Fluid travel time between a recharging and discharging well pair in an aquifer having a uniform regional flow field

1971 ◽  
Vol 14 (3-4) ◽  
pp. 362
Keyword(s):  
Flow Field ◽  
Travel Time ◽  
Regional Flow

scholarly journals Numerical Investigation on the Influence of Areal Flow on EGS Thermal Exploitation Based on the 3-D T-H Single Fracture Model

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 3026 ◽  
Author(s):  
Chi Yao ◽  
Yulong Shao ◽  
Jianhua Yang
Keyword(s):  
Flow Field ◽  
Three Dimensional ◽  
Fracture Model ◽  
Heat Extraction ◽  
Single Fracture ◽  
Production Well ◽  
Regional Flow ◽  
Well Spacing ◽  
Operating Lifetime ◽  
Recovery Performance

The research on the factors of heat recovery performance of Enhanced Geothermal Systems (EGS) is an important issue, especially in the well position optimization in EGS, because it can maximize the economic benefits of EGS. Based on the three-dimensional thermo and hydro (TH) single-fracture model, a flow field in the EGS is added to the model, the thermal energy mining of the EGS thermal reservoir is realized through the double well and better study of the impact of regional flow on EGS well placement. To verify the reliability of the three-dimensional numerical model, the comparison between the two-dimensional single fracture model and the single fracture analytical model is performed under the same conditions, and it is found that there is a good agreement between the numerical and the analytical solutions. The influence of the direction of regional flow on the thermal recovery performance of EGS is studied, and the operating lifetime, power generation and heat production rate of the system are used as the evaluation indicators. It is found that there are two stagnation points in the flow field under regional flow conditions, and the stagnation point position changes regularly with regional flow direction. The direction of regional flow has a great influence on the heat extraction ratio and service lifetime of the geothermal system, the layout of the double well must take into account the regional flow. When only considered the influence of regional flow on EGS, after 50 years of EGS operation, the production well temperature and system operating lifetime increase with the increase of β (the angle between the direction of the regional flow and the line connecting the centers of the two wells). When it has regional flow, the greater the well spacing, the greater the temperature of the production well, but when the well spacing increases to a certain value, the well spacing will not affect the temperature of the production well.

Flow field detection using acoustic travel time tomography

2007 ◽  
Vol 16 (4) ◽  
pp. 443-450 ◽  
Author(s):  
Manuela Barth ◽  
Armin Raabe ◽  
Klaus Arnold ◽  
Christian Resagk ◽  
Ronald du Puits
Keyword(s):  
Flow Field ◽  
Travel Time ◽  
Field Detection ◽  
Travel Time Tomography ◽  
Acoustic Travel Time

scholarly journals Crevasse patterns and the strain-rate tensor: a high-resolution comparison

1998 ◽  
Vol 44 (146) ◽  
pp. 68-76 ◽  
Author(s):  
J. T. Harper ◽  
N. F. Humphrey ◽  
W. T. Pfeffer
Keyword(s):  
Flow Field ◽  
Strain Rate ◽  
Longitudinal Strain ◽  
Principal Strain ◽  
Length Scale ◽  
Strain Rate Tensor ◽  
Regional Flow ◽  
Orthogonal Grid ◽  
Valley Glacier ◽  
Longitudinal Strain Rate

AbstractValues of the strain-rate tensor represented at a 20 m length scale are found to explain the pattern and orientation of crevasses in a 0.13 km2 reach of Worthington Glacier, Alaska, U.S.A. The flow field of the reach is constructed from surveyed displacements of 110 markers spaced 20-30 m apart. A velocity gradient method is then used to calculate values of the principal strain-rate axes at the nodes of a 20 m x 20 m orthogonal grid. Crevasses in the study reach are of two types, splaying and transverse, and are everywhere normal to the trajectories of greatest (most tensile) principal strain rate. Splaying crevasses exist where the longitudinal strain rate (x) is ≤ 0 and transverse crevasses are present under longitudinally extending flow (i.e. x > 0). The orientation of crevasses changes in the down-glacier direction, but the calculated rotation by the flow field does not account for this change in orientation. Observations suggest that individual crevasses represent local values of the regional flow field and are transient on the time-scale of 1-2 years; they are not persistent features that are translated and rotated by flow. Crevasse patterns are thus found to be a useful tool for mapping the strain-rate tensor in this reach of a temperate valley glacier.

scholarly journals Crevasse patterns and the strain-rate tensor: a high-resolution comparison

1998 ◽  
Vol 44 (146) ◽  
pp. 68-76 ◽  
Author(s):  
J. T. Harper ◽  
N. F. Humphrey ◽  
W. T. Pfeffer
Keyword(s):  
Flow Field ◽  
Strain Rate ◽  
Longitudinal Strain ◽  
Principal Strain ◽  
Length Scale ◽  
Strain Rate Tensor ◽  
Regional Flow ◽  
Orthogonal Grid ◽  
Valley Glacier ◽  
Longitudinal Strain Rate

AbstractValues of the strain-rate tensor represented at a 20 m length scale are found to explain the pattern and orientation of crevasses in a 0.13 km2reach of Worthington Glacier, Alaska, U.S.A. The flow field of the reach is constructed from surveyed displacements of 110 markers spaced 20-30 m apart. A velocity gradient method is then used to calculate values of the principal strain-rate axes at the nodes of a 20 m x 20 m orthogonal grid. Crevasses in the study reach are of two types, splaying and transverse, and are everywhere normal to the trajectories of greatest (most tensile) principal strain rate. Splaying crevasses exist where the longitudinal strain rate (x) is ≤ 0 and transverse crevasses are present under longitudinally extending flow (i.e.x> 0). The orientation of crevasses changes in the down-glacier direction, but the calculated rotation by the flow field does not account for this change in orientation. Observations suggest that individual crevasses represent local values of the regional flow field and are transient on the time-scale of 1-2 years; they are not persistent features that are translated and rotated by flow. Crevasse patterns are thus found to be a useful tool for mapping the strain-rate tensor in this reach of a temperate valley glacier.

scholarly journals Derivation of Geodesic Flow Fields and Spectrum in Digital Topographic Basins

2008 ◽  
Vol 2008 ◽  
pp. 1-26 ◽  
Author(s):  
Sin Liang Lim ◽  
B. S. Daya Sagar
Keyword(s):  
Flow Field ◽  
Travel Time ◽  
Geodesic Flow ◽  
Digital Elevation Models ◽  
Flow Fields ◽  
Basic Flow ◽  
Digital Form ◽  
Digital Elevation ◽  
Morphology Characterization

We present a framework to characterize terrestrial functions—surficial and bottom topographic regions that are represented, respectively, as raster digital elevation models (DEMs) and digital bathymetric models (DBMs)—through analysis of flow fields that are simulated via geodesic morphology. Characterization of such functions is done via a new descriptor. Computation of this new descriptor involves the following steps: (i) basin in digital form representing topographic fluctuations as an input, (ii) threshold decomposition of basin—that consists of channelized and nonchannelized regions—into sets, (iii) proper indexing of these sets to decide the marker set(s) and its (their) corresponding mask set(s), (iv) performing geodesic propagation that provides basic flow field structures, and (v) finally providing a new basin descriptor—geodesic spectrum. We demonstrated this five-step framework on five different synthetic and/or realistic DEMs and/or DBMs. This study provides potentially invaluable insights to further study the travel-time flood propagation within basins of both fluvial and tidal systems.

The role of hyporheic fluxes in regional groundwater modelling

2020 ◽  
Author(s):  
Brian Babak Mojarrad ◽  
Anders Wörman ◽  
Joakim Riml ◽  
Shulan Xu
Keyword(s):  
Flow Field ◽  
Groundwater Flow ◽  
Travel Time ◽  
Groundwater Modelling ◽  
Cumulative Distribution ◽  
Deep Groundwater ◽  
Scale Modelling ◽  
Groundwater Flow Field ◽  
Regional Groundwater

<p>The effect of hyporheic fluxes on deep groundwater flow field was investigated in a numerical modelling framework over a spectrum of spatial scales ranging from local bed forms to landscape structures in a Swedish boreal catchment. The groundwater modelling was conducted for the whole catchment in which the site-specific landscape morphology and geological heterogeneity were accounted for. Deep groundwater discharge was quantified through conducting particle tracing analysis for 10,000 inert particles (grid of 100 × 100) released from a flat horizontal surface located 500 meter below the minimum topographical elevation. Further, the streambed scale modelling was performed independently by applying an exact spectral solution to the hyporheic fluxes in streambeds based on fluctuations of the streambed topography. Monte Carlo simulations were used in the streambed scale modelling to cover uncertainties in hydrostatic and dynamic head contributions, as well as topographic fluctuations. Through superpositioning of the two model results, we found that the magnitude of deep groundwater vertical velocity at the stream-water interface was generally lower than the hyporheic exchange velocity at the streambed interface. Finally, the deep groundwater particles’ travel time and the fragmentation of groundwater upwelling zones used as the main metrics to evaluate the impact of hyporheic fluxes on deep groundwater flow field. The results showed that the regional groundwater travel time distribution near the streambed surface was influenced by hyporheic fluxes, an impact that was  substantial for the particles with longer travel times. The size of coherent groundwater upwelling zone at the streambed interface was also affected by hyporheic fluxes. Almost half the superimposed cases were found to be more fragmented due to the presence of hyporheic flow field, which shifted the cumulative distribution function for upwelling regions towards smaller areas. This study, highlights the role of hyporheic fluxes in groundwater modelling, which controls the streambed sediment ecosystem as well as fate and transport of contaminations between aquifer and streams.</p>

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