scholarly journals The Influence of Water and Mineral Oil On Volumetric Losses in a Hydraulic Motor

2017 ◽  
Vol 24 (s1) ◽  
pp. 213-223 ◽  
Author(s):  
Pawel Śliwiński
Keyword(s):  
Mathematical Model ◽  
Rotational Speed ◽  
Experimental Studies ◽  
Experimental Tests ◽  
Mineral Oil ◽  
Hydraulic Motor ◽  
Small Constant ◽  
Influence Of Water ◽  
The Difference ◽  
Lubricating Properties

Abstract In this paper volumetric losses in hydraulic motor supplied with water and mineral oil (two liquids having significantly different viscosity and lubricating properties) are described and compared. The experimental tests were conducted using an innovative hydraulic satellite motor, that is dedicated to work with different liquids, including water. The sources of leaks in this motor are also characterized and described. On this basis, a mathematical model of volumetric losses and model of effective rotational speed have been developed and presented. The results of calculation of volumetric losses according to the model are compared with the results of experiment. It was found that the difference is not more than 20%. Furthermore, it has been demonstrated that this model well describes in both the volumetric losses in the motor supplied with water and oil. Experimental studies have shown that the volumetric losses in the motor supplied with water are even three times greater than the volumetric losses in the motor supplied with oil. It has been shown, that in a small constant stream of water the speed of the motor is reduced even by half in comparison of speed of motor supplied with the same stream of oil.

scholarly journals The Influence of Water and Mineral Oil on Mechanical Losses in a Hydraulic Motor for Offshore and Marine Applications

2020 ◽  
Vol 27 (2) ◽  
pp. 125-135 ◽  
Author(s):  
Paweł Śliwiński
Keyword(s):  
Mathematical Model ◽  
High Speed ◽  
Experimental Studies ◽  
Experimental Tests ◽  
Mineral Oil ◽  
Hydraulic Motor ◽  
Influence Of Water ◽  
Marine Applications ◽  
The One ◽  
The Mathematical Model

AbstractIn this paper, mechanical losses in a hydraulic motor supplied with water and mineral oil (two liquids having significantly different viscosity and lubricating properties) are described and compared. The experimental tests were conducted using a special design (prototype) of a hydraulic satellite motor. The design of the satellite motor is presented. This motor was developed to supply both with water and mineral oil and features a non-circular tooth working mechanism. The paper also characterizes sources of mechanical losses in this motor. On this basis, a mathematical model of these losses has been developed and presented. The results of calculation of mechanical losses according to the model are compared with the experimental results. Experimental studies have shown that the mechanical losses in the motor supplied with water are 2.8 times greater than those in the motor supplied with oil. The work demonstrates that the mechanical losses in both the motor supplied with water and the one supplied with oil are described well by the mathematical model. It has been found that for the loaded motor working at high speed, the simulation results differ from experimental ones by no more than 3% for oil and 4% for water.

scholarly journals The Influence of Water and Mineral Oil on Volumetric Losses in the Displacement Pump for Offshore and Marine Applications

2019 ◽  
Vol 26 (2) ◽  
pp. 173-182 ◽  
Author(s):  
Paweł Śliwiński
Keyword(s):  
Mathematical Model ◽  
Experimental Studies ◽  
Experimental Tests ◽  
Mineral Oil ◽  
Water Pump ◽  
Positive Displacement ◽  
Oil Pump ◽  
Influence Of Water ◽  
Displacement Pump ◽  
Marine Applications

Abstract In this paper, volumetric losses in a positive displacement pump supplied with water and mineral oil are described and compared. The experimental tests were conducted using a prototype of a satellite pump (with a non-circular tooth working mechanism). In this paper, the sources of volumetric losses in this pump are characterized. On this basis, a mathematical model of these losses has been presented. The results of the calculation of volumetric losses according to the model are compared with the results of the experiment. Experimental studies have shown that the volumetric losses in the water pump are even 3.2 times greater than the volumetric losses in the oil pump. It has been demonstrated that the mathematical model describing the volumetric losses both in the water pump and in the oil pump is quite good. It has been found that the results from the loaded pump simulation (at ∆p=25MPa and ant n=1500rpm) differ from the results of the experiment by no more than 5% both for oil and water.

scholarly journals The Influence of Water and Mineral Oil On Mechanical Losses in the Displacement Pump for Offshore and Marine Applications

2018 ◽  
Vol 25 (s1) ◽  
pp. 178-188 ◽  
Author(s):  
Paweł Śliwiński
Keyword(s):  
Mathematical Model ◽  
Experimental Studies ◽  
Experimental Tests ◽  
Mineral Oil ◽  
Water Pump ◽  
Positive Displacement ◽  
Oil Pump ◽  
Influence Of Water ◽  
Displacement Pump ◽  
Marine Applications

Abstract In this paper mechanical losses in a positive displacement pump supplied with water and mineral oil (two liquids having significantly different viscosity and lubricating properties) are described and compared. The experimental tests were conducted by using a prototype satellite pump of a special design. The design of the satellite pump is presented in the article. The pump features and a non-circular tooth working mechanism was developed to work with both water and mineral oil. The sources of mechanical losses in such pump are also characterized in this paper. On this basis, a mathematical model of the losses has been developed and presented. The results of the calculation of mechanical losses according to the model are compared with the results of the experiment. The experimental studies have shown that the mechanical losses in the water pump are even 2.8 times greater than those in the oil pump. It has been demonstrated that the mathematical model well describes the mechanical losses both in the water pump and the oil pump. It has been found that the results from the loaded pump simulation (at Δp=25MPa) differ from the results of the experiment by no more than 5% both for oil and water.

scholarly journals Methods of Determining Pressure Drop in Internal Channels of a Hydraulic Motor

Energies ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5669
Author(s):  
Pawel Sliwinski ◽  
Piotr Patrosz
Keyword(s):  
Pressure Drop ◽  
Experimental Studies ◽  
Experimental Tests ◽  
High Flow ◽  
Low Flow ◽  
Hydraulic Motor ◽  
Flow Rates ◽  
Pressure Losses ◽  
Face To Face ◽  
New Methods

In this paper, new methods for determining the pressure drop in internal channels of a hydraulic motor are proposed and described. Mathematical models of pressure losses in internal channels have also been described. Experimental tests of the satellite motor were carried out according to one of the proposed methods. The tests were carried out for two liquids, i.e., water and mineral oil. Experimental studies have shown that at a high flow rate in the motor supplied with water the pressure losses are a dozen or so percent greater than in the motor supplied with oil. However, at low flow rates is the inverse, that is, the pressure losses in the motor supplied with water are about ten percent lower than in the motor supplied with oil. The CFD calculation of the pressure drop in the internal channel of the motor was also conducted. It was assumed that holes in the commutation unit plate are placed face to face and that the liquid did not cause changes in the working chambers’ volume. In this way, it has been proven that those simplified assumptions can have up to a 50% difference in relation to the experimental tests.

scholarly journals EXPERIMENTAL STUDIES OF A TWO-GRADE CHOPPER OF BEETS

2019 ◽  
Vol 14 (2) ◽  
pp. 100-105
Author(s):  
Динар Исмагилов ◽  
Dinar Ismagilov ◽  
Марат Калимуллин ◽  
Marat Kalimullin ◽  
Ринат Абдрахманов ◽  
...  
Keyword(s):  
Rotational Speed ◽  
Experimental Studies ◽  
Cross Sectional ◽  
Flexible Working ◽  
Hydraulic Motors ◽  
Working Element ◽  
The Cross ◽  
The Difference ◽  
The Republic ◽  
Cutting Height

The two-grade rotary chopper BIR-2 of root and tuber crops with flexible working elements is designed to remove the beets of vegetable leaves before or during the harvest of carrots. It is proposed to use it together with an undermining machine in an aggregate with a tractor of the 1.4 kN class of thrust with a front and rear hitch. In this case, the chopper of beets is hung on the front hitch of the power means, and the working units are driven in rotation by hydraulic motors, which allows the two unitized devices to operate independently of each other. Laboratory studies of the effect of rotational speed, type and diameter of the cross section of work items on the amplitude of their oscillations were carried out on the soil plots Kazan State Agrarian University. Several types of work items were used in the experiments: a rubberized metal cable, a rubber-fabric element, a fishing line. The approbation was carried out when removing the tops of carrots. At this stage of experimental studies, the rotational speed of the working unit was 700 min-1, and the onward speed was 2.5 m/sec. Later, for the experiments, the plasticine pins were made, using which, with the necessary accuracy, the lower and upper points of contact of the working element can be determined, which, in turn, makes it possible to calculate the amplitude of transverse oscillations as the difference between these points. The rotational speed of the working elements at this stage varied from 500 to 900 min-1, the cross-sectional diameter - from 5 to 7 mm. According to the test results, the most rational diameter of the working element, which is equal to 5.5 mm, was determined, the required cutting height of the carrot tops in accordance with agrotechnical requirements, which is 0 ... 20 mm at a frequency of rotation of the working elements 800 min-1. According to the testing results of the developed unit under production conditions, which were carried out in JSC “Kyrlay” of the Republic of Tatarstan, the rational speed of the unit movement was chosen, which amounted to 3.3 m/sec.

Numerical Study of the Acoustic Efficiency of Sound-Absorbing Structures with Resonators of Various Forms

2018 ◽  
Vol 931 ◽  
pp. 158-163 ◽  
Author(s):  
Pavel V. Pisarev ◽  
Aleksandr N. Anoshkin ◽  
Karina A. Maksimova
Keyword(s):  
Mathematical Model ◽  
Mathematical Models ◽  
Numerical Solution ◽  
Numerical Experiments ◽  
Numerical Study ◽  
Experimental Studies ◽  
Acoustic Properties ◽  
Acoustic Characteristics ◽  
The Difference ◽  
Comparison Of The Results

The present work is devoted to a numerical study of the acoustic characteristics of cubic and folded resonators of sound-absorbing structures (SAS). In the process of work, a physical statement of the problem and a mathematical model for predicting the effective acoustic properties of the SAS cells are formulated. The validation of the developed mathematical models was carried out. During the comparison of the results of a numerical solution with experimental studies, the difference did not exceed 3%. Based on the results of the numerical experiments, the most effective resonators were identified, and recommendations on the design of the SAS on their basis were formulated.

Theoretical and Experimental Studies of the Steady State Performance of an Orbital Rotor Low-Speed High-Torque Hydraulic Motor

1996 ◽  
Vol 210 (6) ◽  
pp. 423-429 ◽  
Author(s):  
K Dasgupta ◽  
A Mukherjee ◽  
R Maiti
Keyword(s):  
Mathematical Model ◽  
Steady State ◽  
Experimental Studies ◽  
Engineering Systems ◽  
Hydraulic Motor ◽  
Low Speed ◽  
High Torque ◽  
Complex Variation ◽  
Structured Approach ◽  
Steady State Performance

In this paper the steady state performance of epitrochoid generated orbital ‘rotary piston machine’ (ROPIMA) type ‘low-speed high-torque’ (LSHT) hydrostatic unit has been studied. The complex variation of the volume of a chamber of such a machine with shaft rotation, along with the various flow and torque losses, demand a structured approach to arrive at its mathematical model. In conventional approaches the system morphology becomes obscured as the mathematical model is approached. Bondgraph provides a structured approach to model engineering systems in a simplified manner. A reduced Bondgraph model of the LSHT Orbital motor is made where the various losses are lumped in suitable resistive elements. The variations of the loss coefficients are identified. The predicted performance of the motor has been experimentally verified.

scholarly journals EXERGY ANALYSIS OF DOUBLE-CIRCUIT FLAT SOLAR COLLECTOR WITH THERMOSYPHON CIRCULATION

2019 ◽  
Vol 9 (3) ◽  
pp. 35-39
Author(s):  
Waldemar Wójcik ◽  
Maksat Kalimoldayev ◽  
Yedilkhan Amirgaliyev ◽  
Murat Kunelbayev ◽  
Aliya Kalizhanova ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Solar Collector ◽  
Exergy Analysis ◽  
Experimental Studies ◽  
Heating System ◽  
Solar Heating ◽  
The Sun ◽  
Entire System ◽  
Exergetic Efficiency ◽  
The Difference

In the present work, an exergy analysis was done of two-circuit flat solar collector with thermosiphon circulation. The article presents a mathematical model of energy and exergic analysis of flat solar collectors, as well as calculations of solar radiation efficiency, temperature, flow rate of the fluid, exergy rates and exergy loss rates are done. The significance of the results achieved is high, since experimental studies can detect inefficient components of the solar heating system. The exergetic efficiency of a dual-circuit flat solar collector with a thermosiphon circulation describes irreversibility of the process according to thermodynamic parameters. This is caused by a large the degree of overheating achieved at the end of the processes of compression and evaporation, which leads to large differences in heat exchange temperature based on the heat pump cycle. The exergy efficiency value for the entire system is 70. Maximum values energy efficiency and exergy at noon, 32.5% and 2.23%, respectively. The efficiency of exergy is 4%, and the highest the loss of exergy is the difference between the absorber plates and the sun, accounting for 52.86% of the total exergy rate.

EXPERIMENTAL STUDIES OF CAR PROPERTIES ON A PHYSICAL MODEL

2019 ◽  
pp. 10-16
Author(s):  
Oleksii Timkov ◽  
Dmytro Yashchenko ◽  
Volodymyr Bosenko
Keyword(s):  
Mathematical Model ◽  
Remote Control ◽  
Physical Model ◽  
Model Experiment ◽  
Experimental Studies ◽  
Electrical Energy ◽  
Short Term ◽  
Motor Current ◽  
Memory Card ◽  
The Mathematical Model

The article deals with the development of a physical model of a car equipped with measuring, recording and remote control equipment for experimental study of car properties. A detailed description of the design of the physical model and of the electronic modules used is given, links to application libraries and the code of the first part of the program for remote control of the model are given. Atmega microcontroller on the Arduino Uno platform was used to manage the model and register the parameters. When moving the car on the memory card saved such parameters as speed, voltage on the motor, current on the motor, the angle of the steered wheel, acceleration along three coordinate axes are recorded. Use of more powerful microcontrollers will allow to expand the list of the registered parameters of movement of the car. It is possible to measure the forces acting on the elements of the car and other parameters. In the future, it is planned to develop a mathematical model of motion of the car and check its adequacy in conducting experimental studies on maneuverability on the physical model. In addition, it is possible to conduct studies of stability and consumption of electrical energy. The physical model allows to quickly change geometric dimensions and mass parameters. In the study of highway trains, this approach will allow to investigate the various layout schemes of highway trains in the short term. It is possible to make two-axle road trains and saddle towed trains, three-way hitched trains of different layout. The results obtained will allow us to improve not only the mathematical model, but also the experimental physical model, and move on to further study the properties of hybrid road trains with an active trailer link. This approach allows to reduce material and time costs when researching the properties of cars and road trains. Keywords: car, physical model, experiment, road trains, sensor, remote control, maneuverability, stability.

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