scholarly journals PROTECTION OF CENTRIFUGAL PUMPS FROM ABRASIVE WEAR USING A VACUUM HYDROCYCLONE

2020 ◽  
Vol 1 (383) ◽  
pp. 6-13
Author(s):  
Zh. K. Kassymbekov ◽  
O. V. Atamanova ◽  
K. K. Alimova ◽  
G. Zh. Kassymbekov
Keyword(s):  
Abrasive Wear ◽  
Pressure Gauge ◽  
Dynamic Test ◽  
Field Tests ◽  
Test Method ◽  
Design And Technology ◽  
Centrifugal Pumps ◽  
Borehole Pump ◽  
Suction Line ◽  
Pump Pressure

The design features of the existing design and technology for the protection of downhole pumps of the ECV type from abrasive wear during operation are considered and analyzed. Based on the analysis, a new method for capturing solid impurities on the suction line of a borehole pump of the ECV type using a pressure-vacuum hydrocyclone is proposed. It is specified that at field tests of a prototype of new installation technological process is estimated on the pressure-expense characteristic and technological-operational indicators according to requirements of GOST 6134-81 " pumps dynamic. Test method. " In this case, the flow rate of the base pump on water is determined by means of a turbine water meter mounted on a water-lifting pipe with a valve. The performance of the hydraulic elevator is established by the volumetric method, and the head in front of the valve of the pump pressure pipe using an approximate pressure gauge. It is established that the flow-pressure characteristics of the base submersible pump ECV are provided in full (water flow 60-70 m3/h, head - 110-118 m), overload on the electric motor is not detected (ammeter readings are within the permissible limits-68-71 amperes), the degree of water purification is 95-96%. It is noted that the implementation of a flexible packer device with slots and the presence on the surface of the second minihydrocyclone-thickener significantly improves the functioning of the adopted scheme of water treatment. It turned out that with this technology, the overload of the pump motor is reduced by cooling with water without mechanical impurities.

Effect of semi-open impeller side clearance on centrifugal pump cavitation inception

2018 ◽  
Vol 1 (2) ◽  
pp. 24-39
Author(s):  
A. Farid ◽  
A. Abou El-Azm Aly ◽  
H. Abdallah
Keyword(s):  
Centrifugal Pump ◽  
Static Pressure ◽  
Rotation Speed ◽  
Centrifugal Pumps ◽  
Severe Condition ◽  
Cavitation Inception ◽  
Total Input ◽  
Input Pressure ◽  
Pump Head ◽  
Pump Pressure

Cavitation in pumps is the most severe condition that centrifugal pumps can work in and is leading to a loss in their performance.  Herein, the effect of semi-open centrifugal pump side clearance on the inception of pump cavitation has been investigated.  The input pump pressure has been changed from 80 to 16 kPa and the pump side clearance has been changed from 1 mm to 3 mm at a rotation speed of 1500 rpm. It has been shown that as the total input pressure decreased; the static pressure inside the impeller is reduced while the total pressure in streamwise direction has been reduced, also the pump head is constant with the reduction of the total input pressure until the cavitation is reached. Head is reduced due to cavitation inception; the head is reduced in the case of a closed impeller with a percent of 1.5% while it is reduced with a percent of 0.5% for pump side clearance of 1mm, both are at a pressure of 20 kPa.   Results also showed that the cavitation inception in the pump had been affected and delayed with the increase of the pump side clearance; the cavitation has been noticed to occur at approximate pressures of 20 kPa for side clearance of 1mm, 18 kPa for side clearances of 2mm and 16 kPa for 3mm.

scholarly journals Concept and Realization of a Novel Test Method Using a Dynamic Test Stand for Detecting Persons by Sensor Systems on Autonomous Agricultural Robotics

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2315
Author(s):  
Christian Meltebrink ◽  
Tom Ströer ◽  
Benjamin Wegmann ◽  
Cornelia Weltzien ◽  
Arno Ruckelshausen
Keyword(s):  
Environmental Conditions ◽  
Dynamic Test ◽  
Test Methods ◽  
Test Stand ◽  
Human Detection ◽  
Test Method ◽  
Sensor Systems ◽  
Functional Safety ◽  
Agricultural Robots ◽  
Agricultural Robotics

As an essential part for the development of autonomous agricultural robotics, the functional safety of autonomous agricultural machines is largely based on the functionality and robustness of non-contact sensor systems for human protection. This article presents a new step in the development of autonomous agricultural machine with a concept and the realization of a novel test method using a dynamic test stand on an agricultural farm in outdoor areas. With this test method, commercially available sensor systems are tested in a long-term test around the clock for 365 days a year and 24 h a day on a dynamic test stand in continuous outdoor use. A test over a longer period of time is needed to test as much as possible all occurring environmental conditions. This test is determined by the naturally occurring environmental conditions. This fact corresponds to the reality of unpredictable/determinable environmental conditions in the field and makes the test method and test stand so unique. The focus of the developed test methods is on creating own real environment detection areas (REDAs) for each sensor system, which can be used to compare and evaluate the autonomous human detection of the sensor systems for the functional safety of autonomous agricultural robots with a humanoid test target. Sensor manufacturers from industry and the automotive sector provide their sensor systems to have their sensors tested in cooperation with the TÜV.

scholarly journals Determining the correlation between daytime and night-time road markings visibility

2016 ◽  
Vol 11 (4) ◽  
pp. 283-290 ◽  
Author(s):  
Dario Babić ◽  
Anđelko Ščukanec ◽  
Darko Babić
Keyword(s):  
Dynamic Test ◽  
Measuring Method ◽  
Objective Evaluation ◽  
Test Method ◽  
Night Time ◽  
Road Section ◽  
Minimum Requirements ◽  
Dynamic Measuring ◽  
The Republic ◽  
The Relationship

Road markings quality control implies conducting several different tests, of which the most significant are visibility tests comprising daytime and night-time visibility measurements by applying the static or the dynamic measuring method. Although the dynamic test method allows measuring the visibility along the entire road section and thus provides a more complete and objective evaluation of road markings quality compared to the static method, it does not measure daytime visibility, for which both the European and the national directives define the minimum requirements. The purpose of this paper is to examine the correlation between daytime and night-time visibility based on static measurements conducted on state roads in the Republic of Croatia. The correlation analysis determined that the strength of relationship between daytime and night-time visibility, is relatively weak. Despite being relatively weak, the relationship still exists, which was the reason for conducting a further analysis. In the analysis, a unique coefficient was obtained through the ratio of retroreflection value and daytime visibility value for all the measurements. The unique coefficient was basis for development of a model that will be able to calculate the daytime visibility based on the results of the dynamic measurements of road markings night-time visibility. The authors evaluated the model with a t-test and concluded that the accuracy of the model is statistically satisfactory.

The importance of aerodynamics for prosthetic limb design used by competitive cyclists with an amputation: An introduction

2014 ◽  
Vol 39 (3) ◽  
pp. 232-237 ◽  
Author(s):  
Bryce Dyer
Keyword(s):  
Field Test ◽  
Aerodynamic Drag ◽  
Field Tests ◽  
Field Testing ◽  
Test Method ◽  
Limb Amputation ◽  
Small Scale ◽  
Prosthetic Limb ◽  
Testing Method ◽  
Competitive Cyclists

Background/Objectives: This study introduces the importance of the aerodynamics to prosthetic limb design for athletes with either a lower-limb or upper-limb amputation. Study design: The study comprises two elements: 1) An initial experiment investigating the stability of outdoor velodrome-based field tests, and 2) An experiment evaluating the application of outdoor velodrome aerodynamic field tests to detect small-scale changes in aerodynamic drag respective of prosthetic limb componentry changes. Methods: An outdoor field-testing method is used to detect small and repeatable changes in the aerodynamic drag of an able-bodied cyclist. These changes were made at levels typical of alterations in prosthetic componentry. The field-based test method of assessment is used at a smaller level of resolution than previously reported. Results: With a carefully applied protocol, the field test method proved to be statistically stable. The results of the field test experiments demonstrate a noticeable change in overall athlete performance. Aerodynamic refinement of artificial limbs is worthwhile for athletes looking to maximise their competitive performance. Conclusion: A field-testing method illustrates the importance of the aerodynamic optimisation of prosthetic limb components. The field-testing protocol undertaken in this study gives an accessible and affordable means of doing so by prosthetists and sports engineers. Clinical relevance Using simple and accessible field-testing methods, this exploratory experiment demonstrates how small changes to riders’ equipment, consummate of the scale of a small change in prosthetics componentry, can affect the performance of an athlete. Prosthetists should consider such opportunities for performance enhancement when possible.

Non-Stoichiometric Compounds Derived From Point Defects

1994 ◽  
Author(s):  
Koji Kosuge
Keyword(s):  
Point Defects ◽  
Stoichiometric Composition ◽  
Pressure Gauge ◽  
Chemical Properties ◽  
Phase Rule ◽  
Chemical Balance ◽  
Long Time ◽  
Oxygen Gas ◽  
Pump Pressure ◽  
The One

In this chapter, we discuss ‘classical’ non-stoichiometry derived from various kinds of point defects. To derive the phase rule, which is indispensable for the understanding of non-stoichiometry, the key points of thermodynamics are reviewed, and then the relationship between the phase rule, Gibbs’ free energy, and non-stoichiometry is discussed. The concentrations of point defects in thermal equilibrium for many types of defect structure are calculated by simple statistical thermodynamics. In Section 1.4 examples of non-stoichiometric compounds are shown referred to published papers. The technical term ‘non-stoichiometric compounds’ has been used for a long time, in contradiction to the term ‘stoichiometric compounds’. The existence of non-stoichiometric compounds, which have also been called Bertholides compounds, cannot be explained from the law of definite proportion in its simplest meaning. Proust insisted that only stoichiometric compounds (also named Daltonide compounds) existed, whereas Bertholet maintained the existence of not only stoichiometric compounds but also non-stoichiometric compounds. This is a very famous argument in the history of chemistry. In the early years of the twentieth century, Kurnakov investigated the physical and chemical properties of intermetallic compounds in detail and found that the maximum or minimum in melting point, electrical resistivity, and also in the ordering temperature of lattices does not necessarily appear at the stoichiometric composition. An important discovery of Dingman was that stoichiometric FeO1.00 is non-existent under ordinary conditions. (At present, we can synthesize stoichiometric FeO1.00 under high pressure.) Non-stoichiometry, which originates from various kinds of lattice defect, can be derived from the phase rule. As an introduction, let us consider a trial experiment to understand non-stoichiometry (this experiment is, in principle, analogous to the one described in Section 1.4.8). Figure 1.1 shows a reaction vessel equipped with a vacuum pump, pressure gauge for oxygen gas, pressure controller for oxygen gas, thermometer, and chemical balance. The temperature of the vessel is controlled by an outer-furnace and the vessel has a special window for in-situ X-ray diffraction. A quantity of metal powder is placed on the chemical balance, and then the vessel is evacuated at room temperature.

A New Dynamic Test Method of Fiber Optic Gyroscope

2012 ◽  
Vol 157-158 ◽  
pp. 245-249 ◽  
Author(s):  
Xu You Li ◽  
Na Zhang
Keyword(s):  
Input Signal ◽  
Fiber Optic ◽  
Dynamic Error ◽  
Dynamic Performance ◽  
Dynamic Test ◽  
Sine Wave ◽  
Test Method ◽  
Working Environment ◽  
Fiber Optic Gyroscope ◽  
Sway Motion

The sway motion of ships follows sine law. Therefore, it needs high dynamic performance of fiber optic gyroscope (FOG) to meet the serious working environment. A new test method was introduced to make reasonable assessment on the dynamic performance of FOG. The principle of this new test method was that the sine wave provided by the IP core in FPGA was superimposed on the digital ladder to simulate the input signal of sway motion. It could be proved that the serial of sine signal, which was generated by this method, was equivalent to the external input signal. Moreover, the dynamic error model of FOG was established to provide the theory of dynamic test. The results of dynamic test of FOG indicated that the dynamic error did not have divergent trends, the system parameters set was reasonable and the FOG system was stable. It also can be seen that dynamic error of FOG was increased with the increasing of sine wave amplitude, which was accord with the actual situation. The new dynamic test method of FOG was verified.

scholarly journals Verification of Optimized Real-time Hybrid Control System for Prediction of Nonlinear Materials Behavior with 3-DOF Dynamic Test

2020 ◽  
Vol 10 (11) ◽  
pp. 4037 ◽  
Author(s):  
Okpin Na ◽  
Jejin Park
Keyword(s):  
Control System ◽  
Real Time ◽  
Shaking Table Test ◽  
Hybrid Control ◽  
Dynamic Test ◽  
Full Scale ◽  
Test Method ◽  
Shaking Table ◽  
Hybrid Test ◽  
Hybrid Control System

Real-time hybrid method is an economical and efficient test method to evaluate the dynamic behavior. The purpose of this study is to develop the computational algorithm and to prove the reliability of a real-time hybrid control system. For performing the multi-direction dynamic test, three dynamic actuators and the optimized real-time hybrid system with new hybrid simulation program (FEAPH) and a simplified inter-communication were optimized. To verify the reliability and applicability of the real-time hybrid control system, 3-DOF (3 Degrees of Freedom) non-linear dynamic tests with physical model were conducted on a steel and concrete frame structure. As a ground acceleration, El Centro and Northridge earthquake waves were applied. As a result, the maximum error of numerical analysis is 13% compared with the result of shaking table test. However, the result of real-time hybrid test shows good agreement with the shaking table test. The real-time hybrid test using FEAPH can make good progress on the total testing time and errors. Therefore, this test method using FEAPH can be effectively and cheaply used to evaluate the dynamic performance of the full-scale structure, instead of shaking table and full-scale test.

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