Hydraulic Energy Research Articles

Considering vegetation flood tolerance in estuary opening decisions

Some estuaries close intermittently when sand is deposited at their mouths and there is insufficient hydraulic energy to breach it. When closed, water levels may rise and flood surrounding land. These floods may adversely impact infrastructure, agriculture and ecosystems that are intolerant of inundation. Consequently, there is often pressure for managers to mechanically open such estuaries. Artificial openings can also cause serious adverse impacts, including mass fish kills, and there may be counter-pressure to leave the estuary closed. Thus, artificial estuary opening is complex and often contested. In response, managers are increasingly using quantitative measures of expected impact to inform and justify their decisions. Here, we demonstrate, using a case study, a tractable approach that quantifies the expected adverse impacts on native estuarine vegetation resulting from inundation. We used structured expert (n = 4) elicitation to gather mortality estimates of 18 prominent estuarine plant taxa under different inundation scenarios (3 salinities, 5 durations). We then used these data to quantify the expected impact on discrete vegetation types, each of which is characterised by one or more of the selected species. Using 1 cm LiDAR-derived elevation data and pre-existing mapping of vegetation types for specific estuaries, we simulated 105 inundation scenarios (7 depths; 3 salinities; 5 durations). From the extent of different vegetation types inundated in the simulations, and the various expected impacts of inundation on each vegetation type, we computed estuary-wide impact scores. These impact scores express the degree of vegetation mortality expected under a given flood scenario for a given estuary. We demonstrated this approach by computing impact scores for 28 artificially opened estuaries in Victoria, Australia. These scores can be used alongside other data (for infrastructure, other biota, etc), to inform mouth-opening decisions. The approach described could be applied to any estuary, provided there is adequate vegetation mapping, elevation data and knowledge or data on the impacts of flooding on the vegetation.

Optimal location of hydraulic energy storage using geographic information systems and multi-criteria analysis

In recent years, society's concern for sustainable development and the environment has grown to the point where renewable energies have become one of the main pillars of this interest. One problem that arises when producing large quantities of renewable energies is the storage and the integration of this production into the grid, which, amongst other possible options, can be solved by means of reversible power plants or pumped storage. For all these reasons, in recent years there has been a growing interest in searching for locations in which to install these types of plants, which have high energy and territorial requirements. This research develops a methodological proposal that allows in the context of Geographic Information Systems to detect and evaluate the most appropriate places to implement this type of facilities in a quasi-automatic way. The methodology proposes a multi-criteria analysis that makes it possible to analyse large extensions of land with ten criteria that cover the energy and territorial requirements that all installations must have, duly weighted. The method assigns each reservoir a location coefficient that reflects the weighting of the ten criteria chosen, so that the value ordered from the highest to the lowest reflects the best to worst location. The proposed methodology is much more consistent than traditional methods because it uses a multi-criteria system and a statistically consistent weighting mechanism, as well as being objective and based on logical criteria. The analysis is general and once the location has been chosen, the corresponding detailed project will be carried out. The proposal is innovative because it involves carrying out the environmental and urban analysis during the decision-making process for the site.

Investigation on motion characteristics of an Anti-pitching Generating WEC (AGWEC) considering the viscous effect

Anti-pitching Generating Wave Energy Converter (AGWEC) uses the relative pitch motion between floating bodies to push the hydraulic energy storage PTO movement, which reduces the relative pitch between floating bodies while generating power. In this paper, based on the CFD method and the potential flow theory with viscosity modification, the motion characteristics of AGWEC in waves are studied. The viscous dissipation term is introduced into the boundary condition of potential flow, and the viscous modified potential flow theory method is established. The Eigenfunction Expansion Matching (EEM) method and Impulse Response Function (IRF) method are used to analyze the motion response of the device in frequency domain and time domain respectively. At the same time, compared with the results of CFD method based on Star-CCM+, the universality of the two methods is proved, and the motion characteristics of the AGWEC based on (non)linear PTO system and the variation law with the relevant parameters are obtained under different floating body axial spacing and wave frequency.

Hydraulic Pressure Ripple Energy Harvesting: Structures, Materials, and Applications

AbstractThe need for wireless condition monitoring and control of hydraulic systems in an autonomous and battery‐free manner is attracting increasing attention in an effort to provide improved sensing functionality, monitoring of system health, and to avoid catastrophic failures. The potential to harvest energy from hydraulic pressure ripples and noise is particularly attractive since they inherently have a high energy intensity, which is associated with the hydraulic mean pressure and flow rate. This paper presents a comprehensive overview of the state of the art in hydraulic pressure energy harvesting, which includes the fundamentals of pressure ripples in hydraulic systems, the choice of electroactive materials and device structures, and the influence of the fluid–mechanical interface. In addition, novel approaches for improving the harvested energy and potential applications for the technology are discussed, and future research directions are proposed and outlined.

The influence of the geometric shape of the symmetrical twisted turbulator on the performance of parabolic solar collector having hybrid nanofluid: Numerical approach using two-phase model

In this investigation, the influence of twisted turbulator and water-based MWCNT-MgO hybrid nanofluid on thermal–hydraulic performance (PEC), energy efficiency (ηn), and exergy efficiency (ηex) of parabolic solar collectors (PSCs) was numerically investigated using the finite volume process. The two-phase nanofluid flows at the Reynolds number (Re) ranging of 10,000–25,000, the RNG k-ε turbulence model is used to model the turbulent flow regime. The nanofluid is modeled by a two-phase mixed model. In addition, the SIMPLEC algorithm was used for simulation. The study is performed for nanoparticles concentrations (φ) of 1% to 3% and pitch ratios (PR) of 0.25, 0.5, 0.75, and 1. Re and φ of MWCNT and MgO nanoparticles were detected to augments (Nuav). It is detected that the values ​​of PEC are more than 1 for all cases. Therefore, it can be concluded that using a twisted turbulator and an enhancement of its PR intensifies PEC. In addition, the results demonstrate that ηn is enhanced and ηex is reduced with the PR of the solar collector having twisted. For case of φ = 3%, as Re increased from 10,000 to 25,000, ηnandηex are enhanced by 45.98% and 31.67% for PR = 1 and 0.25, respectively.

Influence of using innovative turbulators on the exergy and energy efficacy of flat plate solar collector with DWCNTs-TiO2/water nanofluid

This study investigates the effect of using turbulators with innovative geometrie (TIG) and DWCNTs-TiO2/water hybrid nanofluid (HNF) on thermal–hydraulic performance, exergy and energy efficacies of flat plate solar collector (FPSC) using a mixed two-phase model (TPM). Finite volume technique (FVT), SIMLPLEC algorithm and FLUENT software are used. The numerical study is performed for nano-additives concentrations (ϕ) of 1 to 3%, Reynolds numbers (Re) from 7000 to 28000, and PR of 1, 2, 3, and 4 of the proposed TIG in turbulent flow regime. The results show that the average Nusselt number (Nuave) increases by augmenting the Re and ϕ. In addition, at Re = 28,000 and ϕ = 3%, the installation of TIG with PR = 4 within the solar collector (SC) increases the Nuave by 63.46%. In the case of ϕ = 3% and by augmenting the Re from 7000 to 28000, energy and exergy efficacies increase by 22.19% and 23.26% for PR = 4 and PR = 1, respectively.

Characterization of a Commercial Axial Flow PAT Through a Structured Methodology Step-by-Step

A centrifugal pump as a turbine (PAT) is the inverse operation of a conventional pump, which takes advantage of the hydraulic energy of water to convert it into rotational mechanical energy and subsequently into electrical energy, through a generator. The CFD analysis allows predicting the fluid dynamic behavior and calculating the operating characteristic curve of the PAT, thus reducing costs in experimental setups. In the literature, the operation of the turbomachine in pump and turbine mode is evidenced. However, there is no methodology applied in commercial axial flow pumps that exposes a structured step-by-step to carry out the numerical and fluid dynamic analysis. In this study, a novel structured methodology is developed describing the numerical and CFD analysis of a commercial axial flow centrifugal pump, which allows validating the characteristic curve in pump mode and then obtaining the site conditions in turbine mode, for its application in small hydroelectric power plants. As a result, in pump mode, an error of less than 8% is obtained between the manufacturer's curve and the numerical curve. In turbine mode, the best performance is around 73%. The aim is to propose a replicable algorithm in future works that allows the proper analysis in commercial axial flow pumps.

Simulation and Experimental Study on Characteristics of Multiorifice Nozzle in Radial Jet Drilling

The radial jet drilling (RJD) is a key technology to improve the development efficiency of low-permeability oil and gas resources. In order to seek a reasonable hydraulic engineering parameter combination of hydraulic radial jet drilling, to obtain the optimal hydraulic energy distribution, a jet radial horizontal drilling simulation experiment system of the casing windowing is designed. A sequence of experimental investigations focused on engineering parameters of pump displacement, rotating speed, and frequency of high-pressure plunger pump is performed, and the operability and the feasibility of the experiment are verified. To evaluate the maximum drillable length and the self-propelled force of a jet nozzle, a 3D numerical model based on ANSYS-CFX is developed to evaluate the effects of the inlet flow displacement, the flow rates ratio K , and the angle ratio F : B of the forward orifice and backward orifice of the jet nozzle on its maximum drillable length and self-propelled force by sensitivity analysis. Finally, the comparison of numerical simulation results (Ln), mathematical results (Lm), and experiment results (Le) of the maximum drillable length are presented. It is observed that the simulation results are consistent with the experiment results with an average accuracy of 97.07%. Therefore, the proposed numerical model has a good performance in predicting the maximum drillable length of the multiorifice nozzle. The research results can provide theoretical guidance for improving the rock breaking and drilling capability of radial jet drilling technology.

Numerical and Experimental Studies on Hydro-Forming of a Thin Metallic Disc

This paper deals with the hydro-forming of a flat thin metallic disc to achieve a forward domed disc which will be subsequently adopted to manufacture a rupture disc. The plastic deformation induced by the hydraulic energy is numerically simulated through an isotropic hardening plasticity model using a non-linear explicit finite element analysis (FEA). The variation in disc’s central deformation, thickness, equivalent plastic stress and equivalent plastic strain with respect to the applied hydraulic pressure are determined from FEA simulations. The hydro-forming setup is then designed and manufactured, and the metallic disc is experimented under hydro-forming process. The reduction in thickness due to stretching of the thin disc is evaluated from experiment and simulation and a close agreement is found. This research attempt helped in finalizing the hydro-forming fluid pressure, the feasibility and the accuracy of practically achieving the desired geometry of the metallic disc. The near-fixidity effects on abrupt variation in sheet thickness and plastic strain are well captured through simulations which are very difficult to be studied through hydro-forming experiments.

Экспериментальные исследования эффективности прямого преобразования гидравлической энергии в пневматическую

The lack of direct conversion of hydraulic energy into pneumatic energy is considered to be one of the current problems in the sphere of energy conversion technologies. The purpose of this study is to determine the efficiency of the process of converting the initial hydraulic energy into useful pneumatic power at a laboratory experimental installation. As a result of the study, there has been determined the efficiency of direct energy conversion. This technology eliminates four extra stages of conversion. The efficiency of this conversion of hydraulic energy into pneumatic power is approximately 30% higher as compared to traditional technology. The results obtained contribute to the development of the technology of direct conversion of hydraulic to pneumatic energy.

Pilot-scale study of hydraulic retention time and energy consumption in biological treatment of raw municipal wastewater by air micro-nanobubble aeration in different seasons

Pilot-scale study of hydraulic retention time and energy consumption in biological treatment of raw municipal wastewater by air micro-nanobubble aeration in different seasons

INTERACTIONS BETWEEN ABOVE AND BELOW GROUND PLANT STRUCTURES: MECHANISMS AND ECOSYSTEM SERVICES

<List> <ListItem><ItemContent> ● Aboveground to belowground energy transfer. </ItemContent></ListItem> <ListItem><ItemContent> ● Importance of symplasmic nature of sieve tubes. </ItemContent></ListItem> <ListItem><ItemContent> ● Hydraulic, electrical and chemical energy transfer. </ItemContent></ListItem> <ListItem><ItemContent> ● Decreased soil organic C storage over 8000 years. </ItemContent></ListItem></List> Interactions between above and below ground parts of plants can be considered under the (overlapping) categories of energy, material and information. Solar energy powers photosynthesis and transpiration by above ground structures, and drives most water uptake through roots and supplies energy as organic matter to below ground parts, including diazotrophic symbionts and mycorrhizas. Material transfer occurs as water and dissolved soil-derived elements transport up the xylem, and a small fraction of water moving up the xylem with dissolved organic carbon and other solutes down the phloem. The cytosolic nature of sieve tubes accounts for at least some of the cycling of K, Mg and P down the phloem. NO₃^– assimilation of above ground parts requires organic N transport down phloem with, in some cases, organic anions related to shoot acid-base regulation. Long-distance information transfer is related development, biotic and abiotic damage, and above and below ground resource excess and limitation. Information transfer can involve hydraulic, electrical and chemical signaling, with their varying speeds of transmission and information content. Interaction of above and below ground plant parts is an important component of the ecosystem service of storing atmospheric CO₂ as organic C in soil, a process that has decreased since the origin of agriculture.

Simulation of the Hydraulic Behavior of a Bionic-Structure Drip Irrigation Emitter

The bionic structure drip irrigation emitter (BSDE) is a new-type emitter, by which better hydraulic performances can be obtained. In the present work, twenty-five sets of orthogonal test schemes were implemented to analyze the influence of the geometric parameters of the flow channel on the hydraulic characteristics and energy dissipation efficiency of this emitter. Through numerical simulations and verification tests, the flow index and energy dissipation coefficient were obtained. According to the results, the flow index of the BSDE is 0.4757–0.5067. The energy dissipation coefficient under the pressure head of 5–15 m is 584–1701. The verification test has shown that the relative errors among measured values, simulated values and estimated values are less than 3%, which indicates that the flow index can be estimated reliably.

Layout analysis of compressed air and hydraulic energy storage systems for vehicles

The compressed air energy storage system has a better energy density, while the widely used hydraulic one is superior in power performance. Therefore, they are suitable for different hybrid vehicles, which require a comparative study on the performances and vehicle applicability of the broad pressure energy storage system layouts. In this paper, an integrated mathematical model of four basic pressure layouts is presented for characteristic analysis and applicability discussion. Results show that the open volume layout achieves the best power performance with the flow specific power of 13.92 MJ/m3, thus it is suitable for heavy hybrid trucks and mobile machinery. The open mass layout achieves the best energy performance with the energy density of 124.35 MJ/m3, which can be used in light new energy passenger vehicles. And the performance of the closed volume layout is close to the open volume layout with the flow specific power of 9.78 MJ/m3, so it could be applied to middle and light hybrid trucks. This research provides a basis for the hybrid method of pressure energy storage system layouts for vehicles, and could be applied in the design and research of non-electric hybrid vehicles in the near future.

Optimal Braking Torque Distribution of Dual-Motor Front-Rear Individually Driven Electric-Hydraulic Hybrid Powertrain Based on Minimal Energy Loss

Regenerative braking is one of the most important methods for improving energy utilization in electric vehicles. Electric vehicles with front-rear, individually driven configurations exhibit significant potential and flexibility for recovering braking energy. To improve the system’s high-power impact tolerance, a high-power density hydraulic energy storage system can be incorporated to facilitate a full-drive dual-motor electric–hydraulic hybrid (DMEHH) powertrain. The DMEHH system is composed of an independently driven electric–hydraulic hybrid front axle and a purely electric rear axle. In this study, a method for distributing braking torque to minimize energy loss was devised based on the proposed DMEHH powertrain. Power loss models for both the electric and hydraulic subsystems have been developed. Loss minimization control was adapted for the power loss model of the permanent magnet synchronous motors in the powertrain, and the front-rear and front electric–hydraulic torque braking distribution maps were calculated using the energy-loss minimization rule. The application of torque distribution maps resulted in energy losses less than those of the general ideal torque distribution for all braking conditions. The energy loss decreased by 27.2% when the loss minimization control method was used in the WLTC cycle, and decreased by 29.1%, 25.5%, and 21.6% in UDDS, NEDC, and US06 driving cycles, respectively.

Research on Design Method of the Hydraulic Energy Conversion System of Inertial Wave-energy-powered Buoy

Research on Design Method of the Hydraulic Energy Conversion System of Inertial Wave-energy-powered Buoy

Hardware–In–The–Loop Assessment of Robust Fuzzy Control Solutions for Hydroelectric and Wind Turbine Models

The interest towards renewable energy resources is increasing, and in particular it concerns wind and hydro powers, where the key point regards their efficient conversion into electric energy. To this end, control techniques can be used to meet this purpose, especially the ones relying on fuzzy models, due to their capabilities to manage nonlinear dynamic processes working in different conditions, and affected by faults, measurement errors, uncertainty and disturbances. The design methods addressed in this paper were already developed and validated for wind turbine plants, and important results can be achieved from their appropriate design and application to hydroelectric plants. This is the key issue of the paper, which recalls some considerations on the proposed solutions, as well as their validation to these energy conversion systems. Note that works available in the related literature that consider both wind and hydraulic energy conversion systems investigate a limited number of common issues, thus leading to little exchange opportunities and reduced common research aspects. Another important point addressed in the paper is that the proposed control design solutions are able to take into account the different working conditions of these power plants. Moreover, faults, uncertainty, disturbance and model-reality mismatch effects are also considered when analyzing the reliability and robustness features of the derived control schemes. To this end, proper hardware-in-the-loop tools are considered to verify and validate the developed control schemes in more realistic environments.

Mounting position effect on hydraulic cylinder subjected to impulse force

Hydraulic cylinders are commonly used in mechanical systems to convert hydraulic energy into mechanical energy to realise linear motion where high forces and robust operation is required. They are used in truck mounted guns to support the outriggers or spades which transmitted the impulse forces resulting from firing to the ground to protect the truck suspension and chassis. The total stiffness of a hydraulic cylinder and the transmit stress waves are affected by its mounting direction. In this paper the effect of mounting position of cylinders subjected to impulse force from firing was studied. It was found that the direction of mounting plays a significant rule on stress waves effects acting on both cylinder rod and cylinder barrel when subjected to impulse force. Results show that mounting position of cylinder barrel load case is better than mounting position of rod load case to withstand the stress waves.

Monthly Electricity Generatıon Forecast in Solar Power Plants with LSTM

Today, with the intensive use of electrical devices, the need for electricity has increased. Fossil fuels are generally used to meet this need. However, considering the damage caused by fossil fuels to the environment, governments make various incentives for renewable energy sources. The incentives of countries for solar power plants are quite large. Recently, there are many investors who want to build solar power plants. The sunshine duration of our country is quite high. And the fact that the climatic conditions are efficient for the generation of electricity attracts many investors. However, the installation of these power plants is quite costly. It is possible to predict the amortization periods of these costs with the ever-developing artificial intelligence technology. In this study, the energy data to be produced in the future is estimated by using real solar power plant data with machine learning algorithms. Data, take from solar power plants owned by Humartaş Energy company. In the study, predictions and analyses were made using the LSTM (Long Short-Term Memory) method, which is one of the artificial neural networks. The error rate of the study between 1% and 15%. It is foreseen that studies will also be implemented with other renewable energy sources such as wind, geothermal, hydraulic energy data in the coming stages.

Measuring system for monitoring the polydimensional deformation of superstructures of bridges and over-bridges improvement of volume hydraulic drive construction and road machines using flow shareholders

Due to its advantages, the hydraulic drive is widely used in road construction machines. Depending on its design, the share of the hydraulic drive, which is the most expensive unit of a road construction machine, accounts for thirty to eighty percent of all failures. Reliable hydraulic drive, provides, to a large extent, the reliability of the whole machine and the efficiency of the construction organization as a whole. The efficiency of the hydraulic drive of construction machines, and, as a consequence, the machines themselves, is ensured by a set of measures, among which the most important is the quality design, manufacture and operation, combined into a single structural system. Depending on the quality of cleaning of the working fluid, the service life of hydraulic machines can be increased or decreased several times. Accumulation of pollutants in the hydraulic drive, the hardness of which is significantly higher than the hardness of metals, causes rapid wear of the surfaces of hydraulic units and the service life is rapidly reduced. Cavitation in the pump is accompanied by a pulsation of fluid pressure and noise. These pulsations are due to the return flow of fluid from the discharge cavity of the pump, which is accompanied by hydraulic shocks and as a result of alternating shocks, a pressure pulsation in the discharge line of the pump. The amplitude of these pulsations can, under known conditions, reach a value that causes the destruction of the pump. The possibility of cavitation can be reduced by rational choice of modes of operation of the hydraulic system and the correct design of its units, but this phenomenon can be completely eliminated only by using auxiliary pumping pumps, as well as increasing the pressure in the suction line of the pump. On the basis of the analysis of perspective directions of improvement of the hydraulic drive of the excavator the following improved scheme of it is developed. Usually only high-flow hydraulic motors can be used in flow dividers. But in our case it is necessary that the device had, first of all, small mechanical losses and small cost, and accuracy of division of working liquid which follows on filters can be small. In the volume flow divider, hydraulic motors are used: gear, piston, vane, screw, roller. The simplest dividers of volume type are paired (connected by shafts) hydraulic motors of lamellar (vane) and roller types. Hydraulic motors in this scheme are flow measuring devices (dispensers), which supply for one revolution the volume of liquid, equal without taking into account the leaks in the hydraulic motor, its working volume. The use of a flow divider as a source of hydraulic energy makes it possible to improve the hydraulic drive by combining in a single system the purification of the working fluid and the ejector feed of the pump. The most promising, in terms of cost, are flow dividers based on vane and rotary hydraulic motors..