scholarly journals Reducing the hydrodynamic force in the hydraulic distributor by modernizing the spool coupe parts

2021 ◽  
Vol 7 (4) ◽  
pp. 356-368
Author(s):  
A.O. Svoykin ◽  
Keyword(s):  
Analytical Solution ◽  
Numerical Experiment ◽  
Hydrodynamic Force ◽  
Flow Simulation ◽  
Economic Benefits ◽  
Hydrodynamic Forces ◽  
Sharp Change ◽  
Original Design ◽  
Control Power ◽  
Comparison Of The Results

Due to a sharp change in the direction and velocity of the fluid flow in the hydraulic distributor, hydrodynamic forces arise. When positioning and holding the spool, the magnitude of the above forces determines the required control power. The aim of the article was to find an optimal constructive solution that would reduce the influence of hydrodynamic forces. In the article we have considered the theoretical foundations laid in the analytical solution of the problem of calculating the magnitude of the hydrodynamic force acting on the plunger of the spool. In addition, a numerical experiment was carried out using CAD Solidworks and the Flow Simulation application package and a comparison of the results obtained with the analytical solution of the problem. During the numerical experiment, it was found that by upgrading the spool sleeve, it is possible to reduce the value of the hydrodynamic force by 4.5 times, compared with the original design. At the same time, it was found that the modernization of the plunger does not further reduce the maximum hydrodynamic forces. The article highlights the economic benefits of reducing the required power to control the hydraulic distributor. The article may be of interest to both researchers whose research interests lie in the field of hydrodynamics, and manufacturers of hydraulics.

scholarly journals Research on Gas-liquid Mixed Transportation Technological Adaptability: A Case Study of the Western Sichuan Gas Field

2017 ◽  
Vol 10 (1) ◽  
pp. 37-47
Author(s):  
Qingsha Zhou ◽  
Kun Huang ◽  
Yongchun Zhou
Keyword(s):  
Flow Simulation ◽  
Field Tests ◽  
Economic Benefits ◽  
Gas Production ◽  
Simulation Software ◽  
Rapid Decline ◽  
Gas Field ◽  
Western Sichuan ◽  
Field Development ◽  
Well Production

Background: The western Sichuan gas field belongs to the low-permeability, tight gas reservoirs, which are characterized by rapid decline in initial production of single-well production, short periods of stable production, and long periods of late-stage, low-pressure, low-yield production. Objective: It is necessary to continue pursuing the optimization of transportation processes. Method: This paper describes research on mixed transportation based on simplified measurements with liquid-based technology and the simulation of multiphase processes using the PIPEPHASE multiphase flow simulation software to determine boundary values for the liquid carrying process. Conclusion: The simulation produced several different recommendations for the production and maximum multiphase distance along with difference in elevation. Field tests were then conducted to determine the suitability of mixed transportation in western Sichuan, so as to ensure smooth progress with fluid metering, optimize the gathering process in order to achieve stable and efficient gas production, and improve the economic benefits of gas field development.

scholarly journals Learning the basics of a battery pack control system

2020 ◽  
Vol 164 ◽  
pp. 13006 ◽  
Author(s):  
Kirill Kobzev ◽  
Sergey Vyalov ◽  
Alexander Rybak
Keyword(s):  
Mathematical Model ◽  
Control System ◽  
Numerical Experiment ◽  
Structural Parameters ◽  
Operation Mode ◽  
Power Source ◽  
Design Parameters ◽  
Hydraulic Systems ◽  
Original Design ◽  
Functional Features

The article discusses the control system of a hydraulic power source of constant pressure, which is a pump-storage power source, equipped with the original design of the automatic unloading of the hydraulic pump, which provides relay switching of its operation mode. A mathematical model is proposed, obtained using a modeling technique based on the application of the theory of volumetric rigidity of hydraulic systems and their elements. The results of a numerical experiment carried out by numerically solving the equations that make up the mathematical model of a power source are also presented. As a result of a numerical experiment, the main technical capabilities of the considered power source and the influence of its main structural parameters and functional features of the system on operational properties are revealed. The results showed that due to changes in various design parameters of the unloading machine, you can not only change the upper (maximum) and lower (minimum) values of the battery charging pressure, but also adjust their difference depending on the requirements for the power source. The main property of a power source with an automatic unloading device of the proposed design, confirmed as a result of a numerical experiment, is that the automatic unloading device provides a clear relay switching of the pump operation mode from unloading to operating mode and vice versa. The revealed properties make it very promising to use a pump-accumulator power source in the hydraulic systems of mobile machines and technological equipment.

scholarly journals Economic and theoretical study of the power supply from a pump-battery based on a discharge machine

2020 ◽  
Vol 175 ◽  
pp. 05042
Author(s):  
Kirill Kobzev ◽  
Sergey Vyalov ◽  
Alexander Rybak
Keyword(s):  
Mathematical Model ◽  
Numerical Experiment ◽  
Structural Parameters ◽  
Operation Mode ◽  
Power Source ◽  
Design Parameters ◽  
Hydraulic Systems ◽  
Original Design ◽  
Functional Features ◽  
Pump Storage Power

The article discusses the control system of a hydraulic power source of constant pressure, which is a pump-storage power source, equipped with the original design of the automatic unloading of the hydraulic pump, which provides relay switching of its operation mode. A mathematical model is proposed, obtained using a modeling technique based on the application of the theory of volumetric rigidity of hydraulic systems and their elements. The results of a numerical experiment carried out by numerically solving the equations that make up the mathematical model of a power source are also presented. As a result of a numerical experiment, the main technical capabilities of the considered power source and the influence of its main structural parameters and functional features of the system on operational properties are revealed. The results showed that due to changes in various design parameters of the unloading machine, you can not only change the upper (maximum) and lower (minimum) values of the battery charging pressure, but also adjust their difference depending on the requirements for the power source.

Hydrodynamic Forces on Subsea Pipelines due to Orbital Wave Effects

2013 ◽  
Author(s):  
Annelise Karreman ◽  
Jeremy Leggoe ◽  
Terry Griffiths ◽  
Lisa King ◽  
Nino Fogliani
Keyword(s):  
Vertical Velocity ◽  
Large Diameter ◽  
Significant Proportion ◽  
Economic Benefits ◽  
Hydrodynamic Forces ◽  
Design Methods ◽  
Fundamental Aspect ◽  
Experimental Investigations ◽  
Rectilinear Motion ◽  
Particle Paths

Ensuring pipeline stability is a fundamental aspect of subsea pipeline design and can contribute a significant proportion of project costs in regions with large diameter trunklines, shallow water and severe geotechnical and metocean conditions [1]. Reducing the conservatism and simplifications of existing pipeline stabilisation design methods therefore offers economic benefits to hydrocarbon producers necessary to ensure the ongoing viability of projects in these regions. To realise this potential and reduce the conservatism of the existing design methods, a more accurate understanding of the hydrodynamic loads exerted by waves and currents is required. This paper investigates one of the inherent assumptions incorporated into the existing design methods through the arrangement of previous experimental investigations to determine whether rectilinear motion provides a reasonable approximation to simulate the near seabed orbital particle paths in wind-generated waves. This assumption is based on the flattening of particle paths to ellipsoids with depth and ignores the small vertical velocity components near the seabed. Based on the hydrodynamic forces calculated numerically using a validated Computational Fluid Dynamics (CFD) model for rectilinear and orbital wave modelling it is concluded that pipeline stabilisation requirements calculated in accordance with the DNV-RP-F109 absolute lateral static stability design method and rectilinear wave motion assumption are conservative. It is also concluded that the hydrodynamic force asymmetry in favour of the reverse half wave cycle caused by the vertical velocity components in orbital wave conditions requires further consideration to determine the implication for dynamic lateral stability design methods.

Oil Scoop Simulation and Analysis Using CFD and SPH

2016 ◽  
Author(s):  
Evgenia Korsukova ◽  
Arno Kruisbrink ◽  
Hervé Morvan ◽  
Paloma Paleo Cageao ◽  
Kathy Simmons
Keyword(s):  
Free Surface ◽  
Coming Out ◽  
High Speed ◽  
Direct Injection ◽  
Three Dimensional ◽  
Flow Simulation ◽  
Particle Collision ◽  
Engine Cooling ◽  
Comparison Of The Results ◽  
Oil Jet

The process of rotating scoops capturing oil coming out of a stationary jet nozzle was simulated with CFD (Computational Fluid Dynamics) and SPH (Smoothed Particles Hydrodynamics). The aim was to determine the efficiency of the oil capture, and the effects of varying parameters such as angular velocity of the scoops, the speed and direction of the oil jet and arrangement of the oil jets (in case of more than one jet). This configuration is found in engine cooling and/or lubricating systems: where oil scoops are used to deliver the oil to the places where direct injection is not possible. In CFD both two- and three-dimensional geometries were used; the models were then run using the Volume of Fluid method with the SST k-ω model. SPH is a meshless Lagrangian method for flow simulation, where the fluid is represented by particles. In addition to the conventional SPH formulation, three main highlights were introduced in the current work: the rotating ghost particles (representing the scoops), the particle collision model (Korzilius et al., 2014) and source and sink particles (representing the oil coming out from the nozzle and captured at the scoops respectively). The simulations allowed for the observation of the free surface of the oil jet (before, during, and after cutting of the jet by the blade), the pressure and velocity fields for the air and oil, and the efficiency of the system, defined as the ratio of oil outflow (via scoops) and inflow. This is a comparative study between CFD and SPH, where SPH is explored for a lubrication of a high-speed rotating component. The results of CFD and SPH, in particular the oil free surface and the efficiency, were then compared and validated with experimental results, demonstrating good agreement. The setup and comparison of the results obtained with the described techniques are presented in this work.

scholarly journals Simulation of the pump-battery power supply control system based on the unloading machine

2020 ◽  
Vol 164 ◽  
pp. 01004 ◽  
Author(s):  
Alexander Rybak ◽  
I Tsibriy
Keyword(s):  
Control System ◽  
Numerical Experiment ◽  
Power Supply ◽  
Operation Mode ◽  
Power Source ◽  
Design Parameters ◽  
Hydraulic Systems ◽  
Original Design ◽  
Battery Power ◽  
Functional Features

The aim of this article is to create a control system for a constant hydraulic power source pressure, a pump -battery power source equipped with an original design of the hydraulic pump discharge machine that provides relay switching of its operation mode. This aim is achieved by using a simulation method based on the application of volumetric stiffness theory of hydraulic systems and their elements. As a result of a numerical experiment conducted by solving the equations that make up the mathematical model of power supply, its main technical characteristics and the influence of its main design parameters on its functional features and operational properties are obtained. The obtained results showed that by changing the various design parameters of unloading machine, it is possible not only to change the upper (maximum) and lower (minimum) values of the battery charging pressure, but also to adjust their difference depending on the requirements for the power source. The main result of this study is that as a result of a numerical experiment, it is proved that the unloading machine provides a clear relay switching of the pump operation mode from unloading to operating mode and Vice versa. The identified properties make a very promising use of a pump -battery power source in the hydraulic systems of mobile machines and process equipment.

Dynamic characteristics of water-lubricated journal bearings

2019 ◽  
Vol 20 (4) ◽  
pp. 404
Author(s):  
Qiang Li ◽  
Shuo Zhang ◽  
Yujun Wang ◽  
Weiwei Xu ◽  
Zengli Wang ◽  
...  
Keyword(s):  
Dynamic Characteristics ◽  
Hydrodynamic Force ◽  
Hydrodynamic Forces ◽  
Journal Bearings ◽  
Dynamic Responses ◽  
Force Model ◽  
Ecological Awareness ◽  
Mesh Movement ◽  
Linear And Nonlinear ◽  
Structured Mesh

The increasing ecological awareness and stringent requirements for environmental protection have led to the development of water lubricated journal bearings. For the investigation of water-lubricated journal bearings, a new structured mesh movement algorithm for the CFD model is developed and based on this method, the nonlinear transient hydrodynamic force model is established. Then, with consideration of velocity perturbation, a method to determine dynamic coefficients and linear hydrodynamic forces is promoted. After validation of static equilibrium position and stiffness coefficients, a comparative linear and nonlinear hydrodynamic force analysis of multiple grooves water-lubricated journal bearings (MGWJBs) is conducted. The calculation results indicate that the structured mesh movement algorithm is suitable for the dynamic characteristics investigation of water-lubricated journal bearings. And the comparative study shows that there is a considerable difference between the linear and nonlinear hydrodynamic forces of MGWJBs. Further investigation should be carried to evaluate the dynamic responses of rotor supported by MGWJBs under difference force models.

Computational and experimental study of the stress state of the connecting rod of the opposed compressor to assess the probability of failure-free operation

2020 ◽  
Vol 86 (5) ◽  
pp. 52-58
Author(s):  
I. M. Petrova ◽  
M. A. Filimonov
Keyword(s):  
Experimental Data ◽  
Experimental Study ◽  
Stress State ◽  
Numerical Experiment ◽  
Field Experiments ◽  
Fatigue Cracks ◽  
Tangential Force ◽  
Experimental Studies ◽  
Connecting Rod ◽  
Comparison Of The Results

Fatigue cracks in the piston heads of the connecting rods of opposed compressors can occasionally develop in service. A study of the loading of the connecting rods of the compressors operating in chemical production was carried out to assess the probability of their failure-free operation. Since the experimental study of stresses acting in large structural elements is rather difficult, the study of the stress state was carried out using computational methods with subsequent comparison of the results with the experimental data. When loading the connecting rod, there is an area affected by the distributed load and another area with a gap between the cylindrical surfaces where the contact pressure is absent. The forces acting on the boundary of the contact areas and the gap of the finger with the connecting rod bore are determined: the radial force N, tangential force Q and bending moment M. N and Q are considered functions of the contact angle α. Using numerical experiments, we determined the stresses in the zone from the angle α corresponding to the end of the contact zone to the angle of transition of the head in the shank of connecting rod in conditions of varied operational loads and gaps in the connecting rod — finger coupling. The values and character of changes in the loads affecting the crank mechanism of the compressor during operation are determined experimentally. The distribution of stresses in the sections of the connecting rod and the most loaded cross-sections are specified. the results of the numerical experiment are compared with the experimental data. Comparison of the results of numerical and field experiments has shown that the numerical experiment provides the similar assessment of the stress distribution, moreover, the numerical experiment allows us to estimate the simultaneous effect of both loads and gaps on the stress growth which is almost impossible to be determined by experimental studies.

Deployment of FACTS Controllers in Solving Power System Network Problems: A Review

2020 ◽  
Vol 51 ◽  
pp. 147-175
Author(s):  
Babatunde Olusegun Adewolu ◽  
Akshay Kumar Saha
Keyword(s):  
Power Flow ◽  
Economic Benefits ◽  
Stability Control ◽  
System Stability ◽  
Power Network ◽  
Network Systems ◽  
Control Power ◽  
Facts Controllers ◽  
Flexible Alternating Current Transmission ◽  
Vantage Points

Flexible alternating current transmission systems (FACTS) deployments and applications are on the increase in modern day power network systems because of their advantages over conventional ways of power network physical expansion. Therefore, a comprehensive review of FACTS controllers with their various applications is carried out in this paper. Formation of different applications and advantages of FACTS devices into voltage control, power flow control, system stability control, power quality control, and economic benefits as inferred from the literatures is among the vantage points of this presentation. FACTS background alongside different techniques of deployments, leading to various applications and performance of these devices, hitherto organized structurally based on target objectives are also explored, presented and discussed. Summarily, this study provides an overview of the background, topological structures, deployment techniques and cutting-edge utilization of FACTS controllers, with a view to acquainting power players, electrical engineers, network designers as well as researchers, with the trends in the development, status and future direction of FACTS applications. Convincingly, the content of this article will benefit all the stakeholders in the area of FACTS deployments and utilizations.

An Investigation of Dynamic Pulse Buckling of Thick Rings

1992 ◽  
Vol 59 (3) ◽  
pp. 615-621 ◽  
Author(s):  
N. G. Pegg
Keyword(s):  
Finite Element ◽  
Analytical Solution ◽  
Numerical Solutions ◽  
Nonlinear Finite Element ◽  
Finite Element Analyses ◽  
Elastoplastic Behavior ◽  
Impulse Load ◽  
Pulse Buckling ◽  
Comparison Of The Results ◽  
Dynamic Pulse

The occurrence of dynamic buckling of thick rings responding to an impulse load is investigated by analytical and numerical solutions to the equation of motion and by nonlinear finite element analyses. An extension to the linearized analytical solution is made using a finite difference scheme which incorporates a nonlinear moment-curvature relationship to model the effects of elastoplastic behavior and strain-rate reversal on the buckle formation. The finite element solution to the problem is formulated with the nonlinear code, ADINA. A comparison of the results shows that the numerical solutions (and, in particular, the ADINA solution) predict a significant reduction in the amplitude of buckling response and an increase in the predominant wavelength of response with time, in comparison to the linear analytical solution. A limited comparison to published experimental results of dynamic pulse buckling of thick rings is also given.

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