Hydraulic Energy Research Articles

Seasonally stable wetted width elucidates freshwater mussel species richness and endangered species presence: implications for T&E management programs and stream restoration design

Centuries of beaver extirpation, deforestation, and other anthropogenic impacts have disconnected North American rivers from their floodplains and concentrated more hydraulic energy within their channels, degrading aquatic habitat and making the streambed more prone to erosion. Rivers naturally adjust via systematic downcutting, bank erosion, channel widening, bar building, and the gradual recovery of geomorphic equilibrium with well‐connected benches that dissipate hydraulic energy and restore a more natural streambed disturbance regime. The life histories of two endangered freshwater mussels, the fanshell (Cyprogenia stegaria) and snuffbox (Epioblasma triquetra), suggest they have evolved to and depend on the natural disturbance regime. Young juveniles excyst from their host fish in early summer, burrow into the top few millimeters of the streambed, and then need ca. 3 months of streambed stability prior to growing large enough to be less vulnerable to streambed mobilization. We propose a conceptual model that suggests a potential prerequisite to supporting fanshell and snuffbox populations is a geomorphically recovering (i.e. at least one stable bank and a wide enough channel corridor for at least partially vegetated bars/benches) or recovered (i.e. stable banks and vegetated benches) channel and floodplain corridor that sufficiently dissipates its hydraulic energy to maintain seasonal streambed stability during typical (non‐hurricane) summer/autumns. To explore this conceptual model, we conducted mussel and geomorphic surveys in a reach of the Rolling Fork River that spanned a range of channel conditions from chronically failing streambanks to a geomorphically recovered channel with wide, vegetated benches. Our analyses documented increasing mussel species richness, including the presence of the endangered fanshell or snuffbox, with increasing width of seasonally stable streambed habitat.

Hydroelectric energy conversion of waste flows through hydroelectronic drag

Hydraulic energy is a key component of the global energy mix, yet there exists no practical way of harvesting it at small scales, from flows with low Reynolds number. This has triggered a search for alternative hydroelectric conversion methodologies, leading to unconventional proposals based on droplet triboelectricity, water evaporation, osmotic energy, or flow-induced ionic Coulomb drag. Yet, these approaches systematically rely on ions as intermediate charge carriers, limiting the achievable power density. Here, we predict that the kinetic energy of small-scale "waste" flows can be directly and efficiently converted into electricity thanks to the hydroelectronic drag effect, by which an ion-free liquid induces an electronic current in the solid wall along which it flows. This effect originates in the fluctuation-induced coupling between fluid motion and electron transport. We develop a nonequilibrium thermodynamic formalism to assess the efficiency of such hydroelectric energy conversion, dubbed hydronic energy. We find that hydronic energy conversion is analogous to thermoelectricity, with the efficiency being controlled by a dimensionless figure of merit. However, in contrast to its thermoelectric analogue, this figure of merit combines independently tunable parameters of the solid and the liquid, and can thus significantly exceed unity. Our findings suggest strategies for blue energy harvesting without electrochemistry, and for waste flow mitigation in membrane-based filtration processes.

Techno-economic comparison between commercial energy recovery devices in complex Water Distribution Networks

Water Distribution Networks (WDN) proved to be viable for the exploitation of throttling hydraulic energy. Researchers often focused their attention on the study of Pumps as Turbines (PaTs) for WDNs without considering other solutions. Actually, PaTs are not the only machines that can be employed. Indeed, other solutions exists, e.g. Cross-Flow Turbines, and commercially available Energy Harvesting Control Valves. The novelty of this study regards the selection, for each node, of the best technology among these machines rather than choosing only among PaTs, in order to help the water utilities in the techno-economic decision processes. Regarding PaTs, the authors have updated and integrated PaT-ID, their proprietary decision making tool. A complex real WDN has been used as a case study, characterized by 8 reservoirs and 16 Pressure Reducing Valves (PRVs) installed to balance the network and to reduce water leakages. Although all the three considered type of devices show at least 40% of recovered available energy within the WDN, the best solution form an energy point of view not always could be feasible from an economic point of view.

Dynamic Modelling and Analysis of a Hydraulic Energy Storage Based Hybrid Power Transmission for Wind Turbine

Dynamic Modelling and Analysis of a Hydraulic Energy Storage Based Hybrid Power Transmission for Wind Turbine

Simulation and Experimental Research on a New Symmetrical Hydraulic Piezoelectric Energy Harvester

This study introduces a new symmetrical hydraulic piezoelectric energy harvester. By integrating theoretical analysis, simulation, and empirical testing, the research delves into the energy‐harvesting potential of monolithic single‐side output, monolithic two‐side parallel‐connected output, stacked one‐side parallel‐connected output, and stacked two‐side parallel‐connected output under varying parameter configurations. Additionally, it elucidates the energy dissipation occurring during the energy‐harvesting process of stacked piezoelectric disks. It has been observed that the primary determinant of voltage is the amplitude of pulsation, not the static pressure. Concurrently, the study also addresses the consistency of power generation between multiple channels. A study is made on whether there is a proportional relationship between single‐channel power generation and multi‐channel power generation. The root mean square (RMS) voltage of each connection sharply rises with resistance from 2 to 100 KΩ. It is found that the performance of parallel connection of monolithic piezoelectric disk is better than that of other connection methods. At 3 MPa and 100 Hz, the optimal resistance is 16 KΩ, yielding a maximum average power of 1155.63 μW and an optimal power density of 1.774 μW (bar mm3)−1. Consequently, the research offers a novel approach to addressing the issue of sustainable energy supply for low‐power electronic devices and sensors.

Prototyping disruptive self-sufficiency power machines composed by cascaded power units based on thermo-hydraulic actuators

This research focuses on developing a prototype for a disruptive Self-Sustaining Power Machine (SSPM) that consists of cascaded power units (PUs). Each PU integrates thermo-mechanical and thermo-hydraulic actuators to drive hydraulic pumps connected to generators. The prototype's design leverages two thermal cycle types, sVsVs and VsVs, which enable self-sustaining operations by employing several strategic capabilities that challenge the limitations of second-kind perpetual motion machines (PMMs). Therefore, key capabilities include: 1- Performing useful mechanical work through the expansion and contraction of the Thermal Working Fluid (TWF) by adding and removing heat. 2- Utilizing recovered heat through potential superposition techniques, thereby upgrading the heat to a higher grade, which enhances heat recovery strategies. 3- Designing an efficient energy transfer chain from thermal to electrical energy via thermo-mechanical or thermo-hydraulic actuators, a hydraulic energy drive system, and conversion from hydraulic to electrical energy. 4- Configuring the system to achieve more useful work than the heat added to the initial PU downstream. Two main prototype types are proposed to demonstrate these proposed capabilities: 1- Continuous motion using the sVsVs thermal cycle, with volumetric reservoirs for thermal working fluids (TWF) located outside the thermo-mechanical or thermo-hydraulic actuators. 2- Discontinuous motion using the VsVs thermal cycle, with volumetric reservoirs for TWF located inside the active volume of the thermo-mechanical or thermo-hydraulic actuators. The prototypes were evaluated through case studies using air and helium as real TWFs. Results indicate that the SSPM composed of five cascaded PUs operating on an sVsVs cycle achieved a global efficiency of 149.6% (SSI of 49.6%) with helium and 126% (SSI of 26%) with air. In contrast, the VsVs cycle yielded a global efficiency of 183% (SSI of 83%) with helium and 133% (SSI of 33%) with air

Study on the Equivalent Density Tool and Depressurisation Mechanism of Suction-Type Depressurisation Cycle

In order to further regulate equivalent circulating density (ECD), a novel downhole apparatus for reducing circulating pressure in high-temperature and high-pressure wells, the suction-type ECD reduction tool, was devised. The utilisation of this tool enables the bottomhole pressure of the equivalent circulating density to be attained in close proximity to its hydrostatic pressure, thereby facilitating the attainment of deeper drilling depths. The tool is composed primarily of a screw motor, scroll blades, annular seals, universal joints, and drilling columns. The tool operates by utilising the suction effect and hydraulic energy extracted from the circulating fluid by the screw motor, which is then converted into mechanical energy to create suction and enhance the flow energy of the drilling fluid within the annulus at the bottom of the well, thereby reducing the equivalent circulating density. Furthermore, based on ANSYS-FLUENT analysis simulations, the alteration of pressure drop characteristics in response to varying drilling fluid densities, displacements, and tool sizes was modelled. The simulation results demonstrate that the pressure drop effect is 1.0 MPa when the drilling fluid density is 1.2 g/cm3, 1.7 MPa when the drilling fluid density is 1.5 g/cm3, and 1.9 MPa when the drilling fluid density is 1.8 g/cm3. A pressure drop of approximately 2.3 MPa was observed when the drilling fluid density was 2.0 g/cm3. The maximum pressure drop is achievable with a flow rate ranging from 1500 to 2500 L/min. A maximum pressure drop of 2.3 MPa is observed when the flow rate is within the range of 1500 to 2500 L/min. Two distinct viscosity values (0.02 and 0.06 kg/(m·s)) were employed to assess the impact of viscosity on pressure drop characteristics in a suction-type ECD tool. The results demonstrated that the pressure drop remained largely unaltered, indicating that viscosity had minimal influence on this parameter. The flow rate emerged as the primary factor affecting pressure drop, with viscosity exerting a relatively minor effect.

Computational Fluid Dynamics Study on Bottom-Hole Multiphase Flow Fields Formed by Polycrystalline Diamond Compact Drill Bits in Foam Drilling

High-temperature geothermal wells frequently employ foam drilling fluids and Polycrystalline Diamond Compact (PDC) drill bits. Understanding the bottom-hole flow field of PDC drill bits in foam drilling is essential for accurately analyzing their hydraulic structure design. Based on computational fluid dynamics (CFD) and multiphase flow theory, this paper establishes a numerical simulation technique for gas-liquid-solid multiphase flow in foam drilling with PDC drill bits, combined with a qualitative and quantitative hydraulic structure evaluation method. This method is applied to simulate the bottom-hole flow field of a six-blade PDC drill bit. The results show that the flow velocity of the air phase in foam drilling fluid is generally higher than that of the water phase. Some blades’ cutting teeth exhibit poor cleaning and cooling effects, with individual cutting teeth showing signs of erosion damage and cuttings cross-flow between channels. To address these issues, optimizing the nozzle spray angle and channel design is necessary to improve hydraulic energy distribution, enhance drilling efficiency, and extend drill bit life. This study provides new ideas and methods for developing geothermal drilling technology in the numerical simulation of a gas-liquid-solid three-phase flow field. Additionally, the combined qualitative and quantitative evaluation method offers new insights and approaches for research and practice in drilling engineering.

‘Our Path from the Land’: Environmental Displacement and Anthropocenic Futures in Chinese Short Fiction

ABSTRACT As global warming imperils resource production and international security, nations around the world have been urged to develop sustainable, resilient infrastructure to curb and mitigate the worst effects of climate change. China has raced ahead in this process, commissioning hydraulic and green energy megaprojects to maintain the nation’s economic stability in the face of environmental precarity. However, these developments have come with a high cost for Chinese citizens, permanently forcing millions from their homes. Literary and cultural responses to displacement from Chinese authors abound, dividedly praising and critiquing the state’s technocratic, growth-centric response to climate change challenges. This article compares two such short stories, namely Liu Cixin’s ‘Yuanyuan’s Bubbles’ (2015) and Wang Ping’s ‘Maverick’ (2007) to consider the tensions surrounding green infrastructural transitions in contemporary China, where, on both sides of the polemic, the environmental migrant functions as a symbol of the nation’s uncertain social futurity.

Feasibility study of geothermal assisted energy storage using hydraulic fracturing

Similar to wind and solar energy, geothermal energy, as a renewable energy source that is widely distributed, abundant, green, and low-carbon, has substantial potential. In this study, we introduce and validate the feasibility of a novel approach that employs hydraulic fracturing techniques to store electrical power in hydraulic fractures, while simultaneously extracting geothermal energy from the strata. The primary advantage of this methodology is its dual functionality (i.e., storing energy while harvesting heat). This approach outperforms conventional energy storage methods in terms of efficiency, in which the total energy storage efficiency is far greater than 1. Our study analyzed the factors influencing energy and efficiency, as well as the variations in energy and efficiency under long-term energy storage conditions. This study also provides a theoretical basis for optimizing the design of hydraulic fracturing energy storage assisted by geothermal energy.

An Assessment of the Embedding of Francis Turbines for Pumped Hydraulic Energy Storage

In this paper, analyses of Francis turbine failures for powerful Pumped Hydraulic Energy Storage (PHES) are conducted. The structure is part of PHES Chaira, Bulgaria (HA4—Hydro-Aggregate 4). The aim of the study is to assess the structure-to-concrete embedding to determine the possible causes of damage and destruction of the HA4 Francis spiral casing units. The embedding methods that have been applied in practice for decades are discussed and compared to those used for HA4. A virtual prototype is built based on the finite-element method to clarify the influence of workloads under the generator mode. The stages of the simulation include structural analysis of the spiral casing and concrete under load in generator mode, as well as structural analysis of the spiral casing under loads in generator mode without concrete. Both simulations are of major importance. Since the failure of the surface between the turbine, the spiral casing, and the concrete is observed, the effect of the growing contact gap (no contact) is analyzed. The stresses, strains, and displacements of the turbine units are simulated, followed by an analysis for reliability. The conclusions reveal the possible reasons for cracks and destruction in the main elements of the structure.

Fuel-Saving Solution for Forklifts Using Hydraulic Energy Storage and Regeneration Device Cluster Additionally Installed

Fuel-Saving Solution for Forklifts Using Hydraulic Energy Storage and Regeneration Device Cluster Additionally Installed

Nonlinear dynamics analysis of hydraulic turbochargers in reverse osmosis desalination plants

The hydraulic turbocharger plays a vital role in harnessing the energy stored in brine within reverse osmosis desalination plants. To optimize the efficiency and durability of this equipment, it is crucial to develop accurate dynamic models of the turbocharger rotor. An improved understanding of rotor dynamics enables the integration of innovative technologies such as Hydraulic Energy Management Integration, effectively enhancing efficiencies in systems characterized by small capacities and high rotational speeds. This study presents a dynamic modeling methodology for the hydraulic turbocharger. The analysis involves approximating the turbocharger rotor with an equivalent finite element shaft line model. Verification of the model’s natural frequency is conducted using three-dimensional finite element analysis, employing the ANSYS modal analysis module. Computational fluid dynamics is employed to evaluate the fluid forces, while the Reynolds equation is utilized to assess the journal bearing forces. The resulting model is employed to investigate the nonlinear dynamics of the rotor, examining the impact of various system parameters, including rotational speed, unbalance forces, and shaft geometrical parameters. The results highlight the significance of balancing the turbine and pump disks for optimal performance. Furthermore, the research demonstrates that increasing the shaft length reduces the rotor’s threshold speed, while increasing the shaft diameter initially raises the threshold speed until it reaches a critical value. Beyond this critical value, further increases in shaft diameter lead to a decrease in the threshold speed.

Impact and Technical Solutions of Hydrodynamic and Thermodynamic Processes in Liquefied Natural Gas Regasification Process

Transporting natural gas in liquid form increases opportunities for storage and export worldwide, thus making transportation more sustainable. However, liquefied natural gas (LNG) is in an unsteady state, leading to LNG conversion to the gas state occurring throughout the storage, loading, unloading, and transportation processes. To observe the transition of LNG to natural gas, mathematical models are developed to monitor technical parameters. This research analyses a floating storage and regasification unit for and adopts a mathematical model of the LNG regasification system, aiming for improved observation of hydrodynamic, dynamic, and thermo-physical properties. The complex mathematical model of the system was implemented using the Fortran programming language and MATLAB R28a. From the investigation of the total LNG regasification system, it could be concluded that increasing the outlet pressure of the system results in a decrease in the velocity of LNG. It was found that the total hydraulic energy losses of the total LNG regasification system were approximately 41.3 kW (with outlet pressure of 2 MPa), 12.75 kW (with outlet pressure of 5 MPa), and 4.24 kW (with outlet pressure of 7 MPa).

Research on the Flow Characteristics in the Gap of a Variable-Speed Pump-Turbine in Pump Mode

A variable-speed pump-turbine is the core component of a hydraulic storage and energy generation station. When the pump-turbine operates at a constant speed, its response to the power grid frequency is poor. In order to improve the hydraulic efficiency of the pumped storage unit, variable-speed units are used. However, there has been no numerical study on the effect of the rotational flow characteristics within the gap of a variable-speed pump-turbine. This paper calculates the flow characteristics within the gap of a variable-speed pump-turbine under three typical pump modes (maximum head minimum flow condition, minimum head maximum flow condition, and maximum speed condition). The research results indicate that the rotational speed significantly affects the pressure distribution, velocity distribution, and turbulent kinetic energy distribution within the crown and band gaps. The higher the speed, the larger the area of the high-pressure region before the runner inlet compared to other operating conditions, and similarly, the low-pressure area after the runner outlet is also larger than in other operating conditions. The change in speed mainly affects the internal flow field of the crown gap, with the most noticeable changes occurring in the pressure and flow velocity at the inlet and outlet of the crown gap. There is a clear trend of pressure drop and velocity increase within the gap as the speed increases. However, with the increase in speed, the pressure distribution and flow velocity within the band gap remain almost the same. In addition to speed changes, it is observed that the pressure within the gap and the flow velocity within the passages are also related to the head, especially in the condition of maximum head, where this relationship becomes more noticeable.

Turbine selection for hydraulic energy recovery in the Yuribia dam aqueduct

The recuperation of hydraulic energy in aqueducts is based on utilizing the energy dissipated by hydraulic devices aimed at regulating the flow or pressure within the system, in addition to fulfilling their primary purpose. This paper presents the methodology for the selection of a turbine coupled to a generator for the recovery of hydraulic energy in the aqueduct of the Yuribia dam situated in the state of Veracruz, Mexico. The results of system modeling, simulation, and calculation of the generated energy are presented.

Optimal energy distribution in hydraulic hammer forging for minimizing total energy and forging load

Hammer forging is an important manufacturing technology in heavy industry to produce high stiffness product. Forging using mechanical press produces the product by controlling the distance between dies whereas the hydraulic hammer forging utilizes the energy given by the sum of hydraulic energy and potential energy of die, and the product is then produced through several blows. The energy at each blow is conventionally determined through the trial-and-error method. The process to produce the product is simple and the response of hammer foundations and anvil is mainly discussed in the literature, but the optimal energy distribution to successfully produce the product is rarely discussed. In this paper, the optimal energy distribution in hydraulic hammer forging is determined using numerical simulation coupled with design optimization technique. To determine the optimal energy distribution through the process, multi-objective design optimization for minimizing both the total energy and the maximum forging load is performed. High dimensional accuracy is generally required in the forged product, and the underfill is handled as the design constraint. The numerical simulation in hydraulic hammer forging is computationally so expensive that sequential approximate optimization that response surface is repeatedly constructed and optimized is adopted to identify the pareto-frontier between the total energy and the maximum forging load. It is clarified through the numerical result that the total energy is drastically reduced without the underfill in comparison with the conventional one. The experiment is also conducted to examine the proposed approach.

Исследование математической модели объемного гидропривода с релейным управлением применительно к грузовой лебедке крана

The known variants of volumetric hydraulic drives of lifting and technological mechanisms are considered and analyzed. The areas of application of pumping and accumulator hydraulic drives, with various types of regulation, and options for their implementation as drives of a cargo winch of a bridge crane are considered. It is shown that the operation of the volumetric hydraulic drives of the cargo winch, along with volumetric and throttle control, can be performed by a relay method. It is noted that the cyclical operation of lifting mechanisms during lifting and lowering of cargo allows for mechanical and hydraulic energy recovery within the working cycle, which is a promising way to significantly increase the efficiency of their work. The analysis of the existing designs of hydraulic drives of technological machines, allowing to recover the potential energy of working bodies with cargo, is carried out. It is proposed as an alternative to the known hydraulic drives of the cargo winch of the bridge crane, a hydraulic drive with relay control. The efficiency of such a drive is shown, according to the indicators of the nominal pressure utilization coefficient and the energy intensity of the working fluid, in the case of the implementation of mechanical and hydraulic energy recovery in the working cycle in it. The mechanical and hydraulic circuits of such a drive are examined. An algorithm of mathematical model of its operation with consideration of different phases of cargo movement is proposed and its investigation is carried out. The possibility of fulfilling the safety conditions of operation of a hydraulic drive with relay control, in terms of ensuring the requirements for the uniformity of cargo movement, is analyzed.

Does the Type of Renewable Energy Matter for Economic Growth? An Empirical Investigation using Panel Data from 212 Countries between 1965 and 2021

This paper analyzes the effects of different sources of renewable energy on economic growth utilizing a panel of 212 countries between 1965-2021. The focus lies on five renewable energy sources: solar, wind, hydraulic, biofuel, and geothermal. Findings reveal that geothermal and hydraulic energies impact positively economic growth, while solar, wind, and biofuel energies negatively impact it. Consequently, the study suggests that policymakers should prioritize the development and investment in hydraulic and geothermal energy, while reconsidering support for solar, wind, and biofuel sources. The efficiency and cost of each energy type may vary based on factors such as location, technology, and available resources.

The Power Circuit of Mechanical Damping Device for Cooling System of 50 kW Pulse Diesel Generator

Diesel generators have advantages such as high reliability, superior economic performance, and a wide range of applications. However, its working environment is relatively sealed, and it is difficult for the internal heat of the motor to transfer to the outside. Prolonged high temperatures can affect the operational performance of the motor and even cause danger. Therefore, it is necessary to design a reasonable cooling system to ensure its efficient operation within the safe working temperature. The water-cooled cooling system has good heat dissipation performance, consisting of components such as a water pump, radiator, fan, water tank, and temperature controller. By precisely controlling the water flow rate and wind speed, effective control of the internal temperature of the generator is achieved, extending the service life of the equipment. This article studies the power circuit of the mechanical damping device in the cooling system of a 50kW pulse diesel generator, develops heat transfer and hydraulic energy circuits, and constructs the frequency response of the circuit. As the water quality increases in the circuit, the amplitude decreases at low frequencies (less than 4 rad/s) and frequencies close to 10 rad/s, and the amplitude aligns. For one parameter variable, the optimal frequency is 3-4 rad/s.