Pumping Zone Research Articles

Optimizing heat transfer with electro-osmotic ciliated propulsion in a non-uniform canals with Cu-blood characteristics considering thermal casson nano fluid

Electroosmosis peristaltic flows find promising applications in electro-fluid thrusters in space propulsion, polymer injection systems, ion exchange membrane designs, microbe fuel cells, biochip fabrication and fossil fuel energy process. In light of this, the current work aims to investigate blood based electroosmotic peristaltic flow in a ciliated, non-uniform propagation channel when copper nanoparticles are present. For that purpose, mathematical modeling is done in two dimensional frame and then governing partial differential equations are simplified and converted in ordinary differential equations using dimensionless quantities and long wave length and low Reynolds number approximations. In result we got coupled nonlinear boundary value problem that is solved numerically using three-stage Lobatto IIIa formula known as bvp4c invoking shooting technique. Peristaltic ciliated waves are thought to pass along the channel wall. The properties of both fluid phase and particle phase flow are modeled and investigated. Plotting against various parameters, streamline contours, temperature contours, concentration and temperature profiles, and pressure rise graphs are examined in-depth from a physical perspective. The obtained results revealed that concentration profile α upsurges for rising values of Casson fluid parameter β, nanoparticle volume fraction ϕ and flow rate Q while it drops with an increase in particulate volumetric fraction C, Eckert number Ec, Soret number Sr, Schmidt number Sc and viscosity constant. A decrease in temperature is also caused by an increase in the volumetric percentage of nanoparticles. In the pumping portion, there is a decrease in pressure rise; however, this decrease changes to an increase in the increased pumping zone.

The Influence of Pump-Turbine Specific Speed on Hydraulic Transient Processes

The main porpose of this paper is to perform and present at transient process analysis on the influence of different specific speeds (nq) of the three-model pump-turbines that may implemented at the hydropower pump storage plant (HPSP) Bajina Basta, Serbia. The intention is to analyze the operation regimes along the S-shaped characteristic curve, which creates difficulties in calculations during the load-rejection process. These problems are manifested by an unusual increase in water pressure, followed by an increase in machine vibrations, thus threatening the stability of machine operation. The subject of this research is the four-quadrant (4Q) characteristic curves, presented in the form of Suter curves (the head and momentum parameters (Wh and Wm), in dependence of angle (θ)) for different wicket gate openings, of the three pump-turbine models with different specific speeds (nq = 27, nq = 38 and nq = 50). These 4Q characteristics are used as input data for numerical code developed to calculate the simultaneous load rejection of both pump-turbines. The numerical code is based on the method of characteristics and applied to the test case at HPSP. This is especially relevant when dealing with characteristic S-shaped curves that may lead to serious instability in operation during the transient process. The calculation results show changes in the pressure, speed of rotation and discharge of the machine operation regimes, but the important findings are reflected in further application of the results to determine the parametric flow and speed (Q11 and n11) trajectories of the operating points, where the unstable behavior of a pump-turbine operating in turbine mode is presented and periodically the trajectories also pass through the reverse pump zone.

Cover collapse sinkhole formation is delayed in time and uncorrelated to distance from quarry in a long-term study of a karst basin

Collapse sinkholes are problematic for the hazards they bring to property, infrastructure, and human life but the prediction of their formation in time and space remains elusive. We make use of long-term data gathered in a small, highly monitored, hydrologically constrained basin; Primrose Creek, Bucks County, Pennsylvania, USA, to examine the relation between groundwater extraction, precipitation, terrain position, and cover collapse sinkhole development. The selected site is unique as a natural laboratory to explore induced sinkhole processes in that it is a clearly demarcated topographic basin with geological structural and lithologic boundaries; the stressor is extreme, has been plainly identified, and effectively captures all upstream runoff and groundwater; the groundwater withdrawals and water-level elevations have been closely monitored over a period of 20 years; and the general record of land conditions goes back more than a century. We evaluated the history of a carbonate-rock quarry, its development and expansion over many decades, as well as associated precipitation and ground-water level data, and cover collapse sinkhole occurrence within the basin. Interception of discrete high conductivity zones in the Paleozoic carbonate rocks by quarry expansion was an important factor in propagating collapse occurrence. Collapses occurred mainly, though not exclusively, along drainageways and at lithologic boundaries. They formed in time-based clusters with delay of up to several years. Surprisingly, distance of collapse formation from the pumping area was not directly correlated with time elapsed; i.e., collapses did not begin to form close to the quarry, and then later form farther away. Monitoring wells were unsuccessful in delineating the pumping zone of influence although some documented water table decline and response to weather and anthropogenic events. This comprehensive study shows that in order to successfully monitor and control impacts from quarry dewatering in Paleozoic carbonate rocks it is critical to 1) develop a detailed conceptual model of groundwater pathways, 2) try to avoid excavating into high permeability zones, 3) clearly document karst features when exposed, and 4) carefully site a suitable number of monitoring wells and collect data at short intervals.

Significance of heat and mass transport in peristaltic flow of Jeffrey material subject to chemical reaction and radiation phenomenon through a tapered channel

Abstract Using mathematical modeling and computational analysis, this study aims to examine the peristaltic blood flow of a non-Newtonian material in a tapered channel with radiative heat flux and response mechanisms. By utilizing a long-wavelength approximation, ignoring the wave number, and performing under conditions of low Reynolds number, closed form solutions for the velocity, temperature, and concentration fields are achieved. Several governing parameters and their effects on the system were analyzed, and relevant diagrams were provided. Increasing the Biot number, Jeffrey material, and thermal radiation parameter of the heat and mass transfer mechanism increases the velocity profile. When the heat source/sink parameter and the heat transfer Biot number increase, the temperature profile improves. The resultant concentration distributions are enhanced when mass transfer Biot number, heat radiation, and chemical processes are all raised. We observe that the pressure rate decreases in all three pumping zones when the heat transfer Grashof number and heat transfer Biot number rise. This is because the pressure rate is affected by the Grashof number and Biot number of heat transmission. The increase in thermal radiation parameter and heat transfer Biot number results in a slower rate of heat transfer than when Prandtl number and heat source/sink parameter increases. When the Soret number, Schmidt number, Biot number, and heat source/sink parameter are all raised, the mass transfer coefficient also rises. This rate, however, decreases as the heat radiation and chemical reaction parameters rise. The findings presented in this study have interesting implications for other aspects of human physiology. The preponderance of organs are permeable. Furthermore, fluids render the location of natural boundaries uncertain. The presented mathematical model can be used to derive predictions about the behavior of various systems. For the study of cancer treatment in biological systems, a mathematical model that includes nanoparticles, viscosity dissipation, and rotation holds much promise. Model development incorporated Soret–Dufour effects and thermal analysis of the digestive system.

The effects of diffusion on the mechanism of peristaltic flow at slip boundaries when internal Joule heating is present

AbstractPhysiological applications of the study of heat transfer and peristaltic pumping of magnetohydrodynamic thermal diffusion include heart–lung machines during surgery, dialysis, vitamin injections, and cancer treatment. In addition, it has numerous industrial applications, including pharmaceutical fluid production, filtration, and contamination‐free cosmetic and glue emulsion dispensing. Studying the influence of diffusion‐thermo and thermal diffusion on peristaltic flow with slip boundaries propelled by internal Joule energy is the key motivation for this study. By utilizing a long‐wavelength approximation, ignoring the wave number, and performing under conditions of low Reynolds number, closed‐form solutions for the velocity, temperature, and concentration fields are achieved. Fluid flow along the axial pressure gradient tends to decrease as slip parameters increase. It is shown that when the amount of the second‐order slipping parameter increases, the pressure rate decreases in the back and peristaltic pumping zones but increases in the copump zone. The fluid's temperature and concentration tend to decrease as the slip parameters increase. Changes in thermal diffusion and thermo‐diffusion factors cause changes in the fluid's temperature and concentration. The Nusselt number improves as a result of increasing the Prandtl number, thermo‐diffusion constraint, Dufour number, and Schmidt number, whereas the Sherwood number exhibits the reverse trend.

Reactive transport modeling for the effect of pumping activities on the groundwater environment in muddy coasts

Intensive pumping activities threaten the coast groundwater environment and have a negative impact on aquifer systems. A comprehensive understanding of these effects is important for the management of coastal groundwater resources. However, this is challenging, particularly for coastal saline groundwater systems due to complex water–rock interactions. In this study, a coupled variable–density flow and hydrochemical reaction model was used to examine the effects of pumping activities on the groundwater environment on the southern coast of Laizhou Bay, China, which is a typical muddy coast. The model successfully captured the hydrodynamic and hydrochemical changes, and the water–rock interactions, during three different exploitation stages: (1) evaporation and water–rock interactions were the primary controls on groundwater evolution during the weakly pumped stage (before 1995); (2) the groundwater level began to decrease and saltwater intrusion was aggravated during the small pumping stage (1995–2005); and (3) significant hydrodynamic and hydrochemical changes occurred at the saline/freshwater transition and pumping zones during a period of intensive pumping (after 2005). Our findings revealed that water–rock interactions are the primary drivers of hydrochemical evolution at the saline/freshwater transition and seaward saline groundwater zone, whereas hydrodynamic changes are the main drivers in the pumping and deep saline–brine water zones. Furthermore, we discussed the effects of hydrodynamic variations and water–rock interactions on the aquifer matrix and identified that irreversible changes occurred mainly in the pumping zone and saline/freshwater transition. In conclusion, our study highlights the importance of considering both hydrodynamic and hydrogeochemical factors when managing coastal groundwater resources. By developing a better understanding of these complex interactions, we can minimize the negative impacts of pumping activities and preserve the long-term sustainability of coastal groundwater resources.

Sustainable design and development of commercial system cleanser unit for trimmers

A product design and development process has been adopted to study and improve the sustainability of trimmer System Cleanser. A hair trimmer with liquid detergent in cartridge is fixed as a cleaner system to design and analyse. The 3D model of the system is designed with NX CAD software. The modification is cartridge unit is made on counter face to increase the turbulence of the fluid in the wash zone. The file has been extracted and imported in LS Dyna for meshing the model for detergent liquid flow analysis. The velocity vector and pressure magnitude of the fluid flow is analysed through a StarCCM + higher fluid analysis software. The input process condition of the pump in cartridge assemble unit has a speed 2000 rpm and velocity of the liquid as 1 m/s. From the analysis, the suction pressure noticed at the pump zone is 950 Pa and the discharge of fluid in the pump is 850–900 Pa at wash zone. Difference in fluid velocity found decreased and it is in the range of 0.8 to 0.95 m/s. The predominant factor in the design is alternate openings in case baffle has increased the turbulence in pressure and the velocity of the fluid found same.

Transient behavior of two-stage load rejection for multiple units system in pumped storage plants

Pumped storage plants (PSPs) are being rapidly deployed and developed since they are cost-effective and mature energy storage solutions to the penetration of renewable energy sources (RES). Hydraulic transient analysis on PSPs, especially under extreme operating conditions such as two-stage load rejection (LR), is the key to safe hydraulic system design. Two-stage LR, involving a step-wise reduction in load, may induce extremely low draft tube pressure (DTP), directly threatening the safety of a multiple units PSP. Using numerical simulation, this study systematically investigates the behavior of the hydraulic parameters, and reveals the mechanism leading to the extremely low DTP during a two-stage LR process. The results indicate that the asynchronously varying discharge, coming from the inconsistent instants of time rejecting load and subsequent pressure difference, is the origin of severe reverse water hammer. Furthermore, the rate of discharge change of the subsequent load rejection turbine (SLRT) is confirmed to be the critical factor. The unexpected low DTP occurs exactly when its rate of discharge change reaches its minimum value. Additionally, the deeper the moving trajectory of the SLRT enters the reverse pump zone, the more severe the low DTP will be. Finally, two engineering measures that can economically and effectively improve the minimum DTP are proposed based on the hydraulic behavior of two-stage LR.

Electrochemical Behavior of 2M5S and Its Influence on Reduction of Cu Pumping and Keep-Out Zone

Previously, we have reported the low thermal expansion copper electrodeposited in solution containing 2-Mercapto-5-benzimidazolesulfonic acid sodium salt dihydrate (2M5S). In this research, we investigated the electrochemical behavior 2M5S additive by CVS and LSV measurements. The 2M5S additive showed an inhibition effect during electrodeposition of copper, both in the absence and presence of Cl−. Using a combination of the 2M5S leveler with another SDDACC leveler and SPS accelerator, the thermal expansion of copper was reduced and the TSV was filled without defects. The SEM results showed that the copper pumping height of low TEC copper in PECVD SiO2 TSV was only 0.5 μm. Meanwhile, the copper pumping height of reference conventional copper in PECVD SiO2 TSV was about 2 μm. Furthermore, compared with thermal stress curve in Si around the conventional copper TSV, thermal stress curve in Si around the low TEC copper TSV was much lower and the KOZ also was reduced to about 1 μm.

Microfabrication of a Silicon Turbopump with Embedded Thermal Isolation for a Rankine MEMS Heat Engine

This paper presents the fabrication of a silicon MEMS microturbopump with embedded thick thermal isolation, covering the key building blocks to incorporate thermally insulated zones in a multiple wafer stack, and the resulting device. Thermal insulation is a roadblock for the implementation of heat engines at the MEMS scale. To implement the Rankine cycle on a chip, insulation is required to prevent boiling of water in the pump while the turbine is exposed to high temperature vapour flows. To prevent heat from conducting through the silicon rotor, thick glass insulation was embedded into the rotor structure using glass molding and planarization. This composite rotor approach allows us to leverage the capabilities of silicon DRIE, while creating over 100 micron thick glass insulation between the turbine and the pump. Also, in-plane thermal insulation is required between the central pump zone and the surrounding fluid film bearings, fed with steam. This was accomplished by etching deep trenches in silicon to form an array of thin walls, followed by a thermal oxidation step that consumes the silicon walls and closes the trenches to form a deep monolithic oxide zone. These techniques were successfully implemented for the fabrication of a complete MEMS turbopump, which consists of a stack of 4 silicon wafers and one glass wafer, and a total of 18 lithography/etch steps.

Cilia-assisted hydromagnetic pumping of biorheological couple stress fluids

A theoretical study is conducted for magnetohydrodynamic pumping of electro-conductive couple stress physiological liquids (e.g. blood) through a two-dimensional ciliated channel. A geometric model is employed for the cilia which are distributed at equal intervals and produce a whip-like motion under fluid interaction which obeys an elliptic trajectory. A metachronal wave is mobilized by the synchronous beating of cilia and the direction of wave propagation is parallel to the direction of fluid flow. A transverse static magnetic field is imposed transverse to the channel length. The Stokes’ couple stress (polar) rheological model is utilized to characterize the liquid. The normalized two-dimensional conservation equations for mass, longitudinal and transverse momentum are reduced with lubrication approximations (long wavelength and low Reynolds number assumptions) and feature a fourth order linear derivative in axial velocity representing couple stress contribution. A coordinate transformation is employed to map the unsteady problem from the wave laboratory frame to a steady problem in the wave frame. No slip conditions are imposed at the channel walls. The emerging linearized boundary value problem is solved analytically and expressions presented for axial (longitudinal) velocity, volumetric flow rate, shear stress function and pressure rise. The flow is effectively controlled by three geometric parameters, viz cilia eccentricity parameter, wave number and cilia length and two physical parameters, namely magnetohydrodynamic (MHD) body force parameter and couple stress non-Newtonian parameter. Analytical solutions are numerically evaluated with MATLAB software. Axial velocity is observed to be enhanced in the core region with greater wave number whereas it is suppressed markedly with increasing cilia length, couple stress and magnetic parameters, with significant flattening of profiles with the latter two parameters. Axial pressure gradient is decreased with eccentricity parameter whereas it is elevated with cilia length, in the channel core region. Increasing couple stress and magnetic field parameter respectively enhance and suppress pressure gradient across the entire channel width. The pressure-flow rate relationship is confirmed to be inversely linear and pumping, free pumping and augmented pumping zones are all examined. Bolus trapping is also analyzed. The study is relevant to MHD biomimetic blood pumps.

Identifying Agricultural Systems Using SVM Classification Approach Based on Phenological Metrics in a Semi-arid Region of Morocco

To understand changes in agricultural systems, it is necessary to monitor vegetation dynamics based on the spatio-temporal characterization of phenological parameters. The purpose of this study is to identify the main agricultural systems using a phenology-based classification method in a semi-arid context. Phenological metrics were derived from Normalized Difference Vegetation Index time series extracted from MOD13Q1 product between 2012 and 2016. Furthermore, Support Vector Machine classification method was applied based on phenological metrics, to identify the main agricultural system classes in the study area. The main classes are; (1) irrigated annual crop, (2) irrigated perennial crop, (3) rainfed area and (4) fallow. The classification overall accuracy reached 88%, with a kappa coefficient of 0.83 and values of F1-score greater than 0.76. The results demonstrated the ability of phenological parameters to identify and monitor the main agricultural system classes in the study area and to control the illegal pumping zones.

An Integrated Approach Toward Sustainability via Groundwater Banking in the Southern Central Valley, California

AbstractIntensive groundwater withdrawals in California have resulted in depletion of streams and aquifers in some regions. Agricultural managed aquifer recharge (Ag‐MAR) initiatives have recently been piloted in California to mitigate the effects of unsustainable groundwater withdrawals. These initiatives rely on capturing wet‐year water and spreading it on large areas of irrigated agricultural lands to enhance recharge to aquifers. While recharge studies typically consider local effects on aquifer storage, few studies have investigated Ag‐MAR benefits and challenges at a regional scale. Here we used the Integrated Water Flow Model, to evaluate how Ag‐MAR projects can affect streamflows, diversions, pumping, and unsaturated zone flows in the southern Central Valley, California. We further tested the sensitivity of three different spatial patterns of Ag‐MAR, each chosen based on different thresholds of soil suitability, on the hydrologic system. This study investigates how the distribution of Ag‐MAR lands benefit the regional groundwater system and other water balance components. The results suggest that Ag‐MAR benefits vary as a function of the location of Ag‐MAR lands. Stream‐aquifer interactions play a crucial factor in determining the ability to increase groundwater storage in overdrafted basins. The results also indicate that Ag‐MAR projects conducted during the November–April recharge season have implications for water rights outside of the Ag‐MAR season. If not properly monitored, Ag‐MAR can cause a rise of groundwater table into the root zone, negatively impacting sensitive crops. Our work also highlights the benefits of using an integrated hydrologic and management model to evaluate Ag‐MAR at a regional scale.

POWER SCALING IN CONTINUOUS-WAVE YB:YAG MICROCHIP LASER FOR MEASURING APPLICATIONS

Characteristics optimization of lasers used in different measuring systems is of great interest up to now. Diode-pumped microchip lasers is one of the most perspective ways for development of solid-state light sources with minimal size and weight together with low energy power consumption. Increasing of output power with good beam quality is rather difficult task for such type of lasers due to thermal effects in the gain crystal under high pump power.The investigation results of continuous-wave longitudinally diode-pumped Yb:YAG microchip laser are presented. In the presented laser radiation from multiple pump laser diodes were focused into the separate zone in one gain crystal that provides simultaneous generation of multiple laser beams. The energy and spatial laser beam characteristics were investigated.Influence of neighboring pumped regions on energy and spatial laser beams parameters both for separate and for sum laser output was observed. The dependences of laser output power from distance between neighboring pumped regions and their number were determined. Decreasing of laser output power was demonstrated with corresponding distance shortening between pumped regions and increasing their quantity with simultaneous improvement of laser beam quality.Demonstrated mutual influence of neighboring pumped regions in the longitudinally diode pumped Yb:YAG microchip laser allow as to generate diffraction limited Gaussian beam with 2W of continuous-wave output power that 30 % higher than in case of one pumped zone.

Геолого-гідрогеологічна історія розвитку вугільної промисловості Західного Донбасу в математичних моделях.

Constantly operating mathematical model it regional, multifunction hydrogeological task. A model limits in space and endless in time. General description of technogenic changes of the mode of underwaters it is the main flaw. Based on this for development of nature protection measures to the hydrogeological orientation a regime model cannot be only foundation. Therefore it is complemented by the mathematical models of territories that fit closely to the local objects of technogenic influence on underwaters. In hired the mathematical models of change of hydrogeological terms of territory are examined in the affected of the mine pumping zone A model consists of two parts - lauter and migratory. Filtration in a general view is described by three-dimensional equalizations of mathematical physics of parabolic kind in partials. Three theories - filtration, physical and chemical hydrodynamics of porous environments and mining holes fixed in basis of creation of mathematical models of change of hydrogeological terms of territories. On the basis of theory of physical and chemical hydrodynamics of porous environments the modern methods of prognosis of transfer of substance were worked out underground to waters near-by the sources of contamination. In obedience to this theory processes are described by equalizations of motion and maintenance of mass of substance. These territories fit closely to the technogenic objects of negative influence on underwaters. Sequence of putting into the operation of coal mines, their lowering action, closing variants mining holes on mathematical models represented in a chronological order on the basis of theory of single and interactive mining holes. Adequacy of models and originals is confirmed by regime supervisions on mining holes in the affected of the mine pumping zone. Conducting work it is possible to draw conclusion that the theory of mining holes is applicable at the decision of tasks of the mine pumping. At influence of pumping on adherent territories in the process of exploitation and in connection with closing of mines.Constantly operating mathematical model it regional, multifunction hydrogeological task. A model limits in space and endless in time. General description of technogenic changes of the mode of underwaters it is the main flaw. Based on this for development of nature protection measures to the hydrogeological orientation a regime model cannot be only foundation. Therefore it is complemented by the mathematical models of territories that fit closely to the local objects of technogenic influence on underwaters. In hired the mathematical models of change of hydrogeological terms of territory are examined in the affected of the mine pumping zone A model consists of two parts - lauter and migratory. Filtration in a general view is described by three-dimensional equalizations of mathematical physics of parabolic kind in partials. Three theories - filtration, physical and chemical hydrodynamics of porous environments and mining holes fixed in basis of creation of mathematical models of change of hydrogeological terms of territories. On the basis of theory of physical and chemical hydrodynamics of porous environments the modern methods of prognosis of transfer of substance were worked out underground to waters near-by the sources of contamination. In obedience to this theory processes are described by equalizations of motion and maintenance of mass of substance. These territories fit closely to the technogenic objects of negative influence on underwaters. Sequence of putting into the operation of coal mines, their lowering action, closing variants mining holes on mathematical models represented in a chronological order on the basis of theory of single and interactive mining holes. Adequacy of models and originals is confirmed by regime supervisions on mining holes in the affected of the mine pumping zone. Conducting work it is possible to draw conclusion that the theory of mining holes is applicable at the decision of tasks of the mine pumping. At influence of pumping on adherent territories in the process of exploitation and in connection with closing of mines.Keywords: mathematical model, theory of wells, regime observations, adequacy, theory of mining, underground waters.

Ionic liquid flow along the carbon nanotube with DC electric field.

Liquid pumping can occur along the outer surface of an electrode under a DC electric field. For biological applications, a better understanding of the ionic solution pumping mechanism is required. Here, we fabricated CNT wire electrodes (CWEs) and tungsten wire electrodes (TWEs) of various diameters to assess an ionic solution pumping. A DC electric field created by a bias of several volts pumped the ionic solution in the direction of the negatively biased electrode. The resulting electro-osmotic flow was attributed to the movement of an electric double layer near the electrode, and the flow rates along the CWEs were on the order of picoliters per minute. According to electric field analysis, the z-directional electric field around the meniscus of the small electrode was more concentrated than that of the larger electrode. Thus, the pumping effect increased as the electrode diameter decreased. Interestingly in CWEs, the initiating voltage for liquid pumping did not change with increasing diameter, up to 20 μm. We classified into three pumping zones, according to the initiating voltage and faradaic reaction. Liquid pumping using the CWEs could provide a new method for biological studies with adoptable flow rates and a larger ‘Recommended pumping zone’.

Evaluation of the depressurization based technique for methane hydrates reservoir dissociation in a marine setting, in the Krishna Godavari Basin, east coast of India

This paper analyses the effectiveness of the depressurization technique for methane gas production from an unconfined gas hydrate setting in the Krishna Godavari Basin of India. TOUGH + HYDRATE reservoir modeling and production simulation software is used for identifying the depressurization range for sustained dissociation. For the identified depressurization range, a borehole based pumping technique is modeled using MATLAB software, to identify the effectiveness of the technique in dissociating the reservoir with post-dissociation permeability (PDP) ranging between 1 and 500 mD, the likely scenario for the KG basin. The results indicate that the depressurization technique shall be effective for reservoirs with higher PDP, while the reach of the bore well depends on the capacity of the pump and hydrate zone well perforation area. The simulation results indicate that a bore well with 50 m2 of hydrate zone surface area could be effective in dissociating the reservoir up to a distance of 1000 m, with a pump of 128 kW electric capacities in formations with PDP of 500 mD. The results could serve as a basis for the economic planning of production wells in gas hydrate reservoirs.

Effects of Groundwater Withdrawal on the Interaction of Ex-Mining Pond, River, and Aquifer

The paper aims at evaluating the effects of groundwater abstraction on the interaction of an ex-mining pond, river, and aquifer system of the Langat Basin in Malaysia through a 3D numerical modeling. Many mining sites have been left behind from the massive mining exploitation in Malaysia. In the current study, an artificial recharge from an ex-mining pond in the Langat Basin was proposed due to its capacity to store >30 million m3 of water. The 3D numerical model was developed using the Visual MODFLOW to simulate the effects of these activities. The calibrated model was utilized to simulate two cases. The ex-mining pond was without and with pumping in Case 1 and 2, respectively. Both results showed that the pond and aquifer were in influent condition. In Case 1, the total inflow to the aquifer system were approximately 15,819 m3/d of water from the constant heads, 1,202 m3/d from the Langat River, and 66,951 m3/d from the direct recharge of precipitation. In Case 2, due to the abstraction of groundwater, it caused a steep depression around the pumping well, river, and pond. The result of the water budget showed an increase rate of the inflow to the pumping zone from the pond and river around 6,945 m3/d compared to Case 1. The outcome of the current study provides the useful information of the interactions between the river, pond, and aquifer system as regards the groundwater abstraction in the Langat Basin.

Particle tracking analysis of river–aquifer interaction via bank infiltration techniques

Induced bank infiltration (BI) is commonly implemented in other countries, but remains new and unexplored in Malaysia. Increasing river pollution could affect drinking water resources. Given the threat of pollution to raw water sources, applying induced BI to sustain water management is essential. This paper presents a case study of the BI method, which evaluates the effects of groundwater pumping and BI operation on the installation of wells as well as determines the effect of pumping rate on flow paths, travel time, the size of the pumping and capture zone delineation, and groundwater mixing in a pumping well in Jenderam Hilir, Malaysia. The proposed method performs infiltration safely and achieves the ideal pumping rate. Numerical modeling packages, MODFLOW and MODPATH (particle tracking) were used. Results indicate that the migration of river water into the aquifer is generally slow and depends on the pumping rate and distance from well to the river. Most water arrives at the well by the end of a pumping period of 1–5 days at 3,072 m3/day for test wells DW1 and DW2, and during simultaneous pumping for DW2 and PW1 for a well located 36 and 18 m, respectively, from the river. During the 9.7-day pumping period, 33 % of the water pumped from the DW1 well was river water, and 38 % from DW2 throughout 4.6 days was river water. The models provide necessary information for water operators in the design and construction of pumping and sampling schedules of BI practices.

Using particle tracking as a tool sustainable bank infiltration techniques: a case study in an alluvial area

This study was inspired by the Klang Valley water crisis, for which bank infiltration (BI) is considered a potential solution. This paper presents a case study of the BI techniques, which evaluates the effects of groundwater pumping and BI operation on the installation of wells. This study also determines the effect of pumping rate on flow paths, travel time, the size of the pumping and capture zone delineation, and groundwater mixing in a pumping well in Jenderam Hilir, Malaysia. The proposed method performs infiltration safely and achieves the ideal pumping rate. Numerical modeling packages, MODFLOW and MODPATH (particle tracking) were used. Results indicate that the migration of river water into the aquifer is generally slow and depends on the pumping rate and distance from well to the river. Most water arrives at the well by the end of a pumping period of 1 to 5 days at 3,072 m3/day for test wells DW1 and DW2, and during simultaneous pumping for DW2 and PW1 for a well located 36 and 18 m, respectively, from the river. During the 9.7-day pumping period, 33 % of the water pumped from the DW1 well was river water, and 38 % of the water pumped from DW2 throughout 4.6 days was river water.