Evaluation of Oil Viscosity Influence on Hydraulic Shock in Long Pipe

2014 ◽  
Vol 630 ◽  
pp. 85-90 ◽  
Author(s):  
Adam Bureček ◽  
Lumír Hružík ◽  
Martin Vašina
Keyword(s):  
Mathematical Model ◽  
Mathematical Simulation ◽  
Experimental Measurement ◽  
Hydraulic System ◽  
Pipe Wall ◽  
Hydraulic Shock ◽  
Oil Viscosity ◽  
Oil Flow ◽  
End Pressures ◽  
The Mathematical Model

This article is aimed at mathematical simulation and experimental measurement of dynamics of liquid and pipe wall during hydraulic shock. Liquid compressibility and hydraulic line elasticity are taken into account in this case. The mathematical model is created using Matlab SimHydraulics software. The long pipe is simulated by means of segmented pipe. Experimental measurement is performed on a hydraulic system, which consists of flow-controlled aggregate, long pipe and seat valve. The hydraulic shock is caused by step closing of the seat valve that is located at the pipe end. Pressures at the end of the long pipe, oil flow and temperature are experimentally measured.

scholarly journals INVESTIGATION OF HYDRODYNAMIC PROCESSES OF THE EXTINGUISHING DEVICE

Transport ◽  
2005 ◽  
Vol 20 (6) ◽  
pp. 219-224 ◽  
Author(s):  
Marijonas Bogdevicius ◽  
Vladimiras Suslavicius
Keyword(s):  
Mathematical Model ◽  
Mathematical Simulation ◽  
Hydraulic System ◽  
Hyperbolic Type ◽  
System Of Equations ◽  
Characteristics Method ◽  
Recoil Force ◽  
Hydrodynamic Processes ◽  
The Mathematical Model

The main aim of the investigation is to develop an approach to investigate hydrodynamic processes in the extinguishing device. The mathematical model of the extinguishing device is presented where the flow of fluid and gas and the interaction of liquid with gas are taken into account. The flow of fluid in a hydraulic system is described by a system of equations of a hyperbolic type which is solved by a characteristics method. An instance of the mathematical simulation of the activity extinguishing device is shown. The dependence of recoil force is obtained.

scholarly journals Simulation of parallel capacitance influence on the hydraulic system dynamics

2019 ◽  
Vol 213 ◽  
pp. 02016
Author(s):  
Dýrr Filip ◽  
Hružík Lumír ◽  
Bureček Adam ◽  
Brzezina Petr
Keyword(s):  
Mathematical Model ◽  
System Dynamics ◽  
Mathematical Simulation ◽  
Experimental Measurement ◽  
Hydraulic System ◽  
Stationary Flow ◽  
Pressure Response ◽  
Hydraulic Circuit

This paper covers with experimental measurement and mathematical simulation of parallel capacitance influence on pressure response for non-stationary flow. The hydraulic circuit for measuring required quantities, which are necessary to determine of parallel capacitance influence on the hydraulic system dynamics. A part of hydraulic system is a long pipe, in which the parallel capacitance created by hydraulic hose is connected. A non-stationary flow is caused by fast closing of the seat valve, which is situated at the end of long pipe. Mathematical model is realized and verified in Matlab SimScape Fluids software for this hydraulic system.

State Estimator of Flow as an Integrated Computational Method With the Feedback of Online Experimental Measurement

1997 ◽  
Vol 119 (4) ◽  
pp. 814-822 ◽  
Author(s):  
Toshiyuki Hayase ◽  
Satoru Hayashi
Keyword(s):  
Mathematical Model ◽  
Turbulent Flows ◽  
Experimental Measurement ◽  
Flow Simulation ◽  
Computational Method ◽  
Feedback Gain ◽  
State Estimator ◽  
Output Measurement ◽  
Real Flow ◽  
The Mathematical Model

This paper deals with a state estimator or simply an observer of flow field. The observer, being a fundamental concept in the control system theory, also has a potential in the analysis of flow related problems as an integrated computational method with the aid of experiment. In the framework of the observer, the state of physical flow is estimated from the mathematical model with the feedback of on-line experimental measurement. A SIMPLER based flow simulation algorithm is used as the mathematical model of the real flow and partial experimental measurement of flow is fed back to the boundary condition through the feedback controller. The existence of the feedback-loop essentially distinguishes the observer from ordinary flow simulations. Time variation of the computational result of the observer is expected to converge exactly to that of the physical flow in the whole flow domain even for unstable turbulent flows. A numerical experiment has been performed to confirm the validity of the proposed observer for a turbulent flow through a duct of square cross section. The physical flow to be estimated is modeled by a numerical solution. Appropriate choice for the proportional feedback gain of the observer results in accelerated convergence of the simulation by a factor of 0.012 and reduced error in estimation of the perturbation velocity by a factor of 0.6 in the whole domain or a factor of 0.3 behind the output measurement plane in comparison with the ordinary flow simulation without feedback.

scholarly journals Mathematical simulation of temperature influence on pressure drop at pump suction line

2019 ◽  
Vol 213 ◽  
pp. 02069
Author(s):  
Tomáš Polášek ◽  
Adam Bureček ◽  
Lumír Hružík
Keyword(s):  
Pressure Drop ◽  
Physical Properties ◽  
Mathematical Simulation ◽  
Flow Rate ◽  
Experimental Measurement ◽  
Mineral Oil ◽  
Temperature Influence ◽  
Oil Flow ◽  
Suction Line

The article is focused on mathematical simulation of the temperature influence on the pressure drop at the pump suction line. It is evaluated pressure drop depending on mineral oil flow rate. The courses of individual dependencies are determined by mathematical simulation using the ANSYS CFD computing software. The temperature affects significantly physical properties of the flowing mineral oil. In a paper is also described the experimental measurement of a mineral oil sample and determination of its physical properties depending on temperature.

scholarly journals Commissioning tests of the first hydro-generator of the Bajo de Mina HPP (Panama)

2020 ◽  
Vol 175 ◽  
pp. 05044
Author(s):  
Andrey Zuikov
Keyword(s):  
Mathematical Model ◽  
Free Surface ◽  
Empirical Data ◽  
Thrust Bearing ◽  
Third Party ◽  
Engineering Practice ◽  
Vertical Distributions ◽  
Oil Flow ◽  
The Mathematical Model

A mathematical model has been developed for calculating the distribution of azimuthal velocities and the shape of the free surface of oil in the compartments of an oil bath of a hydro-generator. The mathematical model of oil flow is verified by comparing the calculated radial-vertical distributions of normalized azimuthal velocities obtained on its basis with the free surface of the oil with the empirical data of third-party authors. The verification showed a good fit between the calculated and experimental distributions, which allows recommending the developed mathematical model for use in engineering practice. Calculations were carried out for the modes of the oil movement in the thrust bearing and the guide bearing of the hydro-generator of the Bajo de Mina HPP. Recommendations are made for the elimination of emergency modes associated with oil overflow through the fencing of the thrust bearing oil bath, which separate oil bath from the shaft of hydro-generator.

Performance Simulation and Analysis of the Progressive Distributor of the Oil-Air Lubrication by AMEsim

2013 ◽  
Vol 395-396 ◽  
pp. 1227-1232
Author(s):  
Qi Guo Sun ◽  
A Li Cai ◽  
Hong Bo Lv ◽  
Zheng Hui Zhou
Keyword(s):  
Mathematical Model ◽  
Friction Coefficient ◽  
Viscous Friction ◽  
Simulation Method ◽  
Analytic Method ◽  
Performance Simulation ◽  
Air Lubrication ◽  
Oil Flow ◽  
The Stability ◽  
The Mathematical Model

The mathematical model and the simulation model of the progressive distributor are established using an analytic method and AMEsim, a kind of simulation platform, respectively in this paper. The influences of the progressive structure, the viscous friction coefficient, the flow and pressure of the system and the size of throttle orifice on the performance of the progressive distributor are analyzed by the numerical simulation method. The results show that the fluctuations of the flow and pressure of the system are produced due to the overlapping motion of the three pistons, the oil-flow of the progressive distributor can be stabilized by choosing a reasonable viscous friction coefficient, and motion stability of the pistons of the progressive distributor, and the stability of the flow and pressure for the system are influenced by the size of throttle orifice. These conclusions will provide bases for the design of the oil-air lubricating system and the improvement of the structure of the progressive distributor.

Modeling and Stability Analysis of Hydraulic System for Wave Simulation

2013 ◽  
Vol 291-294 ◽  
pp. 1934-1939
Author(s):  
Jian Jun Peng ◽  
Yan Jun Liu ◽  
Yu Li ◽  
Ji Bin Liu
Keyword(s):  
Mathematical Model ◽  
Stability Analysis ◽  
Mathematical Models ◽  
Hydraulic System ◽  
Simulation System ◽  
Displacement Sensor ◽  
Schematic Diagram ◽  
Wave Simulation ◽  
The Stability ◽  
The Mathematical Model

This thesis put forward a hydraulic wave simulation system based on valve-controlled cylinder hydraulic system, which simulated wave movement on the land. The mathematical model of valve-controlled symmetric cylinder was deduced and the mathematical models of servo valve, displacement sensor and servo amplifier were established according to the schematic diagram of the hydraulic system designed, on the basis of which the mathematical model of hydraulic wave simulation system was obtained. Then the stability of the system was analyzed. The results indicated that the system was reliable.

Hydropneumatic Suspension Design

2003 ◽  
Author(s):  
Mauri´cio Baldi ◽  
Pable Siqueira Meirelles
Keyword(s):  
Mathematical Model ◽  
Hydraulic System ◽  
Experimental Validation ◽  
Crop Protection ◽  
Load Factor ◽  
Height Control ◽  
Suspension Parameters ◽  
High Dynamic ◽  
The Mathematical Model ◽  
Dynamic Load Factor

This study proposes a robust and cheap hydropneumatic suspension system for agricultural trailers used to spread crop protection. This kind of vehicle has a high dynamic load factor that increases the axles loads when it is in use and require a height control to assure the same spraying efficiency keeping constant the distance between the spray nozzles and the crop. As the tractor has its own hydraulic system, the hydropneumatic suspension conception take in account that height control will be done by the hydraulic fluid, being the mass of gas kept constant. A mathematical model of the hydropneumatic spring stiffness behavior was developed, as well as a methodology to define the suspension parameters. Experimental validation of the mathematical model was carried out through the use of a real agricultural trailer, equipped with a hydropneumatic suspension projected using the procedure presented, and tested in a hydropuls® road simulator.

Lubrication Analysis of a Rolling Piston Rotary Compressor: Part 2: Experimental Validation and Results

1994 ◽  
Vol 208 (2) ◽  
pp. 95-104
Author(s):  
S K Padhy
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Experimental Validation ◽  
Sensitivity Study ◽  
Rotary Compressor ◽  
Oil Flow ◽  
Different Dimensions ◽  
Rolling Piston ◽  
The Mathematical Model ◽  
Good Agreement

In this paper the experiments conducted for the measurement of oil flow in the rotary compressor are described. The experimental data are compared against the theoretical prediction from the mathematical model developed (1) and a good agreement is found. In addition, experimental data from previously published literature are also used to verify the mathematical model. A sensitivity study is carried out to predict the behaviour of the rotary compressor for the oil flow at different conditions and with different dimensions.

Simulation Analysis of Rotary Steering Pump-Control Hydraulic System

2013 ◽  
Vol 295-298 ◽  
pp. 1995-2000
Author(s):  
Guang Fu Chen ◽  
Xiao Xian Yao ◽  
Si Bao Li
Keyword(s):  
Mathematical Model ◽  
Comparative Analysis ◽  
Input Signal ◽  
Hydraulic System ◽  
Simulation Analysis ◽  
Harsh Environment ◽  
Hydraulic Systems ◽  
New Form ◽  
The Mathematical Model ◽  
Valve Control

The traditional valve control hydraulic systems have serious challenges in the harsh environment underground. The mathematical model of this new form of "motor - quantitative pump" controll system was established and simulated by using AMESIM software in this paper. According to the results of comparative analysis of the orifice parameters and the way to input signal, related parameters was determined, which can meet the characteristics of the system.

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