◽  
Geometric Model ◽  
Polluted Area ◽  
Confined Space ◽  
Gas Concentration ◽  
Diffusion Pattern ◽  
Toxic Gas ◽  
3D Geometric Model ◽  
And Diffusion

In order to study the diffusion pattern of Unsymmetrical Dimethyl Hydrazine (UDMH) in a confined space, a 3D geometric model of cylindrical space with a column obstacle in the center was built and diffusion of UDMH in the space was simulated by using FLUENT. The gas concentration distribution in the space was gained at different moments, and the polluted area with concentration above 0.5ppm was focused on. The simulation result suggests that the toxic gas is mainly concentrated in an area about 1m above the bottom of the space, and ventilation can effectively reduce the hazard time and continuous expansion of polluted area.

Experiment Research on Air Flow Rate Measurement Using Tracer Gas Method

2011 ◽  
Vol 374-377 ◽  
pp. 520-523
Author(s):  
Xian Yang Zeng ◽  
Zuo He Chi ◽  
Ming Guang Zheng ◽  
Gong Gang Sun ◽  
Guang Xue Zhang ◽  
...  
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Internal Diameter ◽  
Sampling Point ◽  
Air Flow Rate ◽  
Gas Flow Rate ◽  
Flow Rate Measurement ◽  
Tracer Gas ◽  
Injection Point ◽  
Relative Errors

Experiment research on the air flow rate measurement using tracer gas method in a 300mm internal diameter and 90° elbow duct are presented, which CO and air are selected as tracer gas and gas stream. Results show that the relative errors between the flow rate measured by tracer gas method and turbine flowmeter are varied in the range of -2.15%~1.69% when the injection point is upstream of the elbow on 7D~13D (D is the internal diameter of the duct), and the sampling point is downstream of the elbow on 10D~14D. The further distances of the injection point and sampling point are apart, the less relative errors of the gas flow rate measured by tracer gas method and turbine flowmeter are made. The injection flow rate of tracer gas should be matched with the gas flow rate in the duct. It is a simple and effective method that gas flowmeter online calibration with tracer gas method on the large diameter industrial gas pipeline transportation.

EXPONENTIAL TRANSFER AND DIFFUSION

1960 ◽  
Vol 38 (11) ◽  
pp. 1406-1427 ◽  
Author(s):  
W. Rabinovitch
Keyword(s):  
Diffusion Equation ◽  
Concentration Distribution ◽  
Numerical Evaluation ◽  
Reaction Products ◽  
One Dimensional ◽  
First Order ◽  
Irreversible Chemical Reaction ◽  
Probability Integral ◽  
The One ◽  
And Diffusion

The one-dimensional heat equation is solved for exponentially decaying rate of increment and decrement of temperature at the surface of a semi-infinite medium.The diffusion equation is solved for exponentially decaying rate of transfer from a source to a diffusion medium. The two types of sources are: mass initially (a) located at a point, and (b) distributed at interfaces within a porous rectangular parallelepiped or sphere. Solutions for subsequent concentration distribution are stated, and compared with the well-known cases of instantaneous transfer. Numerical evaluation is afforded by the probability integral of complex argument. The treatment is applicable to cases of first-order irreversible chemical reaction and simultaneous diffusion of reaction products.

scholarly journals Recovery of the first ever multi-year lidar dataset of the stratospheric aerosol layer, from Lexington, MA, and Fairbanks, AK, January 1964 to July 1965

2021 ◽  
Vol 13 (9) ◽  
pp. 4407-4423
Author(s):  
Juan-Carlos Antuña-Marrero ◽  
Graham W. Mann ◽  
John Barnes ◽  
Albeht Rodríguez-Vega ◽  
Sarah Shallcross ◽  
...  
Keyword(s):  
Aerosol Optical Depth ◽  
Optical Depth ◽  
Coupled Model ◽  
Stratospheric Aerosol ◽  
Aerosol Layer ◽  
Large Variability ◽  
Aerosol Model ◽  
Intercomparison Project ◽  
Relative Errors ◽  
The Tropics

Abstract. We report the recovery and processing methodology of the first ever multi-year lidar dataset of the stratospheric aerosol layer. A Q-switched ruby lidar measured 66 vertical profiles of 694 nm attenuated backscatter at Lexington, Massachusetts, between January 1964 and August 1965, with an additional nine profile measurements conducted from College, Alaska, during July and August 1964. We describe the processing of the recovered lidar backscattering ratio profiles to produce mid-visible (532 nm) stratospheric aerosol extinction profiles (sAEP532) and stratospheric aerosol optical depth (sAOD532) measurements, utilizing a number of contemporary measurements of several different atmospheric variables. Stratospheric soundings of temperature and pressure generate an accurate local molecular backscattering profile, with nearby ozone soundings determining the ozone absorption, which are used to correct for two-way ozone transmittance. Two-way aerosol transmittance corrections are also applied based on nearby observations of total aerosol optical depth (across the troposphere and stratosphere) from sun photometer measurements. We show that accounting for these two-way transmittance effects substantially increases the magnitude of the 1964/1965 stratospheric aerosol layer's optical thickness in the Northern Hemisphere mid-latitudes, then ∼ 50 % larger than represented in the Coupled Model Intercomparison Project 6 (CMIP6) volcanic forcing dataset. Compared to the uncorrected dataset, the combined transmittance correction increases the sAOD532 by up to 66 % for Lexington and up to 27 % for Fairbanks, as well as individual sAEP532 adjustments of similar magnitude. Comparisons with the few contemporary measurements available show better agreement with the corrected two-way transmittance values. Within the January 1964 to August 1965 measurement time span, the corrected Lexington sAOD532 time series is substantially above 0.05 in three distinct periods, October 1964, March 1965, and May–June 1965, whereas the 6 nights the lidar measured in December 1964 and January 1965 had sAOD values of at most ∼ 0.03. The comparison with interactive stratospheric aerosol model simulations of the Agung aerosol cloud shows that, although substantial variation in mid-latitude sAOD532 are expected from the seasonal cycle in the stratospheric circulation, the Agung cloud's dispersion from the tropics would have been at its strongest in winter and weakest in summer. The increasing trend in sAOD from January to July 1965, also considering the large variability, suggests that the observed variations are from a different source than Agung, possibly from one or both of the two eruptions that occurred in 1964/1965 with a Volcanic Explosivity Index (VEI) of 3: Trident, Alaska, and Vestmannaeyjar, Heimaey, south of Iceland. A detailed error analysis of the uncertainties in each of the variables involved in the processing chain was conducted. Relative errors for the uncorrected sAEP532 were 54 % for Fairbanks and 44 % Lexington. For the corrected sAEP532 the errors were 61 % and 64 %, respectively. The analysis of the uncertainties identified variables that with additional data recovery and reprocessing could reduce these relative error levels. Data described in this work are available at https://doi.org/10.1594/PANGAEA.922105 (Antuña-Marrero et al., 2020a).

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