Hydraulic Device Research Articles

APPLİCATİON OF THE WORKİNG FLUİD İN THE HYDRAULİC TRANSMİSSİON

Issues related to the determination of the steady-state temperature of the hydraulic systems of volume hydraulic devices for the stability of the output lane are of great importance. Therefore, it is necessary to know the time for the hydraulic system of the volume hydraulic actuator to reach a stable temperature regime. The transition mode is a complex function of a large number of variables, and at the same time it is necessary that it should be as short as possible, which will save both power consumption and idle operating time of the installation. First of all, the parameters that influence the dynamics of the flow processes of volumetric hydraulic machines are their pressure, hydraulic system, initial temperature of hydraulic equipment, ambient temperature, availability of cooling devices and, as already mentioned above, hydropower coefficients. In this regard, the topic of this paper is relevant, and even a partial, qualitative study of the dynamics of temperature fields can be useful for understanding the physical state of what is happening in hydraulic machines. The hydraulic machine has a high special power for a single mass (7.36-8.83 kW per 1 kg of mass), and even relatively small relative energy losses lead to significant prices for a special heat flux g > 600 kVt/m2. Due to local overheating of individual sections of the surface of the hydraulic machine, a certain part of the heat in unsteady mode is spent on changing the temperature of the housing and its individual components and parts. This article examines the dynamics of the temperature field during operation and extinguishing using the example of the most used gear pump for a positive-position hydraulic machine. Keywords: hydraulic systems, hydraulic equipment, temperature, dynamic mode, working fluid.

Influence of fracture parameters on hydraulic shear seepage characteristics of granite

To reveal the influence mechanism of different fracture parameters on the permeability characteristics of hot dry rock after hydraulic shear. The self-made high temperature true triaxial hydraulic shear test device and rock roughness profile tester were used. The granite in Daqing area of Songliao Basin is taken as the research object. The prefabricated fractured granite is subjected to high-temperature treatment. The geological characteristics of different geothermal reservoirs are simulated by changing the three-dimensional stress. The roughness coefficient of the fracture surface is used to characterize the variation characteristics of fracture before and after hydraulic shear. The influence of different fracture angles and roughness on the permeability of granite after hydraulic shear was tested. Combined with numerical simulation, the relationship between fracture parameters and geothermal mining performance is analyzed. The results show that the maximum water injection pressure of hydraulic shear decreases with the increase of fracture angle by quadratic polynomial law and increases with the increase of fracture roughness by quadratic polynomial law. The variation of fracture surface roughness coefficient fluctuates within 0–2 with the increase of volume stress before and after hydraulic shearing. The variation of fracture surface roughness coefficient increases linearly with the increase of water injection flow rate and increases with the increase of water injection time, and there is a fluctuation range of 0.38–0.44. After hydraulic shear, the permeability of granite increases first and then decreases with the increase of fracture angle. When the fracture angle is 15°, the permeability has the maximum value. The permeability increases with the increase of fracture surface roughness. The numerical simulation results show that the high fracture opening (15 mm), high fracture number, and high fracture penetration performance significantly improve the geothermal mining efficiency.

A Soft Robotic Actuator System for In Vivo Modeling of Normal Pressure Hydrocephalus.

The intracranial pressure (ICP) affects the dynamics of cerebrospinal fluid (CSF) and its waveform contains information that is of clinical importance in medical conditions such as hydrocephalus. Active manipulation of the ICP waveform could enable the investigation of pathophysiological processes altering CSF dynamics and driving hydrocephalus. A soft robotic actuator system for intracranial pulse pressure amplification was developed to model normal pressure hydrocephalus in vivo. Different end actuators were designed for intraventricular implantation and manufactured by applying cyclic tensile loading on soft rubber tubing. Their mechanical properties were investigated, and the type that achieved the greatest pulse pressure amplification in an in vitro simulator of CSF dynamics was selected for application in vivo. A hydraulic actuation device based on a linear voice coil motor was developed to enable automated and fast operation of the end actuators. The combined system was validated in an acute ovine pilot in vivo study. in vitro results show that variations in the used materials and manufacturing settings altered the end actuator's dynamic properties, such as the pressure-volume characteristics. In the in vivo model, a cardiac-gated actuation volume of 0.125 mL at a heart rate of 62 bpm caused an increase of 205% in mean peak-to-peak amplitude but only an increase of 1.3% in mean ICP. The introduced soft robotic actuator system is capable of ICP waveform manipulation. Continuous amplification of the intracranial pulse pressure could enable in vivo modeling of normal pressure hydrocephalus and shunt system testing under pathophysiological conditions to improve therapy for hydrocephalus.

A Mixed‐Integer Linear Programming Framework for Optimization of Water Network Operations Problems

AbstractWater distribution systems (WDSs) are critical infrastructure used to convey water from sources to consumers. The mathematical framework governing the distribution of flows and heads in extended period simulations of WDSs lends itself to application in a wide range of optimization problems. Applying the classical mixed integer linear programming (MILP) approach to model WDSs hydraulics within an optimization framework can contribute to higher solution accuracy with lower computational effort. However, adapting WDSs models to conform to a MILP formulation has proven challenging because of the intrinsic non‐linearity of system hydraulics and the complexity associated with modeling hydraulic devices that influence the state of the WDS. This paper introduces MILPNet, an adjustable framework for WDSs that can be used to build and solve an extensive array of MILP optimization problems. MILPNet includes constraints that represent the mass balance and energy conservation equations, hydraulic devices, control rules, and status checks. To conform to MILP structure, MILPNet employs piece‐wise linear approximation and integer programming. MILPNet was implemented and tested using Gurobi Python API. Modeling accuracy was shown to be comparable to EPANET, a public domain software for hydraulic modeling, and sensitivity analyses were conducted to examine the impacts of the modeling assumptions on the performance of MILPNet. Additionally, application of the framework was demonstrated using pump scheduling optimization examples in single and rolling horizon scenarios. Our results show that MILPNet can facilitate the construction and solution of optimization problems for a range of applications in WDSs operations.

Design and analysis of plantar hydraulic control device for body weight support treadmill training

Design and analysis of plantar hydraulic control device for body weight support treadmill training

Research on Pump-Controlled AGC Micro-Displacement Position Control of Lithium Battery Pole Strip Mill Based on Friction Compensation Control Strategy of Imoroved LuGre Pattern

Accurate mathematical patterning of friction has always been a significant research project in the domains of machinery and control, and has played a crucial role in the analysis, control and compensation of mechanical systems containing friction. For high-property electrohydraulic servo control systems, friction compensation is an urgent problem to be solved. The LuGre friction pattern can represent most frictional behaviors, but the LuGre friction pattern is piecewise-continuous, making it non-differentiable. Therefore, the question of how to combine the LuGre friction pattern, enhancing its tracking capacity and robust performance problem, to friction perturbation in hydraulic backstep devices is an important focus for research. In this study, the conventional LuGre friction pattern was enhanced using the continuous differentiability of a friction of rest pattern that laid the foundation of a smooth tangent function. Laying the foundation of an electrohydraulic servo pump-controlled hydraulic roll-gap thickness automatic control system (pump-controlled AGC) pattern, a self-adapting friction compensation controller laid the foundation of the enhanced LuGre pattern. The gradual tracking capacity was determined academically using conditions of parameter, uncertainty and nonlinear friction, and the position control precision of the pump-controlled AGC system was enhanced. The steady-state error of the self-adapting friction compensation control system, which laid the foundation of the enhanced LuGre pattern, attained ±0.1 μm, and the tracking capacity was better than the LuGre pattern control and the conventional PID control strategy at low input speed.

The validity and reliability of a hydraulic resistance device for assessing resisted sprint time.

The aim of this study was to assess the validity and reliability of a hydraulic resistance device (HRD) for monitoring sprint split times under different loads within and between sessions. Three 20-m sprints with low (15 N), medium-low (40 N), medium-high (50 N), and high (130 N) HRD resistance levels (loads) were performed on two separate occasions 14 days apart. Twenty-four student athletes (24.8 ± 3.8 years) participated in the first session and 13 (24.1 ± 3.2 years) of them in the second session. Resisted sprints split times over a distance of 0-20 m (t0-5, t0-10, t0-20, t5-10, t10-15, t15-20) were measured simultaneously with magnetic incremental encoder embedded in the HRD and a system of single-beam timing gates. The results showed acceptable to high within session (ICC3,1 = 0.91-0.99; CV = 0.92%-3.38%) and between session (ICC3,1 = 0.82-0.99; CV = 1.62%-4.84%) reliability of HRD for measuring all split times at all loads. The minimal detectable change between sessions ranged from 3.3% at high load to 9.9% at low load. The HRD systematically underestimated timing gates times at all loads (bias = 2.01-11.08%), yet good to excellent consistency was observed between the HRD and timing gates, specifically for t0-10 and t0-20 (ICC3,k lower 95% CI = 0.84-0.99). Due to high reliability and good validity in monitoring resisted sprint times, the HRD holds potential for practical and research applications.

Analysis of Vibration Characteristics of Hydraulic Excavator Device Under Flat Ground Conditions

Hydraulic excavators, characterized by their high efficiency and versatility, are crucial equipment in engineering construction. During the automatic excavation process, the excavator may experience resonance phenomena, which can affect the stability of the entire system. In order to study the vibration harmonic response of the excavator arm in the process of reciprocating motion, firstly, the model of the excavator arm is designed in three‐dimensional software, and the finite element meshing software is used to perform hexahedral meshing of the excavator arm model and define the material properties. Secondly, the modal analysis of the excavator arm is carried out by finite element simulation software, and the displacement and acceleration harmonic response analysis is carried out using the modal superposition method. Finally, the vibration experiment of reciprocating motion with different frequencies is carried out on the experimental platform of the excavator arm. The simulation and experimental results show that the maximum value of the displacement and acceleration response of the excavator arm corresponds to the frequency near the second‐order intrinsic frequency, and the excavator arm is greatly affected by the second‐order intrinsic frequency; controlling the frequency of the reciprocating motion of the hydraulic cylinder within 13 Hz can effectively avoid the resonance phenomenon of the excavator arm device.

Analysis of Equipment Management Methods for Pumped Storage Power Stations Under the “Dual-Carbon” Goals

Pumped-storage, as the most mature technology, economically optimal, and most suitable for largescale development, plays a crucial role in promoting the consumption of clean energy and supporting the construction of new energy systems. Pumped-storage power stations involve various types of equipment such as hydraulic and electrical devices. The frequent start-stop operation in the context of new energy system construction will pose significant challenges to the equipment. This paper proposes a reliability-centered health management method for pumped-storage equipment. It implements differentiated and hierarchical management strategies for various types of equipment and establishes differentiated equipment maintenance strategies based on this.The project takes the manhole door of a power station governor pressure oil tank with nitrile rubber sealing ring as an example to calculate the service life in actual working conditions. Through calculation, it is considered that when reliability is 99%, the service life can be extended for more than 5 years, and if the reliability is 100%, the service life can be extended for more than 1 year.

PROCEDURE FOR DESIGN OF DOWNHOLE DAMPING DEVICES USING ELASTOMERS

The article is devoted to the problem of combating vibration and shock loads in the oil production industry. Described is a method of reducing loads due to the use of dampers in the design of devices. It is indicated that for damping vibration loads in mechanical engineering a wide range of design solutions is used using hydraulic, pneumatic and mechanical systems and devices. The article compares the use of springs and elastomers as a damping element in mechanical structures of downhole devices. It is also indicated that it is recommended to use experimentally obtained dependencies to select the damping material of the elastomer: with vibration of forced vibrations from 13.5 to 23.5 Hz, the density of the material should be increased, and with forced vibrations from 25 to 50 Hz, on the contrary, the density of the material should be reduced.As a vibration-isolated object, the article considers the installations of electrically driven centrifugal pumps (ESP), in which, due to unstable operating conditions, modules are often divided with a fall («flight») at the bottomhole due to fatigue destruction of the connecting elements. Two patented structural solutions to combat vibration and impact loads due to inclusion of a damping module with an elastomer substrate made in one case with an external conical surface and in the other in the form of a cylindrical bushing are presented.In recent years, there has been a trend towards a decrease in the diameter of wells and, accordingly, casing pipes. Therefore, an ESP arrangement with a damping module with a substrate made in the form of a cylindrical sleeve is most acceptable. Since in this design it is possible to increase the damping capacity of the module by increasing the thickness of its substrate.For this damper design, a method for calculating the relative longitudinal compression strain of its elastic substrate has been developed. It is shown that in order to ensure radial extension of levers by the required value, it is necessary and sufficient to determine the maximum diameter of the deformed (compressed) cylindrical rubber bushing, which at the same time acquires a barrel-like shape with a curvature of the generatrix depending on the rubber material: density and tightening factor.

Non-Linear Pushover Analysis Of RCC Framed Structure By Providing Fluid Viscous Dampers At Different Locations

The increasing need of shelter in urban cities due to overpopulated spaces and land inadequacy people are forced to keep space and their needs strictly limited. High-rise buildings are the best solution for providing people spaces for living and to work on. In this age of urban development and rapid modernization the need of high-rise structures is rapidly increasing. As structures have become higher, structural engineering has become more difficult to achieve appropriate stability criteria. In tall buildings, stiffness is the key to sustainability. Fluid Viscous Dampers (FVD) are one of the efficient solutions for tall structures. These are hydraulic devices that, when stroked, dissipate the energy placed on a structure by seismic events. The viscous dampers convert the kinetic energy of the structural movement into heat and then dissipate that energy into the air, thereby obeying the laws of physics through the conservation of energy. To determine effectiveness of FVDs as well as determine best location for FVDs in high-rise buildings subjected to seismic loads, the current research is being carried out.In this study twelve (12) RCC framed structures of 15 storeys of which four (4) are square shaped in plan, four (4) are rectangle shaped in plan with sides of ratio 1.5:1 and the other four (4) are rectangle shaped in plan with sides of ratio 2:1. These three (3) different shaped buildings considered are having approximately same plan area and damper positions. A floor-to-floor height 3m is taken. The buildings are located in Zone III. By using ETABS 2017 software, which helps to analyse and design the models, the analysis method used for this study is the Push Over analysis. This research work presents the results of an investigation on different parameters like Base shear, Modal mass participation, Time period, Storey Drift, Storey Shear and Storey Stiffness.

ИСТОРИКО-ПРИРОДНЫЙ АРХИТЕКТУРНЫЙ КОМПЛЕКС «ПАРАМОНОВСКИХ» СКЛАДОВ В РОСТОВЕ-НА-ДОНУ

This paper examines the history and architecture of a unique historical and natural architectural complex of export grain warehouses of the second half of the XIX century in Rostov-on-Don. The objects under study are inextricably linked with the historical landscape, the Bogatyanovsky tract, and the urban environment. The buildings of grain warehouses stand on an ancient aquifer slope with springs and hydraulic devices for organizing their flows. The purpose of the study is a detailed examination of the object of cultural heritage of federal significance "Complex of export grain warehouses, XIX century.". In the course of the study, the architectural, artistic and design features of each of the buildings included in the complex of grain warehouses belonging to Paramonov and Maximov were formulated. The studied objects of export grain warehouses are decorated in a "brick" style. At that time, the "brick" style represented a fundamentally new compositional solution of volumes and a variety of plastic forms of brick decor, which conditioned the aesthetic perception of industrial architecture structures. The characteristic features corresponding to the "brick" style are revealed. The initial design solutions based on the preserved archival data on the object of cultural heritage were studied and project proposals for the reconstruction of warehouses with possible operation and adaptation to new functions in modern urban conditions were considered, new factual data were obtained.

Bed configurations downstream combined V-Notch-sharped edged Weir with inverted V-Shaped gate

ABSTRACT Weirs and gates are hydraulic structures installed in canals, mainly for controlling the discharge. Because of their existence, unfavorable influences regarding the downstream bed configurations were recorded. This study experimentally explores the combined effect of simultaneous flow through a hydraulic device consisting of a V-notch sharped weir with an inverted V-shaped gate, aiming to minimize the downstream bed scour. Eighty-one runs were carried out using nine weir-gate models with three different vertex angles. The tests were executed considering three upstream and three downstream water depths. A V-notch weir with an angle of 120º was tested under similar hydraulic conditions and was used for comparison. The results revealed that the length of backflow was increased by the decrease in weir angle under a fixed 120° gate angle. The bed configurations were sensitive to gate angle. The combined device showed a significant decrease in bed disturbances regardless of the angles used compared to the traditional V-notch weir. Simple formulas were developed to predict the scour parameters.

Investigation on the Design and Application of Hydraulic Loading Fatigue Test Device for Non-Vascular Stent

Investigation on the Design and Application of Hydraulic Loading Fatigue Test Device for Non-Vascular Stent

Testing of Regulating and Non-Regulating Hydraulic Pumps

Abstract This article deals with the testing of regulating and non-regulating hydraulic pumps in laboratory conditions. The laboratory test was carried out on the hydraulic device consisting of two separate hydraulic circuits (for testing the non-regulating hydraulic pump and regulating hydraulic pump). A throttle valve or proportional throttle valve is used for loading. During the laboratory tests, the flow efficiency of the non-regulating hydraulic pump at rotation speed n = 1,500 rpm (nominal speed) was η pp = 98.91% (0 MPa) and η pp = 94.97% (20 MPa), and for the regulating hydraulic pump, the values were η pp = 97.57% (0 MPa) and η pp = 94.54% (20 MPa). The determined values of flow efficiency of hydraulic pumps determine the correct operation of the experimental hydraulic laboratory equipment.

Experimental Studies on the Crack Initiation and Propagation of Hydraulic Fracturing with Different Coal Structure Combinations.

Coal structure is one of the key geological factors that affects the effect of coal reservoir stimulation. Based on the geological spatial combination characteristics, thickness, and proportion of different coal structures, the coal reservoir is divided into different coal structure combination types. The hydraulic fracturing device is used to carry out indoor fracturing experiments and dissect the crack initiation and expansion characteristics with different coal structure combinations. The results show that the coal structure combination is of the binary type (undeformed coal + granulated coal or cataclastic coal + granulated coal), and the undeformed coal (cataclastic coal) can overcome the tensile strength and minimum principal stress when it is driven by the high-pressure fluid. The undeformed coal (cataclastic coal) ruptures and forms longitudinal cracks. The increasing proportion of granulated coal inhibits crack expansion and promotes the transverse deformation of coal. The interface contact point between the undeformed coal (cataclastic coal) and granulated coal easily fractures along the cross section of the specimen. When the coal structure combination is the triplex type (undeformed coal + granulated coal + cataclastic coal or cataclastic coal + granulated coal + cataclastic coal), the undeformed coal or cataclastic coal is transformed. The forming fractures in the undeformed coal (cataclastic coal) can cut through the soft coal when the thickness of the undeformed coal (cataclastic coal) is large and the thickness of granulated coal is thin. On the contrary, it is not easy to cut through. When the coal structure combination is granulated coal + cataclastic coal + granulated coal, the cataclastic coal fails under shear stress and forms the crack along the cross section of the coal sample. The granulated coal inhibits the crack expansion at both ends. The research results have an important indicative significance for further understanding the fracture initiation and propagation mechanism of hydraulic fracturing with complex coal structures in coal reservoirs.

Analysis of the technical level of hydraulic fluid power with motor-wheels

The analysis of the use of hydraulic fluid power of rotation of hydraulic motor-wheels for tracked and wheeled machines was carried out. The hydraulic principle schemes for the use of high-speed axial-piston hydraulic motors with planetary gearboxes and high-torque low-speed radial-piston hydraulic motors are considered, in particular, hydraulic devices for ensuring reliable movement in the event of obstacles from the road surface. The features of static and dynamic calculation methods using a mathematical model for the numerical solution of differential equations when calculating pressure fluctuations and the frequency of rotation of hydraulic motors depending on the tasks of changing the intensity of the pump supply and the working volume of the hydraulic motor, taking into account its efficiency, are shown. A comparative analysis of the technical level of hydraulic motor-wheels was carried out and a significant increase in the output parameters of high-torque radial piston hydraulic motors with respect to pressure, rotation frequency and mass-to-torque ratio was revealed. The article may be useful for engineers, scientists and master's students.

Increasing the Resistance to Cavitation Erosion of 6082 Aluminum Alloys through Thermal Aging Treatments at 140°C and Holding Time of 12 Hours

The use of aluminum alloys in the manufacture of hydropneumatic systems components is very known. However, the knowledge of their behavior under cavitational demands, determinated of flow of the working liquid, is limited. For this reason, in recent years, the older research, carried out on this type of material and on some of its alloys, regarding the resistance to cavity erosion, has been resumed, especially since the mechanical properties and reduced mass are an advantage for the parts that work in this conditions (ship propellers, pumps and bodies of hydraulic devices, etc.). Therefore, the results of this paper are in step with the new researches, highlighting the behavior and resistance to the erosion produced by vibrating cavitation on the aluminum alloy 6082 subjected to the thermal aging treatment at 140 °C, with a holding time of 12 hours. The performance evaluation is based on the characteristic curves of the cavity, the specific parameters and the macro and microstructural investigations. The comparison with the delivered state shows a double increase in resistance from the cavitational erosion created by the shock waves and microjets.

Temporal bone phantom for decoupled cochlear implant electrode insertion force measurement

Abstract In research on cochlear implants, preclinical testing of newly developed electrode arrays and surgical tools is an essential procedure, which requires the availability of a suitable testing environment. For this purpose, human temporal bone specimens are most realistic, but their availability is limited and additional parameters such as insertion forces are hardly measurable. Therefore, the aim of this study was to develop a temporal bone phantom with realistic anatomical structures for intracochlear force measurement. The temporal bone was segmented from CBCT data of a human cadaver head. The segmented model was 3D printed with an additional artificial skin layer to enable the simulated use of surgical instruments such as a self-retaining retractor. A mechanically decoupled artificial cochlear model was realistically positioned within the temporal bone and was furthermore attached to a force sensor. The usability of the phantom was evaluated by performing automated EA insertions using an automated hydraulic insertion device. The experiments showed that the insertion forces within the cochlea could be measured without interferences from surrounding structures. Moreover, the artificial skin provided a rigid interface for the insertion tool. The new phantom is a realistic testing and training platform for cochlear implant electrode insertions with the advantage of measureable insertion forces.

Safety Evaluation of Hinged Pump-Type Water Gate Fixing Device

In several mountainous areas in Korea, the number of small-scale storage facilities are on the rise. The safety of the opening and closing devices of sluice gates used in storage facilities is important. Recently, during the opening and closing of a water gate that used hydraulic pressure, sagging had occurred owing to the loss of hydraulic pressure over time. To solve the sagging problem of the water gate, a hydraulic loss prevention fixing device is used. The purpose of this study is to induce the safety design of a water gate through a theoretical and numerical review of the safety of a fixing device of the water gate. First, to theoretically secure the stability of the water gate fixing device, the fixing device was simplified and analyzed using the transformed-section method considering its cross-sectional height. In addition, the simplified fixing device assumed the point conditions according to the connection type, and the maximum deflection occurring in the fixing device was calculated considering the cross section conversion under the condition of the load acting on it. Through this structural analysis, the maximum deflection problem and stress generated in the fixing device were confirmed, and the safety of the fixing device was assessed to present its safety standard. The FE numerical analysis performed for comparative verification was interpreted as a condition of linear elasticity of isotropy in the fixing device. Consequently, a safety design method for the pump-type water gate fixing device was presented through the theoretical and numerical verification for securing its safety.