Design and experimental studies of a novel double-row radial piston pump

2015 ◽  
Vol 231 (10) ◽  
pp. 1884-1896 ◽  
Author(s):  
Shengdun Zhao ◽  
Tong Guo ◽  
Yanghuiwen Yu ◽  
Peng Dong ◽  
Chen Liu ◽  
...  
Keyword(s):  
Flow Rate ◽  
Rotation Speed ◽  
Experimental Studies ◽  
Piston Pump ◽  
Main Shaft ◽  
Double Row ◽  
Fluctuation Rate ◽  
Improved Design ◽  
Instantaneous Flow Rate ◽  
Wear Condition

This paper proposed a novel double-row radial piston pump. In this pump, the transformation from the rotation of the shaft to the reciprocation of the piston is realized by a pentagon mechanism, and the oil is distributed by check valves, which are integrally designed on the pump body. Theoretical calculation demonstrated that this improved design can substantially reduce the force on the main shaft of pump. The formulas of instantaneous flow rate and fluctuation coefficient of the pump are deduced. For studying the working characteristics of the pump further, a prototype was manufactured and tested. Results show that when the rotation speed is over 125 r/min, the performances of pump prototype are qualified, the fluctuation rate is limited to 20% and the volumetric efficiency can reach 90%. Moreover, the pump was disassembled after 100 h of service and the wear condition was checked. Except for the pentagon which has indentation on the surface, the components of the pump are all kept intact.

Simulation and Analysis on Load-Sensing Swash Plate Piston Pumps Based on AMESim

2014 ◽  
Vol 631-632 ◽  
pp. 723-727 ◽  
Author(s):  
Lan Tang ◽  
Zhuo Qing Li ◽  
Tao Tao Gao
Keyword(s):  
Flow Rate ◽  
Rotation Speed ◽  
Steering System ◽  
Piston Pump ◽  
Load Sensing ◽  
Swash Plate ◽  
Set Up ◽  
Different Parts

Relations between different parts are analyzed based on the structure of load-sensing swash plate piston pump. The models of piston pump and the servomechanism are set up by AMESim and connected with load-sensing steering system. The pressure and flow rate response under different rotation speed without priority valve is researched. The result shows such piston pump model can always response quickly and provide reasonable pressure and flow rate that fit the steering demands.

Modelling and experimental studies on a proportional valve using an innovative dynamic flow-rate measurement in fluid power systems

2017 ◽  
Vol 232 (13) ◽  
pp. 2404-2418 ◽  
Author(s):  
Alessandro Ferrari ◽  
Pietro Pizzo ◽  
Massimo Rundo
Keyword(s):  
Dynamic Response ◽  
Flow Rate ◽  
Experimental Studies ◽  
Fluid Power ◽  
Validation Data ◽  
Proportional Valve ◽  
Instantaneous Flow ◽  
Servo Actuator ◽  
Bode Diagram ◽  
Instantaneous Flow Rate

A numerical model of a servoactuator and of a four-port proportional direction control valve has been developed. Mechanical and hydraulic elements have been simulated in the LMS Amesim® environment. The complete model has been validated on the basis of the experimental time histories of the actuator velocity and of the flow-rate controlled by the proportional valve. The validation data have been acquired on a fluid power system used to test electro-hydraulic servovalves according to ISO 10770-1 standard. The measurement of the instantaneous flow-rate through the valve has been performed with an innovative high-dynamics flowmeter, recently developed for high-pressure liquid flows. Furthermore, the model predicted static characteristic of the proportional valve has been compared with a corresponding experimentally derived curve and an analysis of the cause-and-effect relationships has been carried out for the valve static performance. Measured data on valve leakages have also been presented in order to complete the steady-state characterization of the tested valve. The developed model of the hydraulic system has been then applied to realize the Bode diagram of the proportional valve, which is expressed in terms of instantaneous flow-rate as a function of the sinusoidal driving command, as well as the Bode diagram of the subsystem made up of the proportional valve and of the linear actuator. The latter Bode graph is plotted in terms of piston velocity as a function of the sinusoidal driving command provided to the valve. The comparison between the two Bode diagrams has confirmed the accuracy of the ISO procedure, which is based on the assumption of negligible delay introduced by the dynamic response of the servo-actuator and by the oil compressibility. A reliable and cost-saving methodology, which uses the innovative flowmeter instead of the low inertia servo-actuator, is proposed as an alternative to the ISO standard for testing the dynamic response of proportional valves.

scholarly journals Formation of the Traffic Flow Rate under the Influence of Traffic Flow Concentration in Time at Controlled Intersections in Tyumen, Russian Federation

2021 ◽  
Vol 13 (15) ◽  
pp. 8324
Author(s):  
Viacheslav Morozov ◽  
Sergei Iarkov
Keyword(s):  
Traffic Flow ◽  
Flow Rate ◽  
Traffic Congestion ◽  
Traffic Management ◽  
System Analysis ◽  
Motor Vehicle ◽  
Experimental Studies ◽  
Transport Systems ◽  
Experiment Planning ◽  
Traffic Light

Present experience shows that it is impossible to solve the problem of traffic congestion without intelligent transport systems. Traffic management in many cities uses the data of detectors installed at controlled intersections. Further, to assess the traffic situation, the data on the traffic flow rate and its concentration are compared. Latest scientific studies propose a transition from spatial to temporal concentration. Therefore, the purpose of this work is to establish the regularities of the influence of traffic flow concentration in time on traffic flow rate at controlled city intersections. The methodological basis of this study was a systemic approach. Theoretical and experimental studies were based on the existing provisions of system analysis, traffic flow theory, experiment planning, impulses, probabilities, and mathematical statistics. Experimental data were obtained and processed using modern equipment and software: Traficam video detectors, SPECTR traffic light controller, Traficam Data Tool, SPECTR 2.0, AutoCad 2017, and STATISTICA 10. In the course of this study, the authors analyzed the dynamics of changes in the level of motorization, the structure of the motor vehicle fleet, and the dynamics of changes in the number of controlled intersections. As a result of theoretical studies, a hypothesis was put forward that the investigated process is described by a two-factor quadratic multiplicative model. Experimental studies determined the parameters of the developed model depending on the directions of traffic flow, and confirmed its adequacy according to Fisher’s criterion with a probability of at least 0.9. The results obtained can be used to control traffic flows at controlled city intersections.

Scaling Formulae for the Wellbore Hydraulics Similitude with Drill Pipe Rotation and Eccentricity

2021 ◽  
Author(s):  
Thad Nosar ◽  
Pooya Khodaparast ◽  
Wei Zhang ◽  
Amin Mehrabian
Keyword(s):  
Power Law ◽  
Flow Rate ◽  
Annular Flow ◽  
Rotation Speed ◽  
Drilling Fluid ◽  
Drill Pipe ◽  
Flow Loop ◽  
Annular Flows ◽  
Fluid Rheology ◽  
Pipe Rotation

Abstract Equivalent circulation density of the fluid circulation system in drilling rigs is determined by the frictional pressure losses in the wellbore annulus. Flow loop experiments are commonly used to simulate the annular wellbore hydraulics in the laboratory. However, proper scaling of the experiment design parameters including the drill pipe rotation and eccentricity has been a weak link in the literature. Our study uses the similarity laws and dimensional analysis to obtain a complete set of scaling formulae that would relate the pressure loss gradients of annular flows at the laboratory and wellbore scales while considering the effects of inner pipe rotation and eccentricity. Dimensional analysis is conducted for commonly encountered types of drilling fluid rheology, namely, Newtonian, power-law, and yield power-law. Appropriate dimensionless groups of the involved variables are developed to characterize fluid flow in an eccentric annulus with a rotating inner pipe. Characteristic shear strain rate at the pipe walls is obtained from the characteristic velocity and length scale of the considered annular flow. The relation between lab-scale and wellbore scale variables are obtained by imposing the geometric, kinematic, and dynamic similarities between the laboratory flow loop and wellbore annular flows. The outcomes of the considered scaling scheme is expressed in terms of closed-form formulae that would determine the flow rate and inner pipe rotation speed of the laboratory experiments in terms of the wellbore flow rate and drill pipe rotation speed, as well as other parameters of the problem, in such a way that the resulting Fanning friction factors of the laboratory and wellbore-scale annular flows become identical. Findings suggest that the appropriate value for lab flow rate and pipe rotation speed are linearly related to those of the field condition for all fluid types. The length ratio, density ratio, consistency index ratio, and power index determine the proportionality constant. Attaining complete similarity between the similitude and wellbore-scale annular flow may require the fluid rheology of the lab experiments to be different from the drilling fluid. The expressions of lab flow rate and rotational speed for the yield power-law fluid are identical to those of the power-law fluid case, provided that the yield stress of the lab fluid is constrained to a proper value.

The Study of Fire-extinguishing Process of Modelled Fire Seats

2021 ◽  
pp. 57-62
Author(s):  
V.N. Bordakov ◽  
Keyword(s):  
Flow Rate ◽  
Experimental Studies ◽  
Physical Modelling ◽  
Specific Flow Rate ◽  
Specific Flow ◽  
Acceptable Error ◽  
Fire Extinguishing ◽  
Fire Zone ◽  
Analysis Of Results ◽  
Fire Extinguishers

Test-fires to determine fire-extinguishers’ efficiency for extinguishing B class fires are conducted by operators equipped with working clothes, which does not comply with the requirements of physical modelling. This is why the ranks of extinguished modelled seats are significantly overestimated. The quantitative results of fire seats’ extinguishing can be comparatively evaluated in accordance with the value of specific flow rate of a fire-extinguishing agent. As it was detected, the specific flow rate of a fire-extinguishing agent does not actually depend on the rank of modelled fire seat when extinguished by an operator wearing thermal-protective clothes. At the same time, it is increasing along with the expansion of the fire zone scale in case the fire is extinguished without special protective clothes. Consequently, to increase the fire-extinguisher’s efficiency data reliability, the certifying tests should be conducted in conditions close to the real application conditions when the first person to firefight is not equipped with such special protective clothes. The experimental studies to determine the specific flow rate of a fire-extinguishing agent used modelled fire seats of various ranks. The analysis of results showed that the fire-extinguishers ensuring generation of drops of prevailing size more than 0,5 mm are required to extinguish the modelled sire seats. The degree of increasing flow rate for the fire-extinguishing agent to eliminate a fire and observation of a safe distance from the flame for an operator are conditioned by the scale of fire zone and affect the specific flow rate of agent required to ensure stable fire-extinguishing. Based on the results of extinguishing the fire seats «34В» or «55В», it is demonstrated that via using a correction factor it is possible, assuming an acceptable error, to evaluate the flow rate of fire-extinguishing agent to extinguish a modelled fire seat of any rank.

Effect Of The Rib Inclination Angle On Liquid Film Spreading Over The Structured Surface

2015 ◽  
Vol 10 (1) ◽  
pp. 42-49
Author(s):  
Aleksandr Pavlenko ◽  
Oleg Volodin ◽  
Vladimir Serdyukov
Keyword(s):  
Liquid Film ◽  
Flow Rate ◽  
Inclination Angle ◽  
High Speed ◽  
Film Flow ◽  
Complex Geometry ◽  
Experimental Studies ◽  
Local Flow ◽  
Structured Packing ◽  
Film Spreading

Results of experimental studies on hydrodynamics of the film flow of liquid nitrogen over the surface of the single elements of structured packing are presented. The effect of inclination angle of the large ribs and perforation on the zones of liquid film spreading over the corrugated surface with microtexture at different Reynolds numbers of the film is shown based on a comparison of experimental data. It is shown that the angle of large rib inclination has a significant influence on redistribution of the local flow rate of liquid flowing on the surface with complex geometry. Analysis of results of the high-speed video revealed that in a vicinity of the vertical lateral edges of corrugated plates, the intense rivulet flows are formed, including those with separation from the film flow surface. This negative factor can lead to significant liquid accumulation and flow near the vertical edges of the structured packing and on the inner wall of the heat exchanging apparatuses and, finally, to a significant increase in the degree of maldistribution of local liquid flow rate over the crosssection, for instance, of the distillation columns.

INFLUENCE OF TECHNOLOGICAL FACTORS ON THE EFFICIENCY OF REMOVAL OF SCALE FROM FLATS FOR HOLLOW BALLS

2021 ◽  
pp. 143-147
Author(s):  
А.В. Панфилова ◽  
А.В. Королев ◽  
О.П. Решетникова ◽  
Б.М. Изнаиров ◽  
А.Н. Васин
Keyword(s):  
Rotation Speed ◽  
Experimental Studies ◽  
Surface Cleaning ◽  
Point Of View ◽  
Design Parameters ◽  
Technological Factors ◽  
Proportional Relationship ◽  
Sheet Products ◽  
Process Factors ◽  
Rolled Surface

Рассматриваются результаты проведения экспериментальных исследований способа удаления окалины с поверхности стального листового проката. Предложен новый способ и устройство для очистки поверхности листового проката от окалины режущими пластинами, вращающимися вокруг оси, перемещающейся поступательно вдоль обрабатываемой поверхности. Пластины наклонены в направлении вектора вращения на угол до 10 градусов и упруго поджимаются к обрабатываемой поверхности. Это обеспечивает возможность в процессе очистки поверхности воспроизводить макронеровности листового проката. Приведены результаты экспериментальных исследований, построены математические и графические зависимости, описывающие влияние факторов процесса на эффективность очистки поверхности проката. Показано, что наиболее значимое влияние на параметр оптимизации оказывает сила воздействия инструмента на поверхность заготовки. Причем это влияние реализуется в прямо пропорциональной зависимости. Другие исследованные факторы, а именно: угол наклона пластины, скорость ее вращения и подача, оказывают значительно меньшее влияние на степень очистки проката. Эти исследования были необходимы с точки зрения определения конструктивных параметров силовых элементов как технологической оснастки, реализующей указанный способ, так и технологической установки в целом. План эксперимента был принят, исходя из реальных производственных возможностей индустриального партнера, и соответствовал классическим представлениям теории резания. Описанные результаты дают возможность планировать дальнейшие эксперименты по изучению направлений использования данного способа Here we consider the results of experimental studies of the method of removing scale from the surface of steel sheet products. We propose a new method and device for cleaning the surface of rolled sheets from scale by cutting plates rotating around an axis moving translationally along the treated surface. The plates are tilted in the direction of the rotation vector at an angle of up to 10 degrees and are elastically pressed to the treated surface. This makes it possible to reproduce the macro-dimensions of sheet metal during the surface cleaning process. We present the results of experimental studies. We constructed mathematical and graphical dependences describing the influence of process factors on the efficiency of cleaning the rolled surface. We show that the most significant influence on the optimization parameter is exerted by the force of the tool's impact on the surface of the workpiece. Moreover, this influence is realized in a directly proportional relationship. Other factors studied, namely the angle of inclination of the plate, its rotation speed and feed, have a much smaller impact on the degree of cleaning of rolled products. These studies were necessary from the point of view of determining the design parameters of the power elements of both the technological equipment implementing this method and the technological installation as a whole. We adopted the experimental plan based on the real production capabilities of the industrial partner and corresponded to the classical concepts of the cutting theory. The described results make it possible to plan further experiments to study the directions of using the method

Effect of Blade Aspiration Slot Configuration on the Aerodynamic Performance of a Highly Loaded Aspirated Compressor Cascade

2017 ◽  
Author(s):  
Longxin Zhang ◽  
Le Cai ◽  
Bao Liu ◽  
Jun Ding ◽  
Songtao Wang
Keyword(s):  
Flow Control ◽  
Flow Rate ◽  
Control Method ◽  
Active Flow Control ◽  
Experimental Studies ◽  
Aerodynamic Performance ◽  
Flow Path ◽  
Compressor Cascade ◽  
Flow Loss ◽  
Highly Loaded

As a promising active flow control method, boundary layer suction (BLS) can be used to enhance the aerodynamic performance of the highly-loaded compressor effectively, and due to this reason, extensive studies have been carried out on it. However, contrast to those abundant studies focusing on the flow control effects of BLS, little attention has been paid on the design method of the aspiration flow path. This work presents a 3-D steady numerical simulation on a highly-loaded aspirated compressor cascade. The aspiration slot is implemented at its best location based on the previous experimental studies and the aspiration flow rate is fix to 1.5% of the inlet massflow. The plenum configuration follows the blade shape and remains unchanged. One-side-aspiration manner is adopted to simplify the aspiration devices. Two critical geometry parameters, slot angle and slot width, are varied to study the effects of blade aspiration slot configuration on the cascade loss, radial distribution of the aspiration flow rate and inner flow structures within the aspiration flow path. Results show that the slot configuration does affect the cascade performance. In comparison with the throughflow performance, it is especially true once the flow loss caused by the aspiration flow path is also taken into account, and higher flow loss will be generated within the aspiration flow path if an inappropriate scheme is adopted. In the present investigation, apart from the cases with larger negative slot angle, a wider slot is more preferable to a narrower one, since it could enhance the aspiration capacity near the endwall regions and lower the dissipation loss within the aspiration flow path. In terms of the slot angle, a larger negative value, i.e., the slot direction more aligned with the incoming flow, is not beneficial to improve the throughflow performance, while concerning the flow loss yield by the aspiration flow path, a proper negative slot angle is always optimal.

Fabrication of Rheological Material by Rotating Gas Bubble Stirring

2011 ◽  
Vol 239-242 ◽  
pp. 1573-1576 ◽  
Author(s):  
Lei Zhang ◽  
Xuan Pu Dong ◽  
Wen Jun Wang ◽  
Rong Ma ◽  
Ke Li ◽  
...  
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Rotation Speed ◽  
Gas Bubble ◽  
Gas Flow Rate ◽  
Control Functions ◽  
Stirring Effect ◽  
Strong Convection ◽  
Semi Solid ◽  
Flow Rate Control

A rotating gas bubble stirring technique with specially designed equipment has been developed for the production of light alloy semi-solid slurry. The equipment was specially designed to have temperature, rotation speed and gas flow rate control functions. An Al-Si aluminum alloy was applied as the experimental material. The results showed that large volume of semi-solid slurry could be achieved with the actual stirring temperature of 4 °C to 20 °C below the liquidus temperature of the alloy, and the rotation speed of 195 r/min, and the gas flow rate of 2 L/min. A strong convection and weak stirring effect which was induced by the rotating gas bubbles in the melt was founded responsible for the formation of the semi-solid slurry.

scholarly journals The Effect of Cooling Water Mass Flow Rate Variations on the Heat Pipe Solar Collector Performance

2017 ◽  
Vol 5 (2) ◽  
pp. 31-41
Author(s):  
Abdulsalam D. M. Hassan ◽  
Rwaa Alaa Hussein
Keyword(s):  
Flow Rate ◽  
Solar Collector ◽  
Experimental Studies ◽  
Cooling Water ◽  
Percentage Increase ◽  
Cover Glass ◽  
Language Version ◽  
Theoretical Predictions ◽  
Useful Heat ◽  
Water Mass Flow Rate

The thermal performance of FPHPSC has been studied experimentally and theoretically. The collector consists of copper absorber plate, single glass cover, glass wool insulation and aluminum case. Ten wickless heat pipes of 12.7 mm inner diameter. The experimental studies of collector performance have been performed on four different CWMFR (0.03, 0.04, 0.05 and 0.06) kg/s. The relation between the amount of useful heat, instantaneous collector efficiency and solar intensity is discussed. The collector are tested under the climate condition of Kut city (32.6 latitude and 45.7 longitude). It is investigated that the increasing of CWMFR increase the efficiency of the collector. The percentage increase in the efficiency of the solar collector is in order of (13%), when the cooling water mas flow rate changes from 0.03 kg/sec to 0.06 kg/sec at (45o) collector tilt angle. A computer program based on VISUAL BASIC language (version 6) used for the theoretical analysis. The experimental results are in agreement reasonably with the theoretical predictions.

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