This page has only limited features, please log in for full access.
In shallow geothermal systems natural and forced groundwater movement as well as the temperature driven flow plays an important role on the borehole heat exchanger efficiency.
The analysis of the efficiency of innovative heat exchangers installed in a fractured limestone aquifer was carried out through three-dimensional numerical simulations and experimental investigations on physical models.
The coastal fractured limestone aquifer of the industrial area of Bari (Italy) was chosen as benchmark field site in order to identify the aquifer parameter range and the respective combinations. The role of seawater intrusion on the borehole heat exchanger efficiency was deepen .
The results disclosed that the efficiency of the innovative heat exchangers is strictly dependent on the aquifer transmissivity and groundwater flow under natural and forced groundwater conditions.
Discussion on the performance of the seasonal heat storage and the occurrence of the thermal interference between the borehole heat exchanger was presented.
Nicola Pastore; Claudia Cherubini; Concetta Immacolata Giasi. Analysis of novel shallow geothermal system in coastal fractured limestone aquifer. 2021, 1 .
AMA StyleNicola Pastore, Claudia Cherubini, Concetta Immacolata Giasi. Analysis of novel shallow geothermal system in coastal fractured limestone aquifer. . 2021; ():1.
Chicago/Turabian StyleNicola Pastore; Claudia Cherubini; Concetta Immacolata Giasi. 2021. "Analysis of novel shallow geothermal system in coastal fractured limestone aquifer." , no. : 1.
In designing and sizing of borehole thermal energy system, natural groundwater movement and temperature driven flow have a great importance on the borehole heat exchanger efficiency. The efficiency of double U – tube arrangement in gravel – backfilled borehole installed in a fractured limestone aquifer has been analyzed by means of three – dimensional numerical simulations. The numerical model is representative of 1 m deep of gravel back – filled borehole surrounded by the fractured aquifer. Several simulations have been carried out in order to evaluate the effect of aquifer parameters and boundary conditions on heat exchange efficiency by varying the mean temperature within the double U - tube. The fractured limestone aquifer of the industrial area of Bari (Italy) has been chosen as field site in order to identify the aquifer parameter range and the respective combinations. The results highlight that borehole thermal energy system efficiency is strictly dependent on aquifer transmissivity and groundwater Darcian velocity. The conducted analysis shows that, under lower Darcian groundwater flow and lower aquifer transmissivity, heat transfer efficiency increases at least by 25% compared to stagnant water, whereas heat transfer in the aquifer is governed by heat conduction. The increase of aquifer transmissivity induces the thermosiphon effect enhancing heat transfer processes both in the gravel back-filled borehole and aquifer. At higher values of groundwater Darcian velocity (> 0.1 m/d) advection due to groundwater flow is not negligible and mixed with free convection enhancing heat transfer further. Based on the results, discussion on the performance and environmental constraint of gravel back – filled borehole at field site has been presented.
Nicola Pastore; Claudia Cherubini; Concetta I. Giasi. Analysis of gravel back-filled borehole heat exchanger in karst fractured limestone aquifer at local scale. Geothermics 2020, 89, 101971 .
AMA StyleNicola Pastore, Claudia Cherubini, Concetta I. Giasi. Analysis of gravel back-filled borehole heat exchanger in karst fractured limestone aquifer at local scale. Geothermics. 2020; 89 ():101971.
Chicago/Turabian StyleNicola Pastore; Claudia Cherubini; Concetta I. Giasi. 2020. "Analysis of gravel back-filled borehole heat exchanger in karst fractured limestone aquifer at local scale." Geothermics 89, no. : 101971.
We analyzed the complex dynamics that are involved the groundwater level variations due to the episodic rainfall supply in the Ionian coastal plain surficial aquifer located in Southern Italy. In this aquifer, as a consequence of the particular hydrogeological framework, both direct and lateral recharge mechanisms coexist. Hence, the dynamics of groundwater level variations are quite complex and strongly non-linear. Our focus was essentially on the short-term behavior of groundwater levels, with a specific analysis on episodic rainfall events. To model these dynamics, due to the presence of the preferential pathways in the infiltration processes, a kinematic dispersion wave model was used. Specifically, a one-dimensional and non-linear particle-based numerical model was developed. It uses ideal particles with constant water volume travel, according to celerity and hydraulic dispersion, to simulate the infiltration rate wave through the vadose zone. The infiltration rate that reaches the water table represents the input function to evaluate the aquifer groundwater level fluctuations. As a consequence of the special lithological and storage capacity characteristics of the surficial layers, groundwater flow conditions change from unconfined to confined. The developed model analyzes the direct groundwater supply under natural conditions, including episodic rainfall, and it has been validated using a high-resolution time series of rainfall data and groundwater level obtained from the monitoring station Terra Montonata.
Nicola Pastore; Claudia Cherubini; Angelo Doglioni; Concetta Immacolata Giasi; Vincenzo Simeone. Modelling of the Complex Groundwater Level Dynamics during Episodic Rainfall Events of a Surficial Aquifer in Southern Italy. Water 2020, 12, 2916 .
AMA StyleNicola Pastore, Claudia Cherubini, Angelo Doglioni, Concetta Immacolata Giasi, Vincenzo Simeone. Modelling of the Complex Groundwater Level Dynamics during Episodic Rainfall Events of a Surficial Aquifer in Southern Italy. Water. 2020; 12 (10):2916.
Chicago/Turabian StyleNicola Pastore; Claudia Cherubini; Angelo Doglioni; Concetta Immacolata Giasi; Vincenzo Simeone. 2020. "Modelling of the Complex Groundwater Level Dynamics during Episodic Rainfall Events of a Surficial Aquifer in Southern Italy." Water 12, no. 10: 2916.
Characterizing the transport and degradation of chlorinated ethenes in fractured aquifers, as well as the assessment of cleanup times, poses an extreme technical challenge. In the presented study, a method to analyze reactive transport and reductive dechlorination of chlorinated solvents in fractured aquifers is developed. A rough-walled parallel-plate model of nonlinear flow behavior is coupled with random-walk particle tracking, incorporating particle exchange between the mobile and stagnant zones, adsorption processes, and reductive dechlorination reaction pathways. The developed methodology, considering reductive dechlorination processes in a Lagrangian framework, is able to simulate the motion of particles affected by first-order network reactions, so that particles move according to their chemical state, affecting physical transport processes (advection, dispersion, mass-transfer exchange between mobile and stagnant zones). The developed model is applied to a case study of groundwater contamination in the industrial area of Bari and Modugno (Italy), where the limestone aquifer has a fractured, karstic nature. The steady-state distribution of the contamination by chlorinated ethenes from a source at a hot spot is obtained and compared with the observed scenario of contamination, in order to estimate the plausible transport and degradation processes and the mass loading at source. The study represents a valuable tool in deciding the role of natural attenuation as a treatment option, where the natural attenuation capacity of groundwater can be integrated with engineering methods in order to obtain site remediation.
Nicola Pastore; Claudia Cherubini; Concetta I. Giasi; Dimitra Rapti. Numerical model of the behavior of chlorinated ethenes in a fractured, karstic limestone aquifer. Hydrogeology Journal 2020, 29, 667 -686.
AMA StyleNicola Pastore, Claudia Cherubini, Concetta I. Giasi, Dimitra Rapti. Numerical model of the behavior of chlorinated ethenes in a fractured, karstic limestone aquifer. Hydrogeology Journal. 2020; 29 (2):667-686.
Chicago/Turabian StyleNicola Pastore; Claudia Cherubini; Concetta I. Giasi; Dimitra Rapti. 2020. "Numerical model of the behavior of chlorinated ethenes in a fractured, karstic limestone aquifer." Hydrogeology Journal 29, no. 2: 667-686.
The paper presents a modeling framework to analyze the effect of episodic rainfall supply on groundwater dynamics in the Ionian coastal plain multilayered aquifer. The focus is essentially on the short-term behavior of the shallowest layer, with a specific analysis on episodic rainfall events. In the studied aquifer, groundwater level responds sensitively to rainfall events, highlighting the presence of preferential recharge zones. The hydraulic head peak is a function of groundwater level antecedent to the rainfall event. A kinematic dispersion wave model was used to model infiltration processes via preferential pathways. A one-dimensional and non-linear particle based numerical model was developed. Particles with constant water volume travel according to celerity and hydraulic dispersion to simulate the infiltration rate wave through the vadose zone. The flow rate that reaches the water table represents the input function to determine groundwater level fluctuations along groundwater flow direction and according to the lithological features of the surficial levels of the multilayered aquifer, its storage capacity changes passing from unconfined to confined conditions. The model was validated with high time resolution time series of precipitation and groundwater level coming from Terra Montonata meteo-climatic and groundwater level monitoring station. The developed model represents a basis for evaluating and predicting groundwater discharge of the shallowest layers of the Ionian coastal multilayered aquifer under natural conditions including episodic rainfall.
Nicola Pastore; Claudia Cherubini; Angelo Doglioni; Concetta I. Giasi; Vincenzo Simeone. A Novel Approach to Model the Hydrodynamic Response of the Surficial Level of the Ionian Multilayered Aquifer during Episodic Rainfall Events. 2020, 1 .
AMA StyleNicola Pastore, Claudia Cherubini, Angelo Doglioni, Concetta I. Giasi, Vincenzo Simeone. A Novel Approach to Model the Hydrodynamic Response of the Surficial Level of the Ionian Multilayered Aquifer during Episodic Rainfall Events. . 2020; ():1.
Chicago/Turabian StyleNicola Pastore; Claudia Cherubini; Angelo Doglioni; Concetta I. Giasi; Vincenzo Simeone. 2020. "A Novel Approach to Model the Hydrodynamic Response of the Surficial Level of the Ionian Multilayered Aquifer during Episodic Rainfall Events." , no. : 1.
Modeling fluid flow and solute transport dynamics in fractured karst aquifers is one of the most challenging tasks in hydrogeology. The present study investigates the hotspots of groundwater contamination in the industrial area of Modugno (Bari – southern Italy), where the limestone aquifer has a fractured and karstic nature. A rough walled parallel plate model coupled with a geostatistical analysis to infer the values of the equivalent aperture has been implemented and calibrated on the basis of piezometric data. Using the random walk theory, the steady-state distribution of hypothetical contamination with the source at the hotspot has been carried out, reproducing a pollution scenario which is compatible with the observed one. From an analysis of the flow and transport pattern it is possible to infer that the anticline affecting the Calcare di Bari formation in direction ENE–WSW influences the direction of flow as well as the propagation of the contaminant. The results also show that the presence of nonlinear flow influences advection, in that it leads to a delay in solute transport with respect to the linear flow assumption. This is due to the non-constant distribution of solutes according to different pathways for fractured media which is related to the flow rate.
Claudia Cherubini; Nicola Pastore; Dimitra Rapti; Concetta I. Giasi. Numerical modeling of flow and transport in the Bari industrial area by means of rough walled parallel plate and random walk models. Hydrology and Earth System Sciences 2018, 22, 5211 -5225.
AMA StyleClaudia Cherubini, Nicola Pastore, Dimitra Rapti, Concetta I. Giasi. Numerical modeling of flow and transport in the Bari industrial area by means of rough walled parallel plate and random walk models. Hydrology and Earth System Sciences. 2018; 22 (10):5211-5225.
Chicago/Turabian StyleClaudia Cherubini; Nicola Pastore; Dimitra Rapti; Concetta I. Giasi. 2018. "Numerical modeling of flow and transport in the Bari industrial area by means of rough walled parallel plate and random walk models." Hydrology and Earth System Sciences 22, no. 10: 5211-5225.
Nicola Pastore. Fluid Flow, Mass, and Heat Transport Laboratory Experiments in Artificially Fractured Rock. Hydrology of Artificial and Controlled Experiments 2018, 1 .
AMA StyleNicola Pastore. Fluid Flow, Mass, and Heat Transport Laboratory Experiments in Artificially Fractured Rock. Hydrology of Artificial and Controlled Experiments. 2018; ():1.
Chicago/Turabian StyleNicola Pastore. 2018. "Fluid Flow, Mass, and Heat Transport Laboratory Experiments in Artificially Fractured Rock." Hydrology of Artificial and Controlled Experiments , no. : 1.
The present study is aimed at extending this thematic issue through heat transport experiments and their interpretation at laboratory scale. An experimental study to evaluate the dynamics of forced convection heat transfer in a thermally isolated column filled with porous medium has been carried out. The behavior of two porous media with different grain sizes and specific surfaces has been observed. The experimental data have been compared with an analytical solution for one-dimensional heat transport for local nonthermal equilibrium condition. The interpretation of the experimental data shows that the heterogeneity of the porous medium affects heat transport dynamics, causing a channeling effect which has consequences on thermal dispersion phenomena and heat transfer between fluid and solid phases, limiting the capacity to store or dissipate heat in the porous medium.
Nicola Pastore; Claudia Cherubini; Dimitra Rapti; Concetta I. Giasi. Experimental study of forced convection heat transport in porous media. Nonlinear Processes in Geophysics 2018, 25, 279 -290.
AMA StyleNicola Pastore, Claudia Cherubini, Dimitra Rapti, Concetta I. Giasi. Experimental study of forced convection heat transport in porous media. Nonlinear Processes in Geophysics. 2018; 25 (2):279-290.
Chicago/Turabian StyleNicola Pastore; Claudia Cherubini; Dimitra Rapti; Concetta I. Giasi. 2018. "Experimental study of forced convection heat transport in porous media." Nonlinear Processes in Geophysics 25, no. 2: 279-290.
Modelling fluid flow and solute transport dynamics in fractured karst aquifers is one of the most challenging tasks in hydrogeology. The present study investigates on the hotspots of groundwater contamination in the industrial area of Modugno (Bari – Southern Italy) where the limestone aquifer has a fractured and karstic nature. A rough walled parallel plate model coupled with a geostatistical analysis to infer the values of the equivalent aperture has been implemented and calibrated on the basis of piezometric data. Using the random walk theory, the steady state distribution of hypothetical contamination with the source at the hot spot has been carried out reproducing a pollution scenario which is compatible with the observed one. From an analysis of the flow and transport pattern it is possible to infer that the anticline affecting the Calcare di Bari formation in directions ENE-WSW influences the direction of flow as well as the propagation of the contaminant. The results also show that the presence of nonlinear flow influences advection, in that it leads to a delay in solute transport respect to the linear flow assumption. This is due to the not constant distribution of solute according to different pathways for fractured media which is related to the flow rate.
Claudia Cherubini; Nicola Pastore; Dimitra Rapti; Concetta I. Giasi. Numerical modelling of flow and transport in Bari industrial area by means of rough walled parallel plate and random walk models. 2018, 2018, 1 -32.
AMA StyleClaudia Cherubini, Nicola Pastore, Dimitra Rapti, Concetta I. Giasi. Numerical modelling of flow and transport in Bari industrial area by means of rough walled parallel plate and random walk models. . 2018; 2018 ():1-32.
Chicago/Turabian StyleClaudia Cherubini; Nicola Pastore; Dimitra Rapti; Concetta I. Giasi. 2018. "Numerical modelling of flow and transport in Bari industrial area by means of rough walled parallel plate and random walk models." 2018, no. : 1-32.
In this study, laboratory experiments and simulations have been conducted to investigate single water phase flow through self-affine rough fractures. It is the first time that 3D printing technology is proposed for the application of generating self-affine rough fractures. The experimental setup was designed to measure the water volume by dividing the discharging surface into five sections with equal distances under constant injection flow rates. Water flow through self-affine rough fractures was simulated numerically by using the Lattice Boltzmann method (LBM). An agreement between the experimental data and the numerical simulation results was achieved. The fractal dimension is positively correlated to fracture surface roughness and the fracture inclination represents the gravity force acting on the water flow. The influences of fracture inclinations, fractal dimensions, and mismatch wavelengths were studied and analyzed, with an emphasis on flow paths through a self-affine rough fracture. Different values of fractal dimensions, fracture inclinations, and mismatch wavelengths result in small changes of flow rates from five sections of discharging surface. However, the section of discharging surface with the largest flow rate remains constant. In addition, it is found that the gravity force can affect flow paths. Combined with the experimental data, the simulation results are used to explain the preferential flow paths through fracture rough surfaces from a new perspective. The results may enhance our understanding of fluid flow through fractures and provide a solid background for further research in the areas of energy exploration and production.
Jiawei Li; Claudia Cherubini; Sergio Andres Galindo Torres; Zi Li; Nicola Pastore; Ling Li. Laboratory Investigation of Flow Paths in 3D Self-Affine Fractures with Lattice Boltzmann Simulations. Energies 2018, 11, 168 .
AMA StyleJiawei Li, Claudia Cherubini, Sergio Andres Galindo Torres, Zi Li, Nicola Pastore, Ling Li. Laboratory Investigation of Flow Paths in 3D Self-Affine Fractures with Lattice Boltzmann Simulations. Energies. 2018; 11 (1):168.
Chicago/Turabian StyleJiawei Li; Claudia Cherubini; Sergio Andres Galindo Torres; Zi Li; Nicola Pastore; Ling Li. 2018. "Laboratory Investigation of Flow Paths in 3D Self-Affine Fractures with Lattice Boltzmann Simulations." Energies 11, no. 1: 168.
Nicola Pastore; C. Cherubini; C.I. Giasi; J.M. Redondo. Experimental investigation of heat transport through single synthetic fractures. Energy Procedia 2017, 125, 327 -334.
AMA StyleNicola Pastore, C. Cherubini, C.I. Giasi, J.M. Redondo. Experimental investigation of heat transport through single synthetic fractures. Energy Procedia. 2017; 125 ():327-334.
Chicago/Turabian StyleNicola Pastore; C. Cherubini; C.I. Giasi; J.M. Redondo. 2017. "Experimental investigation of heat transport through single synthetic fractures." Energy Procedia 125, no. : 327-334.
When dealing with groundwater resources, a better knowledge of the hydrological processes governing flow in the unsaturated zone would improve the assessment of the natural aquifer recharge and its vulnerability to contamination. In North West Europe groundwater from unconfined chalk aquifers constitutes a major water resource, therefore the need for a good hydrological understanding of the chalk unsaturated zone is essential, as it is the main control for aquifer recharge. In the North Paris Basin, much of the recharge must pass through a regional chalk bed that is composed of a porous matrix with embedded fractures. The case study regards the role of the thick unsaturated zone of the Cretaceous chalk aquifer in Picardy (North of France) that controls the hydraulic response to rainfall. In order to describe the flow rate that reaches the water table, the kinematic diffusion theory has been applied that treats the unsaturated water flow equation as a wave equation composed of diffusive and gravitational components. The kinematic diffusion model has proved to be a convenient method to study groundwater recharge processes in that it was able to provide a satisfactory fitting both for rising and falling periods of water table fluctuation. It has also proved to give an answer to the question whether unsaturated flow can be described using the theory of kinematic waves. The answer to the question depends principally on the status of soil moisture. For higher values of hydraulic Peclet number (increasing saturation), the pressure wave velocities dominate and the preferential flow paths is provided by the shallow fractures in the vadose zone. With decreasing values of hydraulic Peclet number (increasing water tension), rapid wave velocities are mostly due to the diffusion of the flow wave. Diffusive phenomena are provided by matrix and fracture-matrix interaction. The use of a kinematic wave in this context constitutes a good simplified approach especially in cases when there is a lack of information concerning the hydraulic properties of the fractures/macropores close to saturation.
Nicola Pastore; Claudia Cherubini; Concetta I. Giasi. Kinematic diffusion approach to describe recharge phenomena in unsaturated fractured chalk. Journal of Hydrology and Hydromechanics 2017, 65, 287 -296.
AMA StyleNicola Pastore, Claudia Cherubini, Concetta I. Giasi. Kinematic diffusion approach to describe recharge phenomena in unsaturated fractured chalk. Journal of Hydrology and Hydromechanics. 2017; 65 (3):287-296.
Chicago/Turabian StyleNicola Pastore; Claudia Cherubini; Concetta I. Giasi. 2017. "Kinematic diffusion approach to describe recharge phenomena in unsaturated fractured chalk." Journal of Hydrology and Hydromechanics 65, no. 3: 287-296.
Low enthalpy geothermal energy is a renewable resource that is still underexploited nowadays in relation to its potential for development in society worldwide. Most of its applications have already been investigated, such as heating and cooling of private and public buildings, road defrosting, cooling of industrial processes, food drying systems or desalination. Geothermal power development is a long, risky and expensive process. It basically consists of successive development stages aimed at locating the resources (exploration), confirming the power generating capacity of the reservoir (confirmation) and building the power plant and associated structures (site development). Different factors intervene in influencing the length, difficulty and materials required for these phases, thereby affecting their cost. One of the major limitations related to the installation of low enthalpy geothermal power plants regards the initial development steps that are risky and the upfront capital costs that are huge. Most of the total cost of geothermal power is related to the reimbursement of invested capital and associated returns. In order to increase the optimal efficiency of installations which use groundwater as a geothermal resource, flow and heat transport dynamics in aquifers need to be well characterized. Especially in fractured rock aquifers these processes represent critical elements that are not well known. Therefore there is a tendency to oversize geothermal plants. In the literature there are very few studies on heat transport, especially on fractured media. This study is aimed at deepening the understanding of this topic through heat transport experiments in fractured networks and their interpretation. Heat transfer tests have been carried out on the experimental apparatus previously employed to perform flow and tracer transport experiments, which has been modified in order to analyze heat transport dynamics in a network of fractures. In order to model the obtained thermal breakthrough curves, the Explicit Network Model (ENM) has been used, which is based on an adaptation of Tang's solution for the transport of the solutes in a semi-infinite single fracture embedded in a porous matrix. Parameter estimation, time moment analysis, tailing character and other dimensionless parameters have permitted a better understanding of the dynamics of heat transport and the efficiency of heat exchange between the fractures and the matrix. The results have been compared with the previous experimental studies on solute transport.
Claudia Cherubini; Nicola Pastore; Concetta I. Giasi; Nicoletta Maria Allegretti. Laboratory experimental investigation of heat transport in fractured media. Nonlinear Processes in Geophysics 2017, 24, 23 -42.
AMA StyleClaudia Cherubini, Nicola Pastore, Concetta I. Giasi, Nicoletta Maria Allegretti. Laboratory experimental investigation of heat transport in fractured media. Nonlinear Processes in Geophysics. 2017; 24 (1):23-42.
Chicago/Turabian StyleClaudia Cherubini; Nicola Pastore; Concetta I. Giasi; Nicoletta Maria Allegretti. 2017. "Laboratory experimental investigation of heat transport in fractured media." Nonlinear Processes in Geophysics 24, no. 1: 23-42.
Romain Armand; Claudia Cherubini; Johann Tuduri; Nicola Pastore; Olivier Pourret. Corrigendum to “Rare earth elements in French stream waters – revisiting 'the geochemical continental cycle using FOREGS dataset” [J. Geochem. Explor. 157 (2015) 132–142]. Journal of Geochemical Exploration 2016, 170, 167 .
AMA StyleRomain Armand, Claudia Cherubini, Johann Tuduri, Nicola Pastore, Olivier Pourret. Corrigendum to “Rare earth elements in French stream waters – revisiting 'the geochemical continental cycle using FOREGS dataset” [J. Geochem. Explor. 157 (2015) 132–142]. Journal of Geochemical Exploration. 2016; 170 ():167.
Chicago/Turabian StyleRomain Armand; Claudia Cherubini; Johann Tuduri; Nicola Pastore; Olivier Pourret. 2016. "Corrigendum to “Rare earth elements in French stream waters – revisiting 'the geochemical continental cycle using FOREGS dataset” [J. Geochem. Explor. 157 (2015) 132–142]." Journal of Geochemical Exploration 170, no. : 167.
The present study involves the experimental investigation of heat transport due to the forced convective flow through a thermally isolated porous medium column.The experiments regard the observation of thermal breakthrough curves obtained through a hot flow injection in correspondence of two thermocouples positioned along a thermally isolated column of porous medium. The experiment has been carried out for three flow rates in order to investigate the critical issues regarding heat transport phenomena such as the relationship between the thermal dispersion with the flow velocity and the validity of the local thermal equilibrium assumption between the fluid and solid phase
Nicola Pastore; C. Cherubini; C.I. Giasi; N.M. Allegretti. Experimental Investigations of Heat Transport Dynamics in a 1d Porous Medium Column. Energy Procedia 2016, 97, 233 -239.
AMA StyleNicola Pastore, C. Cherubini, C.I. Giasi, N.M. Allegretti. Experimental Investigations of Heat Transport Dynamics in a 1d Porous Medium Column. Energy Procedia. 2016; 97 ():233-239.
Chicago/Turabian StyleNicola Pastore; C. Cherubini; C.I. Giasi; N.M. Allegretti. 2016. "Experimental Investigations of Heat Transport Dynamics in a 1d Porous Medium Column." Energy Procedia 97, no. : 233-239.
Romain Armand; Claudia Cherubini; Johann Tuduri; Nicola Pastore; Olivier Pourret. Rare earth elements in French stream waters — Revisiting the geochemical continental cycle using FOREGS dataset. Journal of Geochemical Exploration 2015, 157, 132 -142.
AMA StyleRomain Armand, Claudia Cherubini, Johann Tuduri, Nicola Pastore, Olivier Pourret. Rare earth elements in French stream waters — Revisiting the geochemical continental cycle using FOREGS dataset. Journal of Geochemical Exploration. 2015; 157 ():132-142.
Chicago/Turabian StyleRomain Armand; Claudia Cherubini; Johann Tuduri; Nicola Pastore; Olivier Pourret. 2015. "Rare earth elements in French stream waters — Revisiting the geochemical continental cycle using FOREGS dataset." Journal of Geochemical Exploration 157, no. : 132-142.
Fractured rocks play an important role in transport of natural resources through subsurface systems. In recent years, interest has\ud grown in investigating heat transport by means of tracer tests, driven by the important current development of geothermal\ud applications. Many field and laboratory tracer tests in fractured media show that fracture - matrix exchange is more significant\ud for heat than mass tracers, thus thermal breakthrough curves are strongly controlled by matrix thermal diffusivity. In this study,\ud the behaviour of heat transport in a fractured network, at bench laboratory scale, has been investigated.Peer ReviewedPostprint (published version
N. Pastore; C Cherubini; C.I. Giasi; N.M. Allegretti; J.M. Redondo; M. Tarquis. Experimental Study of Heat Transport in Fractured Network. Energy Procedia 2015, 76, 273 -281.
AMA StyleN. Pastore, C Cherubini, C.I. Giasi, N.M. Allegretti, J.M. Redondo, M. Tarquis. Experimental Study of Heat Transport in Fractured Network. Energy Procedia. 2015; 76 ():273-281.
Chicago/Turabian StyleN. Pastore; C Cherubini; C.I. Giasi; N.M. Allegretti; J.M. Redondo; M. Tarquis. 2015. "Experimental Study of Heat Transport in Fractured Network." Energy Procedia 76, no. : 273-281.
In hydrogeology, the application of reliable tracer transport model approaches is a key issue to derive the hydrodynamic properties of aquifers. Laboratory- and field-scale tracer dispersion breakthrough curves (BTC) in fractured media are notorious for exhibiting early time arrivals and late time tailing that are not captured by the classical advection–dispersion equation (ADE). These "non-Fickian" features are proven to be better explained by a mobile–immobile (MIM) approach. In this conceptualization the fractured rock system is schematized as a continuous medium in which the liquid phase is separated into flowing and stagnant regions. The present study compares the performances and reliabilities of the classical MIM and the explicit network model (ENM), taking expressly into account the network geometry for describing tracer transport behavior in a fractured sample at bench scale. Though ENM shows better fitting results than MIM, the latter remains still valid as it proves to describe the observed curves quite well. The results show that the presence of nonlinear flow plays an important role in the behavior of solute transport. First, the distribution of solute according to different pathways is not constant, but it is related to the flow rate. Second, nonlinear flow influences advection in that it leads to a delay in solute transport respect to the linear flow assumption. However, nonlinear flow is not shown to be related with dispersion. The experimental results show that in the study case the geometrical dispersion dominates the Taylor dispersion. However, the interpretation with the ENM shows a weak transitional regime from geometrical dispersion to Taylor dispersion for high flow rates. Incorporating the description of the flow paths in the analytical modeling has proven to better fit the curves and to give a more robust interpretation of the solute transport.
C. Cherubini; C. I. Giasi; Nicola Pastore. On the reliability of analytical models to predict solute transport in a fracture network. Hydrology and Earth System Sciences 2014, 18, 2359 -2374.
AMA StyleC. Cherubini, C. I. Giasi, Nicola Pastore. On the reliability of analytical models to predict solute transport in a fracture network. Hydrology and Earth System Sciences. 2014; 18 (6):2359-2374.
Chicago/Turabian StyleC. Cherubini; C. I. Giasi; Nicola Pastore. 2014. "On the reliability of analytical models to predict solute transport in a fracture network." Hydrology and Earth System Sciences 18, no. 6: 2359-2374.
During a risk assessment procedure as well as when dealing with cleanup and monitoring strategies, accurate predictions of solute propagation in fractured rocks are of particular importance when assessing exposure pathways through which contaminants reach receptors. Experimental data obtained under controlled conditions such as in a laboratory allow to increase the understanding of the fundamental physics of fluid flow and solute transport in fractures. In this study, laboratory hydraulic and tracer tests have been carried out on an artificially created fractured rock sample. The tests regard the analysis of the hydraulic loss and the measurement of breakthrough curves for saline tracer pulse inside a rock sample of parallelepiped shape (0.60 × 0.40 × 0.08 m). The convolution theory has been applied in order to remove the effect of the acquisition apparatus on tracer experiments. The experimental results have shown evidence of a non-Darcy relationship between flow rate and hydraulic loss that is best described by Forchheimer's law. Furthermore, in the flow experiments both inertial and viscous flow terms are not negligible. The observed experimental breakthrough curves of solute transport have been modeled by the classical one-dimensional analytical solution for the advection–dispersion equation (ADE) and the single rate mobile–immobile model (MIM). The former model does not properly fit the first arrival and the tail while the latter, which recognizes the existence of mobile and immobile domains for transport, provides a very decent fit. The carried out experiments show that there exists a pronounced mobile–immobile zone interaction that cannot be neglected and that leads to a non-equilibrium behavior of solute transport. The existence of a non-Darcian flow regime has showed to influence the velocity field in that it gives rise to a delay in solute migration with respect to the predicted value assuming linear flow. Furthermore, the presence of inertial effects enhance non-equilibrium behavior. Instead, the presence of a transitional flow regime seems not to exert influence on the behavior of dispersion. The linear-type relationship found between velocity and dispersion demonstrates that for the range of imposed flow rates and for the selected path the geometrical dispersion dominates the mixing processes along the fracture network.
C. Cherubini; C. I. Giasi; N. Pastore. Evidence of non-Darcy flow and non-Fickian transport in fractured media at laboratory scale. Hydrology and Earth System Sciences 2013, 17, 2599 -2611.
AMA StyleC. Cherubini, C. I. Giasi, N. Pastore. Evidence of non-Darcy flow and non-Fickian transport in fractured media at laboratory scale. Hydrology and Earth System Sciences. 2013; 17 (7):2599-2611.
Chicago/Turabian StyleC. Cherubini; C. I. Giasi; N. Pastore. 2013. "Evidence of non-Darcy flow and non-Fickian transport in fractured media at laboratory scale." Hydrology and Earth System Sciences 17, no. 7: 2599-2611.
The knowledge of flow phenomena in fractured rocks is very important for groundwater resources management in hydrogeological engineering. A critical emerging issue for fractured aquifers is the validity of the Darcian-type "local cubic law", which assumes a linear relationship between flow rate and pressure gradient to accurately describe flow patterns. Experimental data obtained under controlled conditions such as in a laboratory increase our understanding of the fundamental physics of fracture flow and allow us to investigate the presence of non-linear flow inside fractures that generates a substantial deviation from Darcy's law. In this study the presence of non-linear flow in a fractured rock formation has been analyzed at bench scale in laboratory tests. The effects of non-linearity in flow have been investigated by analyzing hydraulic tests on an artificially created fractured rock sample of parallelepiped (0.60 × 0.40 × 0.8 m) shape. The volumes of water passing through different paths across the fractured sample for various hydraulic head differences have been measured, and the results of the experiments have been reported as specific flow rate vs. head gradient. The experimental results closely match the Forchheimer equation and describe a strong inertial regime. The results of the test have been interpreted by means of numerical simulations. For each pair of ports, several steady-state simulations have been carried out varying the hydraulic head difference between the inlet and outlet ports. The estimated linear and non-linear Forchheimer coefficients have been correlated to each other and respectively to the tortuosity of the flow paths. A correlation among the linear and non-linear Forchheimer coefficients is evident. Moreover, a tortuosity factor that influences flow dynamics has been determined.
C. Cherubini; C. I. Giasi; N. Pastore. Bench scale laboratory tests to analyze non-linear flow in fractured media. Hydrology and Earth System Sciences 2012, 16, 2511 -2522.
AMA StyleC. Cherubini, C. I. Giasi, N. Pastore. Bench scale laboratory tests to analyze non-linear flow in fractured media. Hydrology and Earth System Sciences. 2012; 16 (8):2511-2522.
Chicago/Turabian StyleC. Cherubini; C. I. Giasi; N. Pastore. 2012. "Bench scale laboratory tests to analyze non-linear flow in fractured media." Hydrology and Earth System Sciences 16, no. 8: 2511-2522.