Analysis Of Hydraulic System Research Articles

The Evaluation of Water Loss in The Western North Tarum Irrigation Channel

The Western North Tarum Irrigation channel plays a crucial role in supplying water to irrigated agricultural areas. However, it encounters challenges in ensuring adequate water delivery to all channel segments. This research assesses water loss during the distribution process in the Western North Tarum Irrigation channel, focusing on the evaluation of channel capacity and the impact of suboptimal water management on water loss. The study employs the HEC-RAS model, a hydraulic system analysis tool, to evaluate the channel’s capacity and simulates its behavior under various discharge conditions. The evaluation reveals that two channel segments, B.TUB 13 and B.TUB 25, have exceeded their capacity limits, resulting in overflow. Sedimentation downstream, particularly in these segments, exacerbates the issue by altering the channel slope and impeding water flow. This research identifies poor water distribution management as a significant factor contributing to water loss in the irrigation channel. Inadequate scheduling and the absence of proper water measurement tools result in instances of overwatering or underwatering in some areas. The lack of monitoring and control in the irrigation system hampers the detection of uncontrolled flow in the channels, leading to substantial water loss and inefficient water use. This research underscores the importance of evaluating and maintaining irrigation channel capacity to prevent overflow and water loss. Furthermore, it emphasizes the significance of effective water management to achieve more efficient water distribution and irrigation. Addressing these challenges is crucial for ensuring the long-term sustainability of irrigated agriculture in the Western North Tarum Irrigation area.Keywords: HEC-RAS, Irrigation Channel, Water Distribution, Water Loss, Western North Tarum

Safe Energy using Hydraulic System Analysis at a Hydropower Plant

The Hydro-PowerStation is one of the keys (important) sources of electricity, and it has a digital governor, which improves production efficiency over mechanical governors. This research looked at the hydraulic turbine, found flaws such as oil leakage from the pumps utilized, calculated the amount of energy consumed, and worked to reduce it by measuring the losses and monitoring the poor process during periods of high water load of up to 83%. As a consequence of the research, it was discovered that the amount of energy consumed had decreased by 20%, by employing well-made, effective pumps for each unit according to its use, oil leakage in all units is reduced.

Characteristics analysis and nonlinear control of a digital hydraulic pressure tracking system for high-speed helicopter wet friction clutch

The reliability and control precision of the engagement and disengagement of wet friction clutch are crucial to the transmission of high-speed helicopters. In contrast to the traditional proportional hydraulic system, the digital hydraulic system provides a viable solution due to the use of several fast switching valves (FSVs). In this research, a digital hydraulic pressure tracking system using two fast switching valve arrays (DHPTS-FSVA) is proposed and its nonlinear model is established. First, the static and dynamic characteristics of the DHPTS-FSVA are deeply analyzed by virtue of the half-bridge resistance theory. Moreover, a novel pressure control strategy is proposed, which consists of nonlinear adaptive control method, differential pulse width modulation (PWM) with pressure compensation, and logic allocation strategy of PWM duty ratio. Finally, comparative simulation and experimental results indicate that the maximum, average, and standard deviation of the errors are reduced by at least 16.1%, 45.1%, and 39.5%, respectively, at the tracking frequencies of 1 and 2 Hz, which proves that the proposed controller exhibits better tracking performance at low frequencies.

CFD Applications to Pressurized Thermal Shock-Related Phenomena

In pressurized water reactor accident scenarios, the injection of water from the emergency core cooling system (ECCS) (ECC injection) might induce a pressurized thermal shock (PTS), affecting the reactor pressure vessel (RPV) integrity. Therefore, PTS is a vital research issue in reactor safety, and its analysis is essential for evaluating the integrity of RPVs, which determines the reactor life. The PTS analysis comprises a coupled analysis between thermal–hydraulic and structural analyses. The thermal–hydraulic approach is particularly crucial, and reliable computational fluid dynamic (CFD) simulations should play a vital role in the future because predicting the temperature gradient of the RPV wall requires data on the transient temperature distribution of the downcomer (DC). Since one-dimensional codes cannot predict the complex three-dimensional flow features during ECC injection, PTS is one reactor safety issue where CFD simulation can benefit from complement evaluations with thermal–hydraulic system analysis codes. This study reviewed from the viewpoint of the turbulence models most affecting PTS analysis based on papers published since 2010 on single- and two-phase flow CFD simulation for the experiment on PTS performed in the Rossendorf coolant mixing model (ROCOM), transient two-phase flow (TOPFLOW), upper plenum test facility (UPTF), and large-scale test facility (LSTF). The results revealed that in single-phase flow CFD simulation, where knowledge and experience are sufficient, various turbulence models have been considered, and many analyses using large eddy simulation (LES) have been reported. For two-phase flow analysis of air–water conditions, interface capturing/tracking methods were used in addition to two-fluid models. The standard k–ε and shear stress transport (SST) k–ω models were still in the validated phase, and various turbulence models have yet to be fully validated. In the two-phase flow analysis of steam–water conditions, many studies have used two-fluid models and Reynolds-averaged Navier-Stoke (RANS), and NEPTUNE_CFD, in particular, has been reported to show excellent prediction performance based on years of accumulated validation.

PERANCANGAN SISTEM HIDROLIK PADA MESIN PRESS BAMBU LAMINASI

The hydraulic system is a power transmission system by using the compressive energy of the fluid into mechanical energy to obtain a power greater than the initial power released. The press machine is one of the pieces of equipment that apply the hydraulic system. In the process of making laminated bamboo, the bamboo gluing technique is assisted using a press machine. Based on observations, the press machine used is a manual press machine, so the pressing process is not efficient. This study aims to increase the effectiveness of pressing laminated bamboo. The results of the study found that the press machine has 4 hydraulic cylinders so the pressing process can be carried out at several points simultaneously. The results of the hydraulic system analysis diagram show hydraulic cylinder moves in 16,9 seconds with a pressure of 100 bar, so the pressing process is fast. Mathematical calculations produce data, a hydraulic gear pump with a displacement of 13 cc/rev, electric motor power of 3,7 kW, hydraulic cylinder diameter of 63 mm, cylinder rod of 35 mm, rod of 400 mm, and a hydraulic tank capacity of 12 liters.

Quantitative stability analysis of complex nonlinear hydraulic turbine regulation system based on accurate calculation

The current stability studies of the hydraulic turbine regulation system (HTRS) mostly adopt the linear hydro-turbine model ignoring its strong nonlinearity, leading to insufficient disclosure of the true characteristics of the HTRS and also causing great inconvenience to the controller parameter tuning. To address this issue, based on the Hopf bifurcation theory, bisection method, and stability criterion, this paper proposes an algorithm (HBBSC) for determining the controller parameter constraint considering the nonlinearity of the hydro-turbine. Firstly, the nonlinear model of the hydro-turbine is constructed based on the model reconstruction strategy (NNGW) combining the backpropagation neural network (BPNN) with the improved grey wolf optimization algorithm (IGWO) to obtain an accurate nonlinear HTRS numerical simulation platform under the power control mode (PCM) and frequency control mode (FCM). Then, the HBBSC-based quantitative calculation procedure of stability region constraint is introduced in detail. Further, in a case study of stability region calculation of HTRS, the HBBSC is applied to calculate the stability region constraint, and the HBBSC-based stability region is verified through a simulation platform. Finally, the stability region of complex HTRS under all operating conditions is calculated based on HBBSC. The results indicate that the HBBSC can replace the traditional methods for stability region calculation during stability analysis of HTRS, outperforming the latter in accuracy and reliability.

Fault Analysis and Diagnosis of Downhole Traction Robot Hydraulic System

Fault diagnosis of downhole traction robot has characteristics of special mechanical structure, complicated working condition and lack of research data. In this paper, a method of fault analysis and diagnosis of tractor hydraulic system based on model is presented. The failure mode and mechanism of key components in telescopic hydraulic system are analyzed. The fault diagnosis of hydraulic system is proposed based on the mathematical model of hydraulic component. Based on AMESim, the fault model of hydraulic system is established, and the diagnosis of single fault and multi-fault are simulated, which can collect the fault data and the specific diagnosis process. To carry forward the engineering application, the simulated internal leakage system in cylinder is set up and schemes of fault diagnosis are carried out, which prove that the diagnosis is consistent with theoretical analysis and simulation. The research on fault analysis and diagnosis of the downhole traction robot hydraulic system not only lays theoretical basis for the tractor fault detection, but also provides guidance for the construction and implementation of the diagnostic system.

Nonlinear dynamic analysis of power reflux hydraulic transmission system

Power reflux hydraulic transmission system (PRHTS), which is a recently introduced continuously variable transmission system, enables the improvement of fuel economy of construction vehicles. For investigating the nonlinear dynamic characteristics of PRHTS, its nonlinear dynamic model is established by merging the dynamic models of a planetary gear train and torque converter. A dynamical model of the planetary gear train reveals the parameters of mesh damping, time-varying mesh stiffness, and transmission error. The nonlinear dynamic equations of the PRHTS are solved using the fourth-order Runge-Kutta method. The dynamic orbits of the system are observed through bifurcation diagrams, which use the internal excitation frequency and meshing damping ratios, both of which are dimensionless, as control parameters. Numerical examples show the dynamic evolution mechanism involving one-period motion, multi-periodic motion, quasi-periodic motion, and chaotic motion. The onset of chaotic motion is identified from bifurcation diagrams, dynamic trajectories, phase plane diagram, and Poincaré maps of the PRHTS. The simulation results provide an understanding of the operating conditions under which undesirable dynamic motion occurs in PRHTS and serve as invaluable information for effective dynamic design of PRHTS.

Discrete impedance method for the oscillation analysis of pumped-storage power plants

As the proportion of new energy increases in modern power systems, pumped-storage power plant attaches significance to balancing power supply and demand. Its operational stability has attracted extensive attention. Since the hydraulic characteristics of the pumped-storage power plant with a complicated conduit system are rather complex, it is difficult for the traditional continuous impedance method to obtain analytical solutions to the frequency responses directly. Therefore, an equivalent circuit modeling-based discrete impedance method is proposed to address this problem. The discrete impedance method possesses accurate modeling precision and is applied to the oscillation analysis of a pumped-storage power plant with a complex hydraulic network. Furthermore, the influences of the pump-turbine impedance and the pipe friction loss on the oscillation characteristics have been discussed. Numerical results indicate that the variations of the pump-turbine impedance and pipe friction loss impact the decay coefficients of different oscillation orders, thus influencing the system’s stability. However, they can hardly affect the eigen frequencies of the system. The proposed discrete impedance provides an alternative to the complex frequency analysis of complicated hydraulic systems.

Analysis of CNC machine tool self-circulating hydraulic balance system

Analysis of CNC machine tool self-circulating hydraulic balance system

Simulation Analysis of Hydraulic Control System of Engineering Robot Arm Based on ADAMS

Simulation Analysis of Hydraulic Control System of Engineering Robot Arm Based on ADAMS

Vibration Analysis of Multi-Branch Hydraulic Pipeline System Considering Fluid—Structure Interaction

A multi-branch pipeline is a typical structure, which is widely used in aerospace, marine and other hydraulic systems. The multi-branch pipeline suffers serious vibration from fluid–structure interaction, which can cause vibration failures in the pipeline system through overload in engineering fields. Vibrational analysis of the multi-branch pipeline system is increasing as part of the design of hydraulic system. In this paper, the finite element model of a multi-branch pipeline considering fluid—structure interaction is established, and the effectiveness of the modeling is validated through a comparison of the modal test for a typical four-way pipeline. The effects of the flow rate, pressure, fluid medium, pipe diameter, elastic constraint stiffness, and pipeline length and wall thickness on the dynamic characteristics of pipeline system are all considered. The obtained results indicate that the multi-branch junction suffering from significant vortex fluid is the main cause of fluid-induced vibration of the pipeline system. The fluid and structural parameters have great influence on the vibration characteristics of the pipeline, which can serve as an efficient tool in the design and maintenance of multi-branch hydraulic pipeline systems.

TURBINE SPEED CONTROL

Provides analysis of hydraulic turbine control systems existing in the world and domestic practice. The design features of constructing circuits with discrete and discrete-analog control methods are considered. The schemes for controlling the speed of the turbine of the leading manufacturers of hydraulic turbine equipment are given: PO "LMZ" and ALSTOM POWER HYDRO (France, Grenoble). The given computer system of hydraulic turbine speed control guarantees trouble-free operation in case of load deviation and power failures. A fully automatic method of controlling the hydraulic unit is possible, in which the computer system controls the turbine independently, based on the parameters of the hydraulic unit operation taken into account by the sensors, in accordance with the program of the control computer. The control system constantly monitors the operation of the hydraulic turbine, adjusts its speed according to the load, performs adequate control operations. The analysis of the operation of the circuits is carried out, taking into account the specifics of the functioning of the regulation system. A mathematical model of the hydromechanical part of the regulator is considered for assessing the quality indicators of transient processes occurring in the process of starting, stopping and reversing a hydraulic turbine. It is shown that the development of theory and design methods using both approaches, mathematical models and control algorithms aimed at increasing the positioning accuracy and reliability of hydropneumatic systems with a possible simplification of circuit solutions is an important task aimed at obtaining a significant economic effect when solving this most important problem. The results obtained prove that the use of a positional hydraulicpneumatic drive for building a hydraulic turbine speed control system with discrete and discrete-analogue control makes it possible to synthesize a hydraulic pneumatic drive with high positioning accuracy, without the use of expensive hydraulic valves with proportional control.

Random response analysis of hydraulic pipeline systems under fluid fluctuation and base motion

Aero hydraulic pipeline systems are subjected to internal fluid fluctuations and random base motions during operation, resulting in time-varying system parameters and nonstationary random responses. To analyse this situation, a nonstationary random response analysis method and a fatigue damage assessment formula for periodic time-varying systems under stationary random excitations are proposed. The nonstationary random response is described by a time-varying power spectral density function, which is strictly characterised by a set of pseudo responses of a periodic time-varying system under a series of harmonic excitations. A frequency-domain iterative solution format for the pseudo responses is constructed and combined with the fast Fourier transform to obtain the time-varying power spectral density function. A fatigue damage assessment formula is derived by discretising the time-varying power spectral density function of the pipeline stress in both the time and frequency domains. The proposed method only requires a few iterations at specific frequency points to calculate each pseudo response in a wide-band random airframe motion environment, showing high computational efficiency. A practical application concerning a section of the wingtip hydraulic pipeline is presented to demonstrate the correctness and efficiency of this method. The variations of pipeline responses and fatigue damage rates under fluid fluctuations and random base motions are also discussed.

Analysis of hydraulic system’s weak fault based on variable parameter multi-scale permutation entropy and deep belief network

Aiming at automatic recognition of hydraulic system’s weak fault, an analysis method based on variable parameter multi-scale permutation entropy (VPMPE) and deep belief network (DBN) is proposed in this paper. The external vibration signals of experimental hydraulic equipment in normal state and three different leakage state (slight, moderate and severe) are taken as research object. By the proposed method, experiment signals are first processed to obtain their multi-scale permutation entropy in different conditions by changing the embedding dimension m and the scale factor s, then the multi-scale permutation entropy under different m and s are combined to form feature vectors, and lastly the DBN classifier is used to identify and analyze the testing samples. Verification test shows that the proposed method has good effects on hydraulic system’s weak fault, which can accurately judge whether there is leakage fault and measure the fault severity.

ГИДРОДИНАМИЧЕСКИЙ АНАЛИЗ ПРОЦЕССОВ ТОПЛИВНЫХ СИСТЕМ ТИПА «COMMON RAIL» В СРЕДЕ ИМИТАЦИОННОГО МОДЕЛИРОВАНИЯ AVL BOOST HYDSIM

The study objective is modeling hydro-dynamic processes occurring in an electro-magnetic diesel fuel injector using AVL Boost Hydsim software package (SP).
 The task to which the paper is devoted is the design of equipment for Common Rail battery injection and fuel atomization systems; description of methods for developing battery fuel systems using Hydsim SP.
 Research methods: numerical simulation of fuel supply based on hydrodynamic dependencies describing the compressible viscous fluid motion in Hydsim software environment.
 Novelty of the work: due to constant tightening of environmental, technical and economic requirements for diesel internal combustion engines (ICE), which directly depend on the perfection of the fuel supply system, there is a need for software that allows engineers to design the appropriate fuel equipment. It is also important to have an effective and comprehensive methodology for working with such software solutions.
 Research results: a model of an electromagnetic fuel injector of a diesel engine is developed, a brief description is given of the methodology for constructing a hydraulic model of the nozzle (in a two-dimensional problem statement) and an analysis of the simulation results obtained.
 Conclusions: AVL Boost Hydsim SP has a number of advantages over its competitors, which can significantly reduce the time spent on the design and implementation of modern fuel equipment, opportunities for dynamic analysis of hydraulic and hydromechanical engine systems appear.

A dynamic modeling approach for vibration analysis of hydraulic pipeline system with pipe fitting

The hydraulic pipeline system with pipe fitting in the aircraft is subjected to both hydraulic pump fluid and engine-induced excitation. It is essential to investigate the vibration characteristics of pipeline systems with fittings. This paper proposed a dynamic modeling approach for vibration analysis of hydraulic pipeline system with fitting. Firstly, the relationship between the tightening torque and the pipe fitting stiffness is obtained. Then, the dynamic modeling of the hydraulic pipeline system with fitting is established via the finite element method. A pipeline with fitting is investigated as a numerical example to validate the present approach. The effects of the fitting friction coefficient, pipeline diameter and length on the modal frequencies of pipeline system are further analyzed. The results show that the natural frequencies of the pipeline increase non-linearly with the increasing of tightening torque and friction coefficient. When the tightening torque is greater than 8 N·m, the natural frequencies of the pipeline system tend to be stable. Moreover, the natural frequencies of the pipeline system increase significantly with the increasing of pipe fitting diameter. However, the increasing of pipeline length decreases the natural frequencies of the pipeline system. The results indicate that the current modeling approach can serve as an efficient guidance for the design of hydraulic pipeline systems.

Fault Analysis and Elimination of Hydraulic Driving System for Rubber Rig in Coal Mine

Aiming at the failure of the rubber wheel drilling rig with unstable walking speed during use, the principle of the walking hydraulic system is introduced, the cause of the failure is analyzed, and the principle of first easy and then difficult, first observation and then dismantling and inspection is followed. According to the output pressure of the differential valve block and the output characteristics of the hydraulic pump, combined with the principle of the hydraulic travel system, it is finally determined that the internal leakage of the differential valve block is the main cause of the failure. After replacing the differential valve block, the fault was eliminated, and the traveling system of the whole machine returned to normal.

Time‐ and frequency‐domain analyses of the hydraulic system using a discrete numerical scheme based on equivalent circuit modelling

Mathematical modeling is widely used for the time-and frequency-domain analysis of hydraulic systems. To explore the complicated hydraulic transients of the piping system under various operating conditions, different formulations of the equivalent circuit model (ECM) are systematically discussed in this study. In particular, comparative studies are performed regarding the restrictions on the tempo-spatial discretization of the time-domain ECM and the state-of-the-art numerical schemes. In addition, the eigenanalysis of the free oscillation response and frequency features of the forced oscillation response were discussed in detail, respectively. Furthermore, the influence of spatial discretization on the frequency response precision for ECM is also quantified. Analytical results indicate that the ECM can achieve satisfactory performances in both numerical simulation and frequency analysis with affordable computational effort and relatively loose tempo-spatial discretization restriction.

Vibration Reduction Characteristics and Vibration Control of Aviation Hydraulic Pipeline by Hard Coating

Aviation hydraulic pipelines are an important channel for power transmission in aviation hydraulic systems. Due to long-term exposure to complex vibration environments, hydraulic pipeline systems are susceptible to accumulated fatigue damage failure, which poses a great threat to aircraft safety and reliability. At present, there are only passive ways to reduce hydraulic pipeline vibration, such as adding vibration isolators and damping bearings. These methods have a poor vibration damping effect and are not safe. In this study, a hard coating was used as a new vibration reduction method for aviation hydraulic pipelines to reduce the damage caused by vibrations. For this purpose, three different hard-coating materials were optimally selected, and model creation, finite element analysis, and experimental research were carried out to study the vibration responses of hard-coated aviation hydraulic pipelines under the actual working conditions of an aircraft. The optimal solution was obtained through orthogonal experiments. The vibration reduction rate of the aviation hydraulic pipelines could reach 20.33% under the constant-frequency excitation of the low-pressure rotor of the engine, and the vibration reduction rate under the constant-frequency excitation of the high-pressure rotor could reach 26.60%. The rationality of the model was verified, and it was proven that the hard coating could meet the demands of vibration control in practical engineering and provide a reference for the vibration analysis and vibration control design of aviation hydraulic piping systems.