scholarly journals ABOUT THE PARAMETERS OF THE WORKING FLUID FOR UNDERSEA HYDRAULIC SYSTEMS

2019 ◽  
Vol 2 ◽  
pp. 14-32
Author(s):  
N.I. Sidnyaev ◽  
◽  
M.A. Berezhnova ◽  
Keyword(s):  
Working Fluid ◽  
Hydraulic Systems

Calculation of a closed hydraulic volumetric system

2021 ◽  
pp. 27-30
Author(s):  
Keyword(s):  
Power Plant ◽  
Wind Power ◽  
Hydraulic System ◽  
Working Fluid ◽  
Wind Power Plant ◽  
Hydraulic Systems ◽  
Hydraulic Motor ◽  
Hydraulic Pump ◽  
Oil Pump ◽  
Selection Of

An algorithm is proposed for calculating a closed volumetric hydraulic pump-hydraulic motor system using the example of the hydraulic system of a wind power plant, based on the calculation of the hydraulic systems of mobile machines. The main characteristics of the system components, the selection of initial data for the calculation, working fluid and diameters of hydraulic lines are analyzed. Keywords: hydraulic system, energy, fluid, oil, pump, motor, renewable energy source, wind power plant, machine. [email protected]

THE USE OF HYDRAULIC “LONG” LINES IN MODERN SUBSEA PRODUCTION FACILITIES

2020 ◽  
pp. 43-51
Author(s):  
K. A. Trukhanov
Keyword(s):  
Mathematical Model ◽  
Working Fluid ◽  
Hydraulic Systems ◽  
Signal Attenuation ◽  
Friction Resistance ◽  
Distributed Parameters ◽  
Long Line ◽  
Pump Flow Rate ◽  
Modern Application ◽  
Mathematical Relationships

Describes and provides a brief description of the modern application of hydraulic “long” lines in a subsea production facility. The necessity and relevance of developing a mathematical model that allows us to predict and carry out practical calculations of ongoing processes in hydraulic “long” lines, spending the minimum amount of time and resources on this, is shown. In the article are provided general provisions and basic mathematical relationships for performing calculations and modeling unsteady processes in hydraulic lines with distributed parameters. Boundary conditions are given that make it possible to obtain a closed system of equations representing a mathematical model of hydraulic “long” lines. The scientific novelty of the results presented in the article is that the main criteria necessary for the design and operation of equipment containing hydraulic “long” lines were obtained and presented. Among which it is especially necessary to note, dependences for the unsteady coefficient of hydraulic friction resistance of the pipe λ. Criteria are also given for determining the amplitude of signal attenuation in the case of using a hydraulic “long” line as a line for transmitting information, as well as a criterion that allows to determine the minimum pump flow rate to ensure a given level of purity of the working fluid during operation and maintenance of equipment with hydraulic “long” lines, which It is especially important and relevant in practice for the selection of equipment and determine the minimum required power. The content of the article is interest to specialists involved in the development of hydraulic systems with hydraulic “long” lines.

Micro Surface Shaping for the High-Pressure Operation of Piston Machines With Water as a Working Fluid

2015 ◽  
Author(s):  
Meike H. Ernst ◽  
Monika Ivantysynova
Keyword(s):  
High Pressure ◽  
High Pressures ◽  
Working Fluid ◽  
Hydraulic Systems ◽  
Machinery Construction ◽  
Pressure Buildup ◽  
Piston Cylinder ◽  
Low Viscosity ◽  
Load Carrying ◽  
Surface Shaping

Oil is the main working fluid used in the hydraulics industry today — but water is nonflammable, environmentally friendly and cheap: it is the better choice of working fluid for hydraulic systems. However, there is one caveat. Water’s extremely low viscosity undermines its ability to carry load. In forest machinery, construction machinery, and aircraft systems, today’s hydraulic circuits have high operating pressures, with typical values between 300 and 420 bar. These high pressures create the need for high load-carrying abilities in the fluid films of the tribological interfaces of pumps and motors. The most challenging of these interfaces is the piston-cylinder interface of swashplate type piston machines, because the fluid must balance the entire piston side load created in this design. The low viscosity of the water turns preventing metal-to-metal contact into quite a challenge. Fortunately, an understanding of how pressure builds and shifts about in these piston-cylinder lubrication interfaces, coupled with some clever micro surface shaping, can allow engineers to drastically increase the load-carrying ability of water. As part of this research, numerous different micro surface shaping design ideas have been simulated using a highly advanced non-isothermal multi-physics model developed at the Maha Fluid Power Research Center. The model calculates leakage, power losses, film thickness and pressure buildup in the piston-cylinder interface over the course of one shaft revolution. The results allow for the comparison of different surface shapes, such as axial sine waves along the piston, or a barrel-shaped piston profile. This paper elucidates the effect of those surface profiles on pressure buildup, leakage, and torque loss in the piston-cylinder interface of an axial piston pump running at high pressure with water as the lubricant.

scholarly journals RELAP5-3D Code Includes ATHENA Features and Models

2006 ◽  
Author(s):  
Richard A. Riemke ◽  
Cliff B. Davis ◽  
Richard R. Schultz
Keyword(s):  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Gas Phase ◽  
Molten Salts ◽  
Working Fluid ◽  
Hydraulic Systems ◽  
Sodium Potassium ◽  
Working Fluids ◽  
Noncondensable Gases ◽  
Magnetohydrodynamic Model

Version 2.3 of the RELAP5-3D computer program includes all features and models previously available only in the ATHENA version of the code. These include the addition of new working fluids (i.e., ammonia, blood, carbon dioxide, glycerol, helium, hydrogen, lead-bismuth, lithium, lithium-lead, nitrogen, potassium, sodium, and sodium-potassium) and a magnetohydrodynamic model that expands the capability of the code to model many more thermal-hydraulic systems. In addition to the new working fluids along with the standard working fluid water, one or more noncondensable gases (e.g., air, argon, carbon dioxide, carbon monoxide, helium, hydrogen, krypton, nitrogen, oxygen, sf6, xenon) can be specified as part of the vapor/gas phase of the working fluid. These noncondensable gases were in previous versions of RELAP5-3D. Recently four molten salts have been added as working fluids to RELAP5-3D Version 2.4, which has had limited release. These molten salts will be in RELAP5-3D Version 2.5, which will have a general release like RELAP5-3D Version 2.3. Applications that use these new features and models are discussed in this paper.

scholarly journals Alternative rapeseed based oil fluid for hydraulic systems of tractors

2021 ◽  
Vol 37 ◽  
pp. 00030
Author(s):  
Alexander P. Bychenin ◽  
Oleg S. Volodko ◽  
Denis N. Bazhutov
Keyword(s):  
Vegetable Oils ◽  
Tribological Properties ◽  
Rapeseed Oil ◽  
Alternative Fuels ◽  
Working Fluid ◽  
Hydraulic Systems ◽  
Agricultural Machinery ◽  
Laboratory Findings ◽  
Hydraulic Oil ◽  
Mineral Oils

The paper analyzes the main applications of alternative fuels and lubricants in automotive vehicles, considers the possibility of using vegetable oils as a working fluid for hydraulic systems of agricultural machinery. Based on the laboratory findings, it states the ways to improve a lubrication formula based on rapeseed oil. The formula is proven to be optimal if it includes 88.9% rapeseed oil + 3.7% D-11 + 3.2% EFO + 4.197% graphite + 0.003% MS-200A, which is superior in tribological properties to MGE-46V hydraulic oil, and can be recommended for use in hydraulic systems of agricultural machinery as an alternative to mineral oils.

scholarly journals SELF-CLEANING FILTER FOR CLOSED HYDROSYSTEMS OF AGRICULTURAL EQUIPMENT

2021 ◽  
Vol 295 (2) ◽  
pp. 130-138
Author(s):  
M. STADNIK ◽  
◽  
А. VIDMYSH ◽  
S. SHARGORODSKIY ◽  
V. RUTKEVYCH ◽  
...  
Keyword(s):  
Pressure Drop ◽  
Pressure Pulsation ◽  
Experimental Studies ◽  
Hydraulic Drive ◽  
Operating Mode ◽  
Working Fluid ◽  
Hydraulic Systems ◽  
Agricultural Equipment ◽  
Self Cleaning ◽  
Special Stand

The issue of increasing the reliability and durability of hydraulic units of closed hydraulic systems of agricultural equipment is considered, due to better cleaning of the working fluid by filtration units. The design of a self-cleaning filter with hydraulic automatic control of backwashing of slotted filtration elements with a counterflow of the working fluid is proposed. A special stand has been developed for simulating the operation of a self-cleaning filter of closed hydraulic systems of agricultural equipment. Experimental studies on a special stand confirmed the efficiency of the proposed design and made it possible to identify its main advantages in comparison with domestic and foreign counterparts. Based on the analysis of transient processes with increased pressure pulsation of agricultural equipment of a closed hydraulic drive, the actual pressure drop at which automatic flushing is triggered was established, compared with the calculated one, in which it was impossible to take into account such real factors as friction in the sealing units, the characteristics of the springs, distortions, tightness of valve pairs, fluctuations in dimensional chains. The most optimal operating mode of auto-washing equipment with a choke diameter of 1.0 mm has been determined. The auto-washing equipment was switched on at a pressure drop of 1.5 MPa (15 atm) and in an improved mode – pressure pulsations with an amplitude of 2 MPa (20 atm) when the auto-wash was turned off decreased in time to 0.12 s. It is noted that the developed self-cleaning filter for closed hydraulic systems of agricultural equipment will improve the reliability and increase the service life of the elements of hydraulic units and the machine itself as a whole.

scholarly journals Visualization research on the influence of an ultrasonic degassing system on the operation of a hydraulic gear pump

2018 ◽  
Vol 211 ◽  
pp. 03005 ◽  
Author(s):  
Piotr Antoniak ◽  
Jarosław Stryczek ◽  
Michał Banaś ◽  
Oleksandr Lyhovskyi ◽  
Ihor Gryshko ◽  
...  
Keyword(s):  
High Speed ◽  
Theoretical Description ◽  
Working Fluid ◽  
Operating Parameters ◽  
Gear Pump ◽  
Hydraulic Systems ◽  
Chemical Methods ◽  
Physical Methods ◽  
Working Medium ◽  
Gear Pumps

Gear pumps make a group of the most popular hydraulic energy generators. Research and development works concerning those units have been going on for decades, and thanks to them gear pumps feature very good operating parameters. However, even well-designed gear pumps will not work properly if the physical properties of the working fluid are incorrect. One of such properties is compressibility of the fluid, which largely depends on the amount of gas dissolved in the medium. For this reason, the aim is to reduce the amount of gas dissolved in the working medium. It can be done using both chemical and physical methods. Because chemical methods can affect the chemical composition of the working fluid, it is the physical methods that are usually used in hydraulic systems. This paper presents preliminary visualization research into the influence of an ultrasonic degassing system on the operation of a hydraulic gear pump. Apart from that, operation of such a system and its theoretical impact on the work of the gear pump is discussed Experimental study, using a high-speed camera, was carried out in order to verify the theoretical description.

scholarly journals ОСОБЛИВОСТІ ТЕРМОІМПУЛЬСНОГО ОЧИЩЕННЯ ПОВЕРХОНЬ І КРОМОК ДЕТАЛЕЙ ВІД ЗАБРУДНЕНЬ ПІСЛЯ МЕХАНІЧНОЇ ОБРОБКИ

2018 ◽  
pp. 36-46
Author(s):  
Алексей Васильевич Лосев ◽  
Игорь Валерьевич Бычков ◽  
Вячеслав Викторович Коллеров ◽  
Анна Сергеевна Селезнева
Keyword(s):  
Experimental Studies ◽  
Cost Effective ◽  
Operating Conditions ◽  
Working Fluid ◽  
Body Parts ◽  
Hydraulic Systems ◽  
Cost Component ◽  
Internal Surfaces ◽  
And Control

The requirements for the quality of aviation technology are decisive in the creation of technological systems that ensure the industrial purity of products. But the cost component of the finishing and stripping technologies is also important, the value of which depends on the chosen method of removing liquids, for example, from hydraulic units of aircraft. Reliable and cost-effective manufacture of parts with specific geometric and technological properties is the main goal of industrial production. In a market economy, the production of competitive products is a necessity, and it is always the choice of a rational, stable price-quality ratio. The quality of engineering products is a multifactorial problem, depending on the complex of systemic organizational and technological measures. In the production of aircraft technology, quality assurance is associated with dependability and a guaranteed resource that is vital due to specific operating conditions. One of the most important measures to ensure the reliability and guaranteed life of aviation products is to ensure industrial cleanliness. Cleaning from microparticles, macro- and micro-hauler surfaces and edges of parts after mechanical types of processing is included in the complex of these measures. The most problematic is the cleaning of body parts with a complex configuration of external and internal surfaces. The need to remove liquids and other technological pollution is explained by functional, ergonomic and aesthetic reasons. If ergonomic and aesthetic factors do not affect the technical characteristics of products, then the functional ones are directly related to the operability of machines and mechanisms. Functional causes are the prevention of failures of hydraulic distribution and control devices, as well as the prevention of increased wear of critical parts occurring when friction pairs of solid metal particles enter the gaps, difficulties in assembling and positioning, reducing fatigue strength and so on. Burrs cause turbulence in the flow of gas or liquid, disrupting the flow uniformity. It is obvious that the mutually influencing processes occurring in the hydraulic systems of machines, in violation of working conditions, lead to an increase in negative phenomena. The peculiarity of the use of purification technologies is the need to remove liquids from 100% of the parts included in the autonomous system of mechanisms. If at least one detail is left untreated, then the working fluid, when in contact with contaminated surfaces, washes away these contaminants and spreads them throughout the system, while the most sensitive elements are damaged. The reasons for the need to clean the surface and edges of parts from technological contamination are given. A brief review of the results of modeling and research on the removal of burrs in the environment of detonating gas mixtures has been performed. The features of the thermopulse process are considered and the results of numerical and experimental studies are presented. A comparative analysis of the energy intensity of removing burrs of various metals is shown.

scholarly journals Inlet metering pump analysis and experimental evaluation with application for flow control

2017 ◽  
Author(s):  
◽  
Hasan H. Ali
Keyword(s):  
Control System ◽  
Theoretical Model ◽  
Specific Volume ◽  
Control Flow ◽  
Experimental Results ◽  
Working Fluid ◽  
Pump Efficiency ◽  
Hydraulic Systems ◽  
Velocity Control ◽  
Pump Design

Axial piston pumps with variable volumetric displacement are often used to control flow and pressure in hydraulic systems. The displacement control mechanism in these pumps occupies significant space and accounts for significant cost in the pump design. Fixed displacement pumps have lower cost and a more compact design but suffer from significant energy consumption disadvantage due to the need for flow and pressure control by throttling flow and bypassing unused flow to pressures below the discharge pressure. An inlet metering valve (IMV) controlled pump marks a recent development in pumping technology for hydraulic systems. In this design, an inlet metering valve restricts inlet flow reducing inlet pressure so that the specific volume of the fluid is increased as it enters a fixed displacement pump. By altering the specific volume of the working fluid, the inlet metering valve permits precise control over the pump discharge flow. This study presents a theoretical model for inlet metering pump efficiency. The work considers additional sources of energy loss unique to the inlet metering system. Experimental results associated with inlet metering pump efficiency are presented. A comparison of the theoretical model and the experimental results is also included. It is determined that the current efficiency model accurately predicts efficiencies determined using experimental data. In addition, a velocity control system is considered which utilizes the inlet metering valve controlled pump. The stability and the performance of the velocity control system were studied for the open-loop and the closed-loop with a PID, H[infinity symbol], and a two degrees of freedom controllers. The simulation showed that the velocity control system is stable and has good performance characteristics.

scholarly journals PRINCIPLES OF CONSTRUCTION OF THE GENERALIZED MATHEMATICAL MODEL OF THE HYDRAULIC EXTINGUISHER OF OSCILLATIONS OF THE PASSENGER CAR

2021 ◽  
Vol 1 (38) ◽  
pp. 173-184
Author(s):  
I. Shcherbyna
Keyword(s):  
Mathematical Model ◽  
Operating Conditions ◽  
Working Fluid ◽  
Operating Parameters ◽  
Hydraulic Systems ◽  
Passenger Cars ◽  
Passenger Car ◽  
Periodic Movement ◽  
Depth Analysis ◽  
The Impact

The study of the processes associated with the use of working fluids in the elements of hydraulic drives was preceded by studies of the unsteady periodic movement of the working fluid in the pipelines of hydraulic systems. Such processes take place in hydraulic drives and their elements, and are associated with the compressibility of the working fluid. The stability of the operation of hydraulic valves, which are supplied to hydraulic systems in order to maintain, within the required limits, pressures or flow rates, is also largely predetermined by non-stationary hydro mechanical processes occurring in the pipelines of these systems, channels and chambers of hydraulic devices. The peculiarities of the working processes of passive vibration dampers of passenger cars include the interaction of the working fluid with moving parts and its flow through the channels and through the calibrated holes with local artificial resistance. For in-depth analysis of changes in operating parameters, it is necessary to use a mathematical model that should reflect the processes that occur during the operation of the hydraulic device. In the presented article the generalized mathematical model of the hydraulic damper of fluctuations of the passenger car of the НЦ-1100 type is developed. This model takes into account the special operating conditions of the hydraulic shock absorber, which allows you to study the impact of operating parameters on the performance of the device.

Sign in / Sign up

Export Citation Format

Share Document