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This study investigates cloud cavitation suppression around a model-scale NACA66 hydrofoil using active water injection and explores the effect of multiple injection parameters. Numerical simulations and a mixed-level orthogonal test method are employed to systematically analyze the impact of jet angle αjet, jet location Ljet, and jet velocity Ujet on cavitation suppression efficiency and hydrofoil energy performance. The study reveals that jet location has the greatest influence on cavitation suppression, while jet angle has the greatest influence on hydrofoil energy performance. The optimal parameter combination (Ljet = 0.30C, αjet = +60 degrees, Ujet = 3.25 m/s) effectively balances energy performance and cavitation suppression, reducing cavitation volume by 49.34% and improving lift–drag ratio by 8.55%. The study found that the jet’s introduction not only enhances vapor condensation and reduces the intensity of the vapor–liquid exchange process but also disrupts the internal structure of cavitation clouds and elevates pressure on the hydrofoil suction surface, thereby effectively suppressing cavitation. Further analysis shows that positive-going horizontal jet components enhance the lift–drag ratio, while negative-going components have a detrimental effect. Jet arrangements near the trailing edge negatively impact both cavitation suppression and energy performance. These findings provide a valuable reference for selecting optimal injection parameters to achieve a balance between cavitation suppression and energy performance in hydrodynamic systems.

Due to the present alarming environmental problem, the world has turned to photovoltaic (PV) solar energy as a sustainable, renewable, and environmentally friendly alternative. Solar energy technology has rapidly improved in recent decades, and the global installation of photovoltaic systems has been increasing at a rate of 24% annually. However, soiling on panels and high panel temperature affect the performance of photovoltaic systems, and this leads to significant production loss, especially in the Middle East, where the dust intensity and ambient air temperature are at their highest levels. This paper presents the influence of cooling and interval cleaning on the performance of the photovoltaic system installed in Muscat, Oman. The study involved cleaning the first panel at a comparable inclination angle. The second panel had its inclination angle changed. The third panel was designed to inject water for cooling purposes. In this case, the panel was subjected to water injection for 30 s once per week, followed by daily water injection for 120 s in the second week. All the results were compared with the fourth panel, which was neither cleaned nor touched. Measurements, including open circuit voltage, short circuit current, solar panel temperature, solar radiation, and power, were made in 1-min intervals using a data logger. The results of the experiment showed that cleaning the panel manually every three days resulted in the highest output power and efficiency, reaching 85.6 W with 23.6% efficiency. The cooling of the panel resulted in an increase in power, especially for the longer injection duration. Conclusively, water injection resulted in an energy output growth of 23.9%.

Abstract It is necessary to improve oil production from reservoirs. Various methods have been proposed to increase oil extraction from reservoir. Each method has specific challenges. In this research, the effect of water and gas injection in to Azadegan reservoir has been analyzed. Azadegan oil field is located south of Iran. In this study, water, immiscible gas and water alternating gas injected to reservoir and its effect on enhanced oil recovery have been investigated. Finally, a comparison between results of methods is provided. Results show that effective method for enhanced oil recovery is immiscible gas injection with 46% oil production efficiency and water alternating gas injection with 36% oil production efficiency. This study shows that oil production efficiency can be increased if duration of gas injection is increased. This study shows, increasing viscosity of water in water alternating gas scenario did not improve the production of Azadegan reservoir.

To resolve the water-blocking effect that reduces gas extraction after implementing hydraulic measures, alkyl polyglycoside (APG) and polyacrylamide (PAM) were used to treat coal samples to make wettability enhancement and medium wettability conversion, respectively. The contact angle, surface tension, solid surface energy, infrared spectroscopy, and high-pressure water injection desorption were performed to investigate the effects of reagents on the wettability alteration mechanism and desorption characteristics of coal. The results demonstrated that the surface energy, hydrogen bonds and oxygen-containing functional groups of coal alter wettability and gas desorption. The APG-treated coal samples exhibited increased surface energy, hydrogen bonds and oxygen-containing functional groups, whereas the PAM-treated coal samples demonstrated the opposite trend. The surface energy of coal reflects the state of APG and PAM molecules adsorbed on the coal surface, and the polar force of surface energy in coal follows a quadratic relationship with the volume of gas displacement desorption. Increasing the number of hydrogen bonds and oxygen-containing functional groups can improve wettability and decrease the interaction force between coal and methane molecules. This contributes to the lower atmospheric desorption of the APG-treated coal samples at high pressure. The total desorption volume of the APG-treated coal samples was 10–34% of that of the original coal at 0.737, 1.027, and 2.004 MPa gas pressures. The total desorption volume of PAM-treated samples at 2.004 MPa was 2.3474 cm3/g, which exceeded that of the original coal. Therefore, APG and PAM promoted gas desorption, and wettability enhancement yielded better results. This study provides an experimental approach for selecting the best reagent and excellent guidance for field applications. [Display omitted] [ABSTRACT FROM AUTHOR]

Recently, water injection has been widely studied as one of the most popular enhanced/improved oil recovery methods. Most of the studies focus on low salinity and seawater injection, emphasizing the quality of the injection fluid. In addition, receiving the required quantity of injection water and high-quality injection fluid is crucial. Produced water with oil and urban wastewater can be regarded as appropriate resources for water injection projects to mitigate the environmental concerns and the cost of water treatment. This study examines several water resources suggested for injection into an oil reservoir near the Persian Gulf to find the optimal choice. The studied resources are low-salinity water, seawater (from the Persian Gulf), produced water, and urban wastewater. Injection fluid quality, compatibility with formation brine, scale formation, and usability were the primary factors considered when selecting the optimal water resource. Accordingly, geo-chemical software OLI Scale Chem was used for compatibility check and estimation of scale type and amount. As a result, the least amount of scale formed after urban wastewater injection, whereas seawater was the most incompatible water source. It should be emphasized that various non-technical factors, such as the climate of the region, the water transmission route and associated costs, economic conditions of the country, environmental concerns, and the priority of wastewater usage may significantly impact resource selection. [ABSTRACT FROM AUTHOR]

The amount of heat transferred from the combustion chamber directly affects the combustion efficiency. Increasing the amount of heat transfer reduces the combustion efficiency. With thermal coating methods in engines, the amount of heat transfer is reduced and the combustion efficiency is increased. However, covering the entire combustion chamber with thermal material causes an increase in the knocking tendency and worsening of emission values in spark ignition engines. With the water injection method, emission values can be reduced significantly without worsening engine performance parameters. In the study, the upper surface of the piston was partially covered with MgOZrO2 ceramic material with high heat reserve in order to increase the engine efficiency. The coated engine was sprayed with water into the intake manifold at 10%, 20% and 30% by mass of instantaneous fuel consumption. By using the two methods at the same time, improvements in performance parameters and exhaust emissions have been achieved. In the TBL piston engine, power, torque, specific fuel consumption, effective efficiency and HC emissions improve, while NOx emissions increase. In the case of water injection into the intake manifold, the increased NOx emissions decrease without any deterioration in performance parameters. Improvements were found in engine torque and effective power by 4.1%, specific fuel consumption by 3.8% and effective efficiency by 3.9% at 20% water injection rate. Compared to standard engine data, a 20% reduction was achieved in NOx emissions at 30% water injection rate. In addition, reductions of up to 33% were detected in HC emissions at 20% water spraying rate. [ABSTRACT FROM AUTHOR]

We present results from an international model comparison study involving a series of controlled fault activation experiments in Opalinus Clay at the Mont Terri Laboratory, Switzerland. The fault activation experiments were conducted in situ by water injection at variable pressure from boreholes targeting different parts of the Main Fault crossing several tunnels and galleries of the Mont Terri Laboratory. The model simulations focused on (1) an experiment activating a discontinuity (fracture or minor fault) within the damage zone of the main fault, and (2) an experiment activating discontinuities close to the core of the Main Fault. The experimental data consist of coupled hydraulic and mechanical responses monitored at an injection borehole and a monitoring borehole located a few meters away. After overcoming several modeling issues along with necessary model developments, a reasonably good agreement was achieved between the modeling results and the field observations. The fault activation experiments displayed an abrupt flow rate increase associated with a sudden fracture opening and rupture propagation after the injection pressure reached above the estimated normal stress on the fracture. This was followed by an abrupt flow rate decrease, indicating hydraulic closing, once the injection pressure decreases to an estimated 1–2 MPa below the stress normal to the opened fracture. The models were able to capture this abrupt hydromechanical behavior, including an observed dominant opening behavior along with the rupture propagation, while the spatial extent of the shear rupture and the quantity of peak injection flow were the most challenging to predict.

We present results from an international model comparison study involving a series of controlled fault activation experiments in Opalinus Clay at the Mont Terri Laboratory, Switzerland. The fault activation experiments were conducted in situ by water injection at variable pressure from boreholes targeting different parts of the Main Fault crossing several tunnels and galleries of the Mont Terri Laboratory. The model simulations focused on (1) an experiment activating a discontinuity (fracture or minor fault) within the damage zone of the main fault, and (2) an experiment activating discontinuities close to the core of the Main Fault. The experimental data consist of coupled hydraulic and mechanical responses monitored at an injection borehole and a monitoring borehole located a few meters away. After overcoming several modeling issues along with necessary model developments, a reasonably good agreement was achieved between the modeling results and the field observations. The fault activation experiments displayed an abrupt flow rate increase associated with a sudden fracture opening and rupture propagation after the injection pressure reached above the estimated normal stress on the fracture. This was followed by an abrupt flow rate decrease, indicating hydraulic closing, once the injection pressure decreases to an estimated 1–2 MPa below the stress normal to the opened fracture. The models were able to capture this abrupt hydromechanical behavior, including an observed dominant opening behavior along with the rupture propagation, while the spatial extent of the shear rupture and the quantity of peak injection flow were the most challenging to predict.

The present study is aimed at developing a numerical model to reproduce coupled hydro-mechanical processes associated with fault reactivation by fluid injection in low permeability rock, as part of the DECOVALEX-2019 project Task B. We proposed a modeling approach for simulating the processes using the TOUGH-FLAC simulator, and modeled a fault reactivation experiment conducted at Mont Terri Rock Laboratory in Switzerland. The first step of the study involved benchmark calculations considering a simplified fault plane and geometry. Fluid flow along a fault was modeled using elements of aperture-sized thickness on the basis of Darcy's law and the cubic law in TOUGH2, whereas the mechanical behavior of a single fault was represented by zero-thickness interface elements in FLAC3D upon which a slip and/or separation is allowed. A methodology to connect a TOUGH2 volume element to a FLAC3D interface element was developed for handling the hydro-mechanical interactions on the fault during fluid injection. Two different fault models for describing the evolutions of hydraulic aperture by elastic fracture opening and failure-induced aperture increase were considered in the benchmark calculations. In the coupling process, the changes in geometrical features and hydrological properties induced by mechanical deformation were continuously updated. The transient responses of the fault and host rock to stepwise pressurization were examined during the simulation. The hydro-mechanical behavior, including the injection flow rate, pressure distribution around the borehole, stress conditions, and displacements in normal and shear directions were monitored in the surrounding rock and along the fault. The results of benchmark calculations suggest that the developed model reasonably represents the hydro-mechanical behavior of a fault and the surrounding rock. This modeling approach was applied to the fault reactivation experiment of the Mont Terri Rock Laboratory. In this interpretive modeling, a parametric study was conducted to examine the effects of input parameters regarding in situ stress and fault properties on the hydro-mechanical responses of the fault to water injection. Then, an optimal parameter set to reproduce the field experiment results was chosen by trial-and-error. The injection flow rate and pressure response during fault reactivation closely matched those obtained at the site, which indicates the capability of the model to appropriately capture the progressive pathway evolution during fault reactivation tests at the site. The anchor displacements were overestimated by the model, but a fair agreement was obtained in terms of the order of magnitude and the variation tendency.

The present study is aimed at developing a numerical model to reproduce coupled hydro-mechanical processes associated with fault reactivation by fluid injection in low permeability rock, as part of the DECOVALEX-2019 project Task B. We proposed a modeling approach for simulating the processes using the TOUGH-FLAC simulator, and modeled a fault reactivation experiment conducted at Mont Terri Rock Laboratory in Switzerland. The first step of the study involved benchmark calculations considering a simplified fault plane and geometry. Fluid flow along a fault was modeled using elements of aperture-sized thickness on the basis of Darcy's law and the cubic law in TOUGH2, whereas the mechanical behavior of a single fault was represented by zero-thickness interface elements in FLAC3D upon which a slip and/or separation is allowed. A methodology to connect a TOUGH2 volume element to a FLAC3D interface element was developed for handling the hydro-mechanical interactions on the fault during fluid injection. Two different fault models for describing the evolutions of hydraulic aperture by elastic fracture opening and failure-induced aperture increase were considered in the benchmark calculations. In the coupling process, the changes in geometrical features and hydrological properties induced by mechanical deformation were continuously updated. The transient responses of the fault and host rock to stepwise pressurization were examined during the simulation. The hydro-mechanical behavior, including the injection flow rate, pressure distribution around the borehole, stress conditions, and displacements in normal and shear directions were monitored in the surrounding rock and along the fault. The results of benchmark calculations suggest that the developed model reasonably represents the hydro-mechanical behavior of a fault and the surrounding rock. This modeling approach was applied to the fault reactivation experiment of the Mont Terri Rock Laboratory. In this interpretive modeling, a parametric study was conducted to examine the effects of input parameters regarding in situ stress and fault properties on the hydro-mechanical responses of the fault to water injection. Then, an optimal parameter set to reproduce the field experiment results was chosen by trial-and-error. The injection flow rate and pressure response during fault reactivation closely matched those obtained at the site, which indicates the capability of the model to appropriately capture the progressive pathway evolution during fault reactivation tests at the site. The anchor displacements were overestimated by the model, but a fair agreement was obtained in terms of the order of magnitude and the variation tendency.

Recently, water injection-induced earthquakes caused by faulting instability have become a prominent geological safety issue for safely exploiting deep geothermal resources. This study investigates whether the future large-scale development of deep geothermal resources in the Gaoyang uplift will destabilize buried faults. There has a great amount of karst thermal reservoir in the Gaoyang low uplift, Hebei province. To find out whether the large-scale deep geothermal exploitation in the future will induce faults distributed in and around Gaoyang geothermal reservoir to become unstable, firstly, we calculate the initial stable state of the main buried faults based on Mohr-Coulomb criteria using the comprehensive in-situ stress field of North China; then, under Hsieh and Bredehoeft hydrological model, we calculate the possible excess pore pressure caused by water injection for 10~40 years at representative geothermal wells; subsequently, combing this perturbation with the initial stable state, we obtain the fault slip potential of the main buried faults from 2022 to 2062 based on a probabilistic approach; ultimately, we discuss the impact on the changes of fault slip potential due to varying angles between the maximum horizontal principal stress and the fault orientation. The main conclusions of this work can be drawn as follows. With the injection rate of 170 m3/h, the maximum excess pore pressure caused by a single geothermal well does not surpass 11 MPa, and it obeys a power decrease distribution with increasing distance from the center of the injection well; its influence scope is no more than 8 km. Continuous water injection strongly changes the stability of those buried faults distributed 2 km within the geothermal wells, and fault-slip potentials of some segmental faults even exceed 85%, corresponding to high unstable risk. Under 50 years of water injection at an injection well, the fault-slip potential of faults with different strikes within 2 km from the injection well increases rapidly with the declining angle among its orientation and the regional maximum horizontal principal stress. This paper's study methodology and associated findings can offer geoscientific justification for the safe exploration and exploitation of deep geothermal resources domestically and internationally. This study can provide a method reference for the location of injection wells and the selection of faults in different orientations in geothermal fields at home and abroad, thus promoting the safe and efficient development and utilization of geothermal resources.

Abstract The chief source of the oilfield scale is the mixing of incompatible waters. This study demonstrated that mixing the reservoir of Mishrif formation (Halfaya oilfield) with six types of injection water sources, including Tigris River water, producing water formation, Gulf seawater, Marshes water, Middle Kirkuk formation water, and Main Outfall Drain water (AL-Masab AL-Aam Channel), leads to the formation of salt crusts that cause the reduction of reservoir rock permeability. According to the Piper diagram, the Mishrif formation water of all extant water samples was of the sodium chloride type (NaCl), except for HF-81, which was between (NaCl) and mix (CaMgCl) type. A geochemical simulation model of water alignment (PHREEQC) was used to simulate this problem, and it revealed the mineral scaling from mixing processes. These minerals precipitate in rock pores and clog them, which then cause damage to the petrophysical properties of the reservoir and prevent the passage of liquids. Results showed that the best water types used for injection are Middle Kirkuk formation water, followed by the general downstream, then Gulf seawater, but treatment before injection is needed. The study of geochemical modeling method can help to better understand scaling issues by efficiently identifying the best injection water from various selected types with the lowest possible cost, which in turn improves oil production.

This research was conducted through the experimentation on the High-Speed Diesel (HSD) Engine to determine the accuracy of the widely used classical empirical models (Eichelberg, Woschni, and Hohenberg) for the estimation of in-cylinder Gas-to-Wall Spatially Averaged Instantaneous Convective Heat Transfer Coefficient (HTC) at part-load conditions with retrofitted Out-Cylinder Water Injection (OWI) System. Absence of the availability of any accuracy determination methodology for HTC estimation models in water injected diesel engines has led to the development of this novel analytical methodology. For this research, in-cylinder pressure was experimentally measured at varying injected water mass flow rates in air intake manifold of the engine. Obtained data was then used for the analysis of multiple thermodynamic parameters, i.e. HTC, Heat Loss to Cylinder Walls (HLCW) and Engine Aggregate Heat Release (EAHR) to study the combustion behaviour of the engine. The Efficiency of Combustion (EOC) was estimated through the proposed comparison method between the Fuel Aggregate Heat Release (FAHR) and EAHR value calculated from each model separately for different Water Injection Rates (WIR). The Degree of Accuracy (DOA) of each HTC model was determined by the EOC value. It was proposed that larger the EOC value, more accurate will be the HTC model. So, through decision-making in developed algorithm, Woschni model appeared as the most accurate model for the determination of HTC for HSD Engine retrofitted with OWI due to its obtained 84% EOC value in comparison with the normal standard of 98% EOC for diesel engines without water injection systems. [ABSTRACT FROM AUTHOR]

In recent years, the drilling technology applied to deep and ultra-deep formations has developed rapidly, but the drilling speed for hard formations is low. Therefore, it is very important to study the drilling methods for deep and hard strata. Particle pulsed jet drilling is a new drilling method based on particle jet impact drilling technology and high-pressure pulsed water jet impact drilling technology. In this paper, the mathematical models of the shear layer amplification coefficient and wave velocity are established based on a similar network theory, and the motion equations of a single particle and particle swarm are established according to the motion of particles in a pulsed jet environment. Then, based on the self-designed particle jet impact rock-breaking experimental platform, the numerical simulation results are compared, analyzed, and verified. The results show that the rock-breaking efficiency increases with the increase in the average velocity of the particle pulsed jet. When the average speed exceeds 160 m/s, the rock-breaking efficiency increases significantly. With the increase in the particle concentration, the rock-breaking efficiency of the particle pulsed jet also increases, but there is an optimal value. When the concentration is too high, the impact of particles on the rock is affected by the collision between particles, and the wear of the drill intensifies. This research is helpful for understanding deep-well drilling-speed-increasing technology and promotes the development and engineering applications of particle jet impact drilling theory. [ABSTRACT FROM AUTHOR]

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

High dip angle reservoirs are affected by gravity, resulting in poor sweep performance at the middle and high parts during waterflooding development. Previous studies have proposed top gas injection development for this type of reservoir, which has provided direction for improving the development effect of such reservoirs. However, current research efforts have mainly focused on the analysis of gas injection effects, rather than delving deeper into the gas injection mechanism and its influencing factors. Furthermore, the research methods adopted thus far have been primarily theoretical and fail to take into account the typical characteristics of high dip reservoirs in actual oilfields. Using a similarity criterion, this study establishes a high-temperature and high-pressure physical simulation device with variable inclination to analyze the impact of gas injection under various water injection conditions on the development of high dip reservoirs. The results suggest that the earlier the injection of water and gas, the slower the overall increase in water cut, and the more distinct the oil wall effect after gas injection, leading to a higher ultimate recovery. In the experiments, earlier injection timing can increase the final recovery rate by 9.59%. In addition, a visualized physical simulation device with an adjustable inclination angle has been established to analyze the sweep performance of high dip reservoirs under various gas injection timings. It is concluded that energy supplement in the early stage of pressure decline in the reservoir resulted in a more uniform movement of the oil-water interface at the bottom and the oil-gas interface at the top, and reduced the probability of water and gas channeling. The overall displacement efficiency is found to be improved with this approach. Earlier injection timing increased sweep efficiency by 5.95% and recovery efficiency by 13.2%, respectively. The injection gas source determined in this study, which is associated gas, is beneficial for low carbon plan and exhibits satisfactory oil recovery. The development of high dip reservoirs through top gas injection in combination with bottom water injection can generate a synergistic effect, which significantly enhances sweep efficiency and ultimate oil recovery. This finding provides theoretical guidance for practical implementation in the field. [ABSTRACT FROM AUTHOR]

Copyright of Atomic Energy Science & Technology is the property of Editorial Board of Atomic Energy Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper presents a streamlined design procedure for water-based noise suppression systems that are applicable to multiple classes of rocket engines. A newly adapted steady quasi-one-dimensional two-phase model is employed to predict the evolution of the exhaust gases interacting with water droplets. Such a model is embedded into a two-step optimization procedure with the objective of finding the most efficient combination of the suppressor operative parameters. This information is then used to design the hardware of the system, which consists in a set of injectors, with the task of producing atomized water jets directed towards the exhaust gases, and a toroidal manifold, with the task of delivering water to the injectors at uniform conditions of pressure and velocity. Finally, the proposed design procedure is applied to a 15 kN thrust class oxygen/methane liquid rocket engine. Technical specifications of the resulting water-based noise suppression system are provided along with a detailed three-dimensional CAD model. [ABSTRACT FROM AUTHOR]

The launch vehicle will experience extreme acoustic environment at lift-off, which will cause the invalidation and destruction of the aerospace equipment, and reducing noise is of great significance for improving launch safety. In this paper, the numerical simulation of gas–liquid two-phase flow and its acoustic field is carried out, and the flow field is simulated by the discrete phase model (DPM), second-order Roe format, Scale-Adaptive Simulation (SAS) and three-dimensional Navier–Stokes. Based on the analysis of the flow field, the acoustic analogy integration method (FW-H) is used to predict the jet noise at the observation position. The influence of the water different injection angles and mass flow rate ratios are studied, and the results show that water injection not only reduces the temperature, velocity and vorticity at the gas–liquid interface, and the temperature at the bottom of the jet deflector, it also significantly reduces the jet noise. The total sound pressure level can be reduced to 6.92 dB by appropriate selection of the water injection angles and water injection mass flow rates. The numerical method established in this paper provides a useful tool for the design and analysis of water injection noise reduction for high-thrust multi-nozzle launch vehicle.

Peat fires can persistently last for an extended period after being ignited, despite rainfall and firefighting efforts. The difficulty of peat fire suppression is mainly due to the smoldering spreading through the subsurface layer. This paper reports laboratory experiments of peat fire suppression by means of water injection directly to the subsurface hotspot. Natural peat samples (from Papua and Jambi, Indonesia) were used in this study. The experimental results show that water injection is more efficient than the water spray technique based on both suppression duration and water usage in extinguishing hotspot areas. The suppression duration of water injection is about half of those of water spray. To fully suppress the fire, Papuan peat required 4.22 ± 0.26 L of water per 1 kg of peat (L/kg-peat), while Jambi peat required 3.81 ± 0.03 L/kg-peat. This study contributes to a better understanding of the suppression dynamic of the water injection technique and proposes its implementation for early peat fire mitigation in the field.

A pressure maintenance strategy is crucial in reservoir management, especially in single-phase oil reservoirs, to keep the reservoir pressure above the bubble point. Water injection is a common way to prevent pressure decline due to production. Water may be injected into oil zone and/or aquifer. Analytical and semi-analytical methods are applied to analyze the reservoir response and pressure alteration during the water injection and pressure maintenance operation. Capacitance- Resistance Model (CRM) is a well-known semi-analytical method to predict oil production by water flooding.In this work, Static Capacitance- Resistance Model (SCRM) in which time constant parameter is unique value in whole matching duration has been applied to estimate water injection in the reservoirs with charging aquifer; in addition to, our aim is analytical investigation of water injection performance in the aquifer zone. As a matter of fact, SCRM has been coupled for the reservoir and aquifer in which SCRM has been written for a reservoir and an aquifer zone as two independent porous medium. Consequently, SCRM has been developed to estimate pressure maintenance performance in the cases of charging aquifer; moreover, new parameter is defined as pressure difference between aquifer and reservoir transition zone (DP) is added to SCRM tuning parameters that can indicate flow and reverse flow between reservoir and aquifer.This parameter is a water saturation-dependent function considered as another tuning parameter. Two synthetic reservoirs were simulated in this work, including homogenous and streak cases with nine spot patterns. The developed SCRM has shown acceptable accuracy, of which 6.1% of total absolute error was obtained for the homogenous case and 7.5% for the streak case.

The efficiency enhancement of argon power cycle engines through theoretical means has been substantiated. However, the escalation of in-cylinder temperatures engenders abnormal combustion phenomena, impeding the augmentation of compression ratios and practical efficiency. This study presents a comprehensive investigation employing experimental and simulation techniques, aiming to extend the boundaries of thermal efficiency and operational capabilities for hydrogen-powered argon cycle engines. The impact of hydrogen direct injection, intake boost, and port water injection is evaluated in conjunction with an argon power cycle hydrogen engine. The hydrogen direct injection, particularly at an engine speed of 1000 rpm, significantly increases the indicated mean effective pressure from 0.39 MPa to 0.72 Mpa, surpassing the performance of the port hydrogen injection. Manipulating the hydrogen direct injection timing results in the formation of a stratified mixture, effectively attenuating the combustion rate, and resolving the issue of excessively rapid hydrogen combustion within an Ar/O2 environment. The implementation of super lean combustion, combined with intake-boosting, achieves a maximum gross indicated thermal efficiency of 57.89%. Furthermore, the port water injection proves to be an effective measure against knock, broadening the operational range of intake-boosted conditions. Notably, the maximum gross indicated thermal efficiency recorded for the port water injection group under intake-boosted conditions reaches 59.35%. [ABSTRACT FROM AUTHOR]

The occurrence of hump instability in pump mode within a pump turbine poses a significant challenge to the safe and stable operation of Pumped Storage Power Plants (PSPP). To achieve more precise numerical simulations, this paper establishes a weakly compressible model of water based on the Tait equation. Using this model, it is discovered that the onset of hump instability is closely linked to an increase in hydraulic losses induced by stalled rotation within the diffuser. Then, a flow control approach employing water injection into the guide vanes of a pump turbine is proposed in order to suppress flow instabilities and optimize the hump region. The findings reveal that the water injection approach can mitigate hydraulic losses, suppress unstable structures, and diminish the pulsation amplitude within the diffuser, ultimately delaying the emergence of the hump region to lower flow mass conditions. This study is helpful in widening the range of the safe and stable operation of pump turbines in pump mode. [ABSTRACT FROM AUTHOR]

The small enhanced technology that synergizes in-cylinder direct injection and turbocharging has good power and fuel economy, and has become a trend in the development of gasoline direct injection engines. However, the enhanced technology has sharply increased the thermal load in the cylinder. It is easy to cause engine knocks, which is currently one of the main limiting factors in improving the performance of direct injection gasoline engines. This paper discusses the influence of direct injection of water into the cylinder on the combustion of gasoline direct injection engines through numerical simulation. The gasoline engine is induced to knock by increasing the compression ratio and advancing the ignition timing. The influence of the water injector (six nozzle holes) layouts (direct water injection in the cylinder) and the water temperatures on the water movement in the cylinder and on the combustion and knock is explored. The in-cylinder water injector and the fuel injector are injected with two nozzles. Results show that when the water injector is arranged in the center of the cylinder head, the water evaporation in the cylinder before ignition is faster. Most of the water is located near the cylinder wall surface, which can reduce the temperature near the wall surface as much as possible and suppress the knock. Therefore, the effect of suppressing knocks is better. The injecting water is advantageous to make the mixed gas distribution uniform and the turbulent kinetic energy high when its temperature is low. [ABSTRACT FROM AUTHOR]

Early water and gas breakthrough is a challenge for developing thin oil rim reservoirs. Secondary recovery methods such as water, gas, simultaneous water and gas (SWAG) and gravity-assisted simultaneous water and gas injection (GASWAG) methods are proven methods for developing thin oil rim reservoirs. Knowledge about a preferred technique is important to minimize cost and enhance performance. In this study, various water and gas injection scenarios applied to thin oil rim reservoirs were evaluated using reservoir simulation studies such that horizontal and vertical wells were used for production and injection respectively. The performance indicators considered include cumulative oil produced, oil production rate, and the onset of water and gas coning. Simulation results showed that injecting gas at the gas-oil contact (case 1) and at the water-oil contact (case 2) were the least favorable in improving oil recovery and in delaying gas coning and gas-cap surface production. SWAG and GASWAG resulted to an increase in production rate by 18.5% and 37.9% respectively in comparison to gas injection. Water injection at water-oil contact (case 3), SWAG and GASWAG augmented reservoir pressure with GASWAG sustaining the force balance within the reservoir much more than other methods during the simulation period. GASWAG technique also resulted to a 28% increase in cumulative oil produced in comparison to SWAG. This is because the GASWAG technique improved sweep efficiency with the downward movement of water and the upward movement of injected gas. Results from this study shows that GASWAG is a preferred method for developing thin oil rim reservoirs and should be adopted. It is however recommended to carry out an optimization study which determines the optimal input parameters for a GASWAG process that maximizes cumulative oil produced and delays water and gas breakthrough. [ABSTRACT FROM AUTHOR]

Carrier-phase direct numerical simulations (DNS) of n-heptane/air combustion with water droplet injection are reported in this paper. The influence of water droplet injection has been analyzed for statistically planar gaseous premixed flames and spray flames where the fuel is supplied in the form of monodisperse fuel droplets. The effects of water injection in both types of flames are compared, including their sensitivities on the initial diameter of water droplets. The simulations are based on an Eulerian-Lagrangian-Lagrangian approach to consider the multi-phase interaction and the simultaneous effects of n-heptane and water droplets. It is shown that the two types of flames are different in terms of several aspects. In particular, the spray flames are characterized by lower temperatures, and their propagation speed is lower than for premixed flames. The main reason for these differences lies in the gaseous equivalence ratio experienced by the reaction zone. For the cases investigated here, where the overall equivalence ratio is unity, the spray combustion occurs under predominantly fuel-lean conditions. Furthermore, the flame temperature is influenced by the initial diameter of water droplets, which affects the strength of thermal expansion within the flame. This in turn influences the evaporation characteristics of both fuel and water droplets due to different residence times within the flame. Although the effects of water droplets on the combustion mode are dependent on the relative position within the spray flame, the net effect is a partial shift from non-premixed to premixed mode. At the same time, the spray combustion occurs under relatively fuel-richer conditions with water injection and these trends appear consistently in laminar and turbulent flows. [ABSTRACT FROM AUTHOR]

The chief source of the oilfield scale is the mixing of incompatible waters. This study demonstrated that mixing the reservoir of Mishrif formation (Halfaya oilfield) with six types of injection water sources, including Tigris River water, producing water formation, Gulf seawater, Marshes water, Middle Kirkuk formation water, and Main Outfall Drain water (AL-Masab AL-Aam Channel), leads to the formation of salt crusts that cause the reduction of reservoir rock permeability. According to the Piper diagram, the Mishrif formation water of all extant water samples was of the sodium chloride type (NaCl), except for HF-81, which was between (NaCl) and mix (CaMgCl) type. A geochemical simulation model of water alignment (PHREEQC) was used to simulate this problem, and it revealed the mineral scaling from mixing processes. These minerals precipitate in rock pores and clog them, which then cause damage to the petrophysical properties of the reservoir and prevent the passage of liquids. Results showed that the best water types used for injection are Middle Kirkuk formation water, followed by the general downstream, then Gulf seawater, but treatment before injection is needed. The study of geochemical modeling method can help to better understand scaling issues by efficiently identifying the best injection water from various selected types with the lowest possible cost, which in turn improves oil production. [ABSTRACT FROM AUTHOR]

Fractured horizontal wells and water-flooding development are effective means to stabilize oil production in low-permeability reservoirs; however, transient pressure behavior analysis based on a single-well testing model ignores the interference effect caused by water-injection wells. With advancements in horizontal drilling technology, multiple-fracture horizontal wells are widely used in tight reservoirs, and researchers have concluded that pressure drops in hydraulic fractures cannot be ignored. In this paper, we present a well testing model that considers the effects of finite-conductivity fractures and the interference of water-injection wells. The analytical solutions were derived based on the source function and superposition principle, and the characteristics of the transient pressure behavior at the bottom hole are analyzed and discussed. The typical pressure curve of our model showed that seven flow regimes exist: wellbore storage stage, transitional flow, first linear flow, fracture interference flow, second linear flow, pseudoradial flow, and interference flow. Furthermore, the results of the sensitivity analysis indicated that the flow regimes are greatly affected by the properties of the fractures and water-injection wells. The length of the fracture mainly affects the transitional flow, first linear flow, fracture interference flow, and second linear flow regimes, whereas the number of fractures predominantly affects the first two stages. The fracture spacing has a significant effect on the fracture interference flow and second linear flow regimes, and the water-injection rate mainly affects the interference flow regime. The well spacing determines when the interference effect occurs. These findings will support more accurate modeling of well production performance considering the impact of water-injection wells. Well test analysis is an effective measure in the process of reservoir development, and it is mainly used to monitor well production performance or estimate the physical parameters of the formation. Currently, multiple-fracture horizontal wells and water-flooding development are widely used in low-permeability reservoirs; however, a single-well test analysis method cannot reflect the reality of communication between production wells and adjacent wells. In this work, we present an interference well testing model that considers the effect of water-injection wells. The transient bottom-hole pressure response under different parameters was studied and analyzed, and the results of this study can be mainly applied in the arrangement of well groups in the development decision stage and adjustments of oil recovery plans in the middle production period. The cases investigated in this study provide several reliable references for engineers in well production management, and may also provide some guidance in further development decisions for oil fields applying multiple-fracture horizontal wells and water flooding. [ABSTRACT FROM AUTHOR]

Copyright of Special Oil & Gas Reservoirs is the property of Special Oil & Gas Reservoirs Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Wall-flow particulate filters are key elements to control particulate matter emissions. The stricter emission standards also for non-road mobility machinery makes this device essential to improve the air quality in the short to medium term. However, their high filtration efficiency brings with it an increase in backpressure. This effect becomes more damaging as particles get accumulated in the filter and in hybrid vehicles where exhaust temperature are lower due to more frequent cold starts. Pre-filter water injection is a proven method to reduce the impact of soot load on the pressure drop avoiding the fuel consumption increase. In this paper, the effect of pre-filter water injections is analysed in engine and flow test rig environments. After verifying the impact of consecutive injection events on fuel consumption, the filter was loaded and divided into quarters. These were studied one at a time in flow test rig to separate soot mal-distribution from water drag effects. A wide range of conditions were tested to assess the change in pressure drop generated by a single injection. With this reference, the soot restructuring pattern was analysed employing optical techniques. These provided evidences of the way the soot fragments got released from the particulate layer and moved towards the inlet channels rear end. Additionally, a closer look into the porous wall micro-structure provided insights explaining the lack of effect on filtration efficiency. These results provide a basis for synergistic removal of vehicle condensates for use in fuel consumption reduction. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Geomechanics is the property of Journal of Geomechanics Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Wet ethanol is a renewable fuel that has great potential to reduce the energy cost of ethanol production and improve the life-cycle carbon footprint of ethanol. The use of wet ethanol in homogeneous charge compression ignition (HCCI) mode can achieve high efficiency with low emission levels. In this context, this study investigates the effects of water-in-ethanol concentration on the performance, emissions, and combustion characteristics of an HCCI engine using water injection and recirculation of all exhaust gasses from a diesel cylinder. Water injection was used to solve the problem that there is no direct method to adjust HCCI combustion. Results showed that water–ethanol blends with higher water content had lower heat release rates and combustion temperatures, which increased the combustion duration. The indicated efficiency deteriorated for ethanol–water blends with high water concentrations. However, the highest indicated efficiency was 39.3% for the blend with 20% water by vol. at 6.0 bar. CO and organic gas emissions tended to increase with late combustion and for blends with higher water content, reaching values of 78.0 and 68.2 g/kWh at 4.0 bar, respectively. On the other hand, the NOX emissions were low, reaching a maximum value of 0.93 g/kWh in the HCCI combustion.

Water injection strategy is considered a promising technique to improve the performance of boosted engine and reduce the NOx emission via the latent heat of water vaporization. Numerous research on water injection has been conducted on in-cylinder and intake port water injection. However, the water injection focusing on the spark ignition (SI) engine exhaust system is still lacking. This study proposed a pre-turbocharger turbine water injection (PTWI) concept to reduce the turbine inlet temperature. This was done so that the stoichiometric engine operation could be achieved at a medium–high load and engine speed without resorting to a fuel enrichment strategy to reduce the exhaust gas temperature. This study aims to investigate the effect of injecting water into the exhaust gas at the pre-turbine of a turbocharged spark ignition engine. This study experimented on a 1.3-L 4-cylinder turbocharged engine to collect engine data for computational fluid dynamics (CFD) baseline model validation. A one-dimensional engine model was then developed based on the 1.6-L 4-cylinder turbocharged engine experiment using AVL BOOST software. The CFD model was used to investigate the effects of water injection pressure, pipe diameter, and water injector location. The CFD results showed that a 50 mm connecting pipe with 4 bar of injection pressure gives the largest reduction in exhaust temperature. The CFD results were then applied to the one-dimensional engine model. The engine model simulation results showed that the fuel consumption could be reduced up to 13% at 4000 rpm during wide-open throttle and 75% engine load. The PTWI is a new approach, but this study has proved the potential of using water injection at the pre-turbine turbocharger to reduce the fuel consumption of a turbocharged SI engine. [ABSTRACT FROM AUTHOR]

Water injection technology has been widely used to prevent and reduce coal caving during roadway excavations in extremely soft and loose coal seams. To evaluate the influence of this technology on the long-term stability of such roadways, a self-developed triaxial creep test system was adopted to obtain the creep behaviors of extremely soft coals with various moisture contents (0.95, 2.30, and 3.26%) at a 0.2 MPa confinement, the creep characteristics and failure modes were compared, the formation condition of a rare secondary creep phenomenon was discussed, and a nonlinear creep model was newly established. The findings showed the following. (1) Extremely soft and fractured coal was characterized by significant rheological features, i.e., a large creep strain, a fast creep rate, and susceptibility to accelerated creep failure. The cumulative strain in natural water state and after 328 h was 2.99%. The steady-state creep rate was as high as 4.89 × 10–5/h, which remained unchanged during the entire steady-state creep stage. These features are markedly different from those of other rocks. (2) When the moisture content increased to 2.3%, the creep strain reached 9.19% within 61 h, and the steady-state creep rate was 4.23 × 10–4/h. After the primary creep, there was an obvious secondary creep process, during which the secondary transient creep stage and secondary steady-state creep stage occurred successively. (3) As the moisture content increased from 0.95% to 3.26%, the ability of the coal sample to resist long-term deformation decreased, i.e., the creep duration before specimen failure decreased dramatically and the creep rate increased markedly; in particular, the steady-state creep rate increased in a power function. (4) A certain water content (~ 2.30%) and confining pressure were required for the occurrence of secondary creep process. (5) The proposed nonlinear creep model could describe the full creep stage perfectly, especially the tertiary creep stage in primary creep process and the entire secondary creep process. [ABSTRACT FROM AUTHOR]

One of the promising ways to increase fuel and modern gas turbine energy efficiency is using cyclic air intercooling between the stages of high- and low-pressure compressors. For intercooling, it is possible to use cooling in the surface heat exchanger and the contact method when water is injected into the compressor air path. In the presented research on the cooling contact method, it is proposed to use a thermopressor that implements the thermo-gas-dynamic compression process, i.e., increasing the airflow pressure by evaporation of the injected liquid in the flow, which moves at near-sonic speed. The thermopressor is a multifunctional contact heat exchanger when using this air-cooling method. This provides efficient high-dispersion liquid spraying after isotherming in the high-pressure compressor, increasing the pressure and decreasing the air temperature in front of the high-pressure compressor, reducing the work on compression. Drops of water injected into the air stream in the thermopressor can significantly affect its characteristics. An increase in the amount of water increases the aerodynamic resistance of the droplets in the stream. Hence, the pressure in the flow parts of the thermopressor can significantly decrease. Therefore, the study aims to experimentally determine the optimal amount of water for water injection in the thermopressor while ensuring a positive increase in the total pressure in the thermopressor under conditions of incomplete evaporation. The experimental results of the low-consumption thermopressor (air consumption up to 0.52 kg/s) characteristics with incomplete liquid evaporation in the flowing part are presented. The research found that the relative water amount to ensure incomplete evaporation in the thermopressor flow part is from 4 to 10% (0.0175–0.0487 kg/s), without significant pressure loss due to the resistance of the dispersed flow. The relative increase in airflow pressure is from 1.01 to 1.03 (5–10 kPa). Based on experimental data, empirical equations were obtained for calculating the relative pressure increase in the thermopressor with evaporation chamber diameters of up to 50 mm (relative flow path length is from 3 to 10 and Mach number is from 0.3 to 0.8). [ABSTRACT FROM AUTHOR]

The influence of water droplet injection on the propagation rate of statistically planar stoichiometric n-heptane-air flames has been analysed based on three-dimensional carrier phase Direct Numerical Simulations for different turbulence intensities and different initially mono-sized droplets. It has been found that most water droplets do not completely evaporate within the flame due to their large latent heat of evaporation for the conditions considered here. Thus, the cooling effect due to the extraction of latent heat during the evaporation of water droplets dominates over the dilution of the concentration of reactants and gives rise to smaller reaction rate of reaction progress variable and thicker flame front than in the corresponding premixed turbulent flame without droplets. These effects (a) strengthen with decreasing droplet size due to higher rate of evaporation for smaller droplets, but (b) weaken with an increase in turbulence intensity. The interaction of water droplets with the flame affects the density-weighted displacement speed through its reaction and molecular diffusion components and the magnitudes of these components remain much greater than the components due to cross-scalar dissipation rate and two-phase coupling. The flame-water droplet interaction for the parameter range considered here acts to reduce the mean density-weighted displacement speed, consumption speed and turbulent flame speed, and this reduction becomes increasingly prominent with decreasing droplet diameter. However, it has been found that the presence of water droplets does not alter the qualitative nature of the strain rate and curvature dependences of both density-weighted displacement speed and consumption speed for the range of parameters considered here, but the correlation strength is altered by the presence of water droplets. [ABSTRACT FROM AUTHOR]

In this study, the potential of gaseous fuels such as hydrogen, methane, and hythane in combination with diesel fuel is assessed in a closed loop thermodynamic framework. An experimental test is conducted with basic diesel fuel and then the model is configured based on the realistic one‐cylinder diesel engine to evaluate the robustness and reliability of the simulation. The model is accurate in terms of in‐cylinder pressure, temperature, and heat release rate within the 3% error band. In principle, three blend cases of diesel50%—methane50%, diesel50%—hydrogen50%, and diesel50%—hythane50% are compared with baseline neat diesel from engine performance to emissions characteristics. For hythane and hydrogen‐involved fuels, the 10% water injection effect is analyzed as well to damp the high flammability and ignition intensity of hydrogen. The findings indicate that the entropy generation in hythane and hydrogen is markedly higher than in diesel case, while water injection can slightly decrease the entropy amount. It is shown that D50H50 has more fuel consumption in higher nozzle diameter (28% at 1 mm hole diameter), while in lower nozzle size range pure diesel fuel consumption dominates. The results revealed that D50Hy40W10 is particularly effective for elevated torque at lower nozzle hole values since the steam contributes toward maximized pressure and the exerted force. The increase of the nozzle number resulted in the CO content increase in the exhaust with the burning temperature reduction. [ABSTRACT FROM AUTHOR]

Due to increasing climate awareness and the introduction of much stricter exhaust emission legislation the internal combustion engine technology faces major challenges. Although the development and state of technology of internal combustion engines generally reached a very high level over the last years those need to be improved even more. Combining water injection with a diesel engine, therefore, seems to be the next logical step in developing a highly efficient drive train for future mobility. To investigate these potentials, a comprehensive evaluation of water injection on the diesel engine was carried out. This study covers >560 individual operating points on the test bench. The tests were carried out on a single-cylinder derived from a Euro 6d four-cylinder passenger car with the port water injection. Furthermore, a detailed pressure trace analysis (PTA) was performed to evaluate various aspects regarding combustion, emission, etc. The results show no significant effects of water injection on the combustion process, but great potential for NOx reduction. It has been shown that with the use of water injection at water-to-fuel rates of 25%, 50%, and 100%, NOx reduction without deterioration of soot levels can be achieved in 62%, 40%, and 20% of the experiments, respectively. Furthermore, water injection in combination with EGR offers additional reduction in NOx emissions. [ABSTRACT FROM AUTHOR]

This study aims to reasonably determine the influence radius of pressure relief of energy-accumulating blasting and water injection in the Liangbei Coal Mine and effectively eliminate local stress concentration and coal seam outburst risk. The change in gas parameters in each test hole before and after energy-accumulating blasting and water injection is determined through ANSYS/LSDYNA numerical simulation, theoretical analysis and calculation, and the application of the gas parameter method in the 32051 heading face of the Liangbei Coal Mine. The influence radius of pressure relief technology of energy-accumulating blasting and water injection in the Liangbei Coal Mine in the direction of energy-accumulating trough is studied, which provides reliable data for the layout parameters of energy-accumulating blasting and water injection hole in the working face of the Liangbei Coal Mine. The experimental results are as follows: 1) The simulation via ANSYS/LSDYNA shows that a blasting cavity is formed by an explosive shock wave in the borehole. The diameter of the blasting cavity in the energy-accumulating direction is 42 cm, which is 10 times the diameter of the energy-accumulating blasting and water injection hole. The diameter of the blasting cavity in the non-energy-accumulating direction is 14 cm, which is 3.3 times the diameter of the energy-accumulating blasting and water injection hole. The stress in the energy-accumulating direction is 2.9 times larger than that in the non-energy-accumulating direction. The crack length in the energy-accumulating direction is 294 cm, and the crack length in the non-energy-accumulating direction is 80 cm. 2) Theoretical analysis and calculation present that the crushing area of shaped charge blasting is 39 cm, the fracture area is 267 cm, and the vibration area is 159 cm. 3) Comparison of the change in gas parameters of each test hole in the field experiment before and after energy-accumulating blasting and water injection indicates that the influence radius of pressure relief in the direction of energy-accumulating trough is 300 cm. 4) The layout of energy-accumulating blasting and water injection in the working face of the Liangbei Coal Mine with 550 cm borehole spacing demonstrates that the verification index of gas drilling decreases, the analytical values (Δh2) decrease from 120–140 Pa to 100–120 Pa, the drilling cutting weight (S) decreases from 3.2 to 4.6 kg/m to 3.0–3.8 kg/m, and stress is released and transferred to deep coal. This study has guiding significance for outburst elimination by local arrangement of energy-gathering blasting and water injection borehole in the working face of the Liangbei Coal Mine.

The extraction of hydrocarbons is associated with obtaining certain amounts of water, which is heavily contaminated with a wide range of chemical compounds that negatively affect the environment. At present, practically the only method of managing extracted reservoir waters is their injection into absorbing horizons. Large changes in parameters (pH, Eh, temperature, etc.) occurring during the extraction and storage of water, as well as the contact of the injected water with reservoir water and rock, may result in the precipitation of secondary sediments. The complexity of the injected water/native water/deposit rock system and the wide range of possible interactions do not always allow for correct interpretation of the processes and their impact on near-well zone permeability. One of the factors which has a decisive influence on dissolution/precipitation is temperature change. Applying analytical data of water with low (W-1) and high (W-2) mineralization, calculations were carried out with the use of PRHEEQC software. Changes in solubility index values were determined at ambient temperature (20 °C) and reservoir temperature (94 °C). The obtained results indicate that with increasing temperature, SI changes for a given chemical compound may run in different directions and take different values, depending on the composition of the injected water. The calculations indicate the possibility of a change in the direction of the reaction from dissolution to precipitation, which may lead to clogging of the near-well zone. Simulations of the injected water's contact with minerals present in the reservoir rock were also carried out. The obtained data indicate that these minerals, in the entire studied temperature range, dissolve in the injected water, but the solubility of anhydrite and dolomite decreases with increasing temperature. If the water is saturated with minerals at low temperature, after heating in the bed, sedimentation and blockage of rock pores may occur, which means there is a reduction in the efficiency of water injection. [ABSTRACT FROM AUTHOR]

• Water injection is highly effective in increasing heat transfer. • "Chamber packing" provides a passive, inexpensive method of increasing heat transfer. • The plethora of studies on simulations and cycles analytics. • Need for experimental validation and long-term performance analysis. • Need for new ways in achieving isothermal compression in refrigeration applications. Compressors can be described as the heart of a vapor compression refrigeration system, circulating the working fluid in the system. Significant benefits can be gained from improving its efficiency since energy consumption is responsible for almost the entire system's power input. An effort has been made to achieve isothermal compression through liquid refrigerant injection or inter-stage cooling in refrigeration systems. In recent years, much effort has been invested into isothermal compression technology for air compressors or compressed air energy storage systems with the rise of renewable energy. This work has explored the advancements made in this area and categorized them to discuss the benefits, limitations, and tradeoffs. Evidently, increasing heat transfer area is a significant aid in improving heat transfer, resulting in better isothermal compression. However, liquid pistons open more avenues for this to be pursued, and therefore, are limited to air compression applications. In addition, water injection proved to be the most effective among the methods. Finally, there is a need for more experimental research on refrigeration applications and the field is still in its infancy. [ABSTRACT FROM AUTHOR]

Peat fires can persistently last for an extended period after being ignited, despite rainfall and firefighting efforts. The difficulty of peat fire suppression is mainly due to the smoldering spreading through the subsurface layer. This paper reports laboratory experiments of peat fire suppression by means of water injection directly to the subsurface hotspot. Natural peat samples (from Papua and Jambi, Indonesia) were used in this study. The experimental results show that water injection is more efficient than the water spray technique based on both suppression duration and water usage in extinguishing hotspot areas. The suppression duration of water injection is about half of those of water spray. To fully suppress the fire, Papuan peat required 4.22 ± 0.26 L of water per 1 kg of peat (L/kg-peat), while Jambi peat required 3.81 ± 0.03 L/kg-peat. This study contributes to a better understanding of the suppression dynamic of the water injection technique and proposes its implementation for early peat fire mitigation in the field. [ABSTRACT FROM AUTHOR]

The launch vehicle will experience extreme acoustic environment at lift-off, which will cause the invalidation and destruction of the aerospace equipment, and reducing noise is of great significance for improving launch safety. In this paper, the numerical simulation of gas–liquid two-phase flow and its acoustic field is carried out, and the flow field is simulated by the discrete phase model (DPM), second-order Roe format, Scale-Adaptive Simulation (SAS) and three-dimensional Navier–Stokes. Based on the analysis of the flow field, the acoustic analogy integration method (FW-H) is used to predict the jet noise at the observation position. The influence of the water different injection angles and mass flow rate ratios are studied, and the results show that water injection not only reduces the temperature, velocity and vorticity at the gas–liquid interface, and the temperature at the bottom of the jet deflector, it also significantly reduces the jet noise. The total sound pressure level can be reduced to 6.92 dB by appropriate selection of the water injection angles and water injection mass flow rates. The numerical method established in this paper provides a useful tool for the design and analysis of water injection noise reduction for high-thrust multi-nozzle launch vehicle. [ABSTRACT FROM AUTHOR]