Modeling and Experimental Study of a Novel Power Split Hydraulic Transmission

2018 ◽  
Author(s):  
Haoxiang Zhang ◽  
Feng Wang ◽  
Bing Xu
Keyword(s):  
Flow Rate ◽  
Experimental Studies ◽  
Friction Torque ◽  
Output Shaft ◽  
Mechanical Power ◽  
Vane Pump ◽  
Input Shaft ◽  
Power Split ◽  
Outlet Flow ◽  
Shaft Torque

The characteristics of a novel power split hydraulic transmission are studied in this paper. The new hydraulic transmission is built from a balanced vane pump with a floating ring. By coupling the floating ring to the output shaft, it becomes a hydraulic transmission, converting the mechanical power on the input shaft into the hydraulic power at the outlet and the mechanical power on the output shaft. By controlling the pressure at the outlet (control pressure), the power ratio transferred through mechanical and hydraulic path can be adjusted. One important feature of the new transmission is that the internal friction torque of the transmission, e.g., friction torque between vane tips and floating ring, helps to drive the output shaft whereas is wasted and turned into heat in a conventional vane pump. This increases the transfer efficiency from input shaft to output shaft. In this study, the characteristics of the input shaft torque, output shaft torque and the outlet flow rate are investigated through experimental studies. Results show that the shaft torques and the outlet flow rate are functions of control pressure and differential shaft speed. The mathematical models have been developed from the analytical and experimental results. The study provides a comprehensive understanding of the new transmission.

A Three-Dimensional CFD Methodology to Study Vane-Ring and Vane-Under-Vane Interactions of a Vane Pump Power Split Transmission

2016 ◽  
Author(s):  
Emma Frosina ◽  
Adolfo Senatore ◽  
Dario Buono ◽  
Kim A. Stelson ◽  
Feng Wang ◽  
...  
Keyword(s):  
Pump Power ◽  
Model Building ◽  
Three Dimensional ◽  
Output Shaft ◽  
University Of Minnesota ◽  
Hydraulic Motor ◽  
Vane Pump ◽  
Input Shaft ◽  
Power Split ◽  
The University

This paper presents a study of a novel vane pump power split transmission (VPPST). The transmission incorporates a new component, the Vane Power Split Unit (VPSU). The VPSU is a double-acting vane pump with a floating ring where the input shaft is connected to the engine and the floating ring is connected to the output shaft. The VPSU generates hydraulic oil flow at a rate proportional to the difference in angular velocities between the input and output shafts. This flow enters a hydraulic motor mounted to the output shaft. The vane pump power split transmission (VPPST) is a combination of the double-acting vane pump (VPSU) and the hydraulic motor directly connected to the pump. A CFD model of the VPSU has been created to better understand its performance. The model uses the three-dimensional CFD commercial code PumpLinx®, developed by Simerics® Inc. Thanks to collaboration with the code developers, the model is able to predict the complex fluid dynamics in the pockets in the rotor into which the vanes retract. These pockets are referred to as under-vane volumes. The rotor of the vane pump, in fact, has several internal channels that connect the pumping chambers between the vanes to the under-vane volumes. The combination of the vanes and the internal ducts and volumes of the under-vanes have been modelled as dynamic “valves” that rotate with the rotor. In this way the radial movements of the vanes are computed as a part of the simulation, based on the pressures due to the compression of the volumes on the inner diameter side of the vanes. The study is a result of collaboration between the University of Minnesota and the University of Naples “Federico II” research groups and the code developers of Simerics® Inc. The universities and Simerics® Inc. have all been involved in this project, working in close cooperation for the model building and simulations.

Design and Analysis of a Large-Scale Positive Displacement Vane Pump for Wind Tower Application

2015 ◽  
Author(s):  
Majid Rashidi ◽  
J. R. Kadambi ◽  
Timothy Hanrahan
Keyword(s):  
Wind Turbines ◽  
Large Scale ◽  
Turbine Blades ◽  
Output Shaft ◽  
Gear Train ◽  
Mechanical Power ◽  
Vane Pump ◽  
Hydraulic Power ◽  
Low Speed ◽  
Overall Efficiency

An innovative combined hydraulic and gear-train power transmissions system for Mega-Watt scale wind turbines is proposed herein. The proposed concept targets large-scale wind turbines for an efficient and reliable conversion of the mechanical power of the rotating blades to electrical power. The novel hybrid system presented in this approach takes advantage of the benefits of both hydraulic and conventional gearbox systems, without introducing their potential inherent undesirable attributes at large scale. The proposed design first converts the mechanical power of the turbine blades to hydraulic power at a relatively high-pressure (about 2,500 psi) under a relatively low-speed (about 4 in/sec). The hydraulic fluid exiting the discharge port of the low-speed hydraulic pump is branched out into plurality of hydraulic lines for the purpose of dividing the total mechanical power of the wind turbine into multitude of lower hydraulic power lines. Each hydraulic line then delivers its hydraulic power into the corresponding intake port of a hydraulic motor having a low-speed-high-torque output shaft. The output shaft of each of the hydraulic motors then drives the input shaft of a mechanically matched gearbox to increase the rotary speed. Finally, the high-speed output shaft of each gearbox (about 1800 RPM) drives a corresponding matched electric generator. A preliminary design for a variable displacement vane pump has been proposed in this paper. This work includes a theoretical analysis of the overall efficiency of the system. The combined volumetric, mechanical, and overall efficiency of a typical proposed system was shown to be about 98%.

Modeling and Influence Study of Gas Bubbles on Characteristics of a Piezoelectric Valve-Less Micropump

2012 ◽  
Author(s):  
Songjing Li ◽  
Jixiao Liu ◽  
Dan Jiang
Keyword(s):  
Flow Rate ◽  
High Speed ◽  
Dynamic Pressure ◽  
Experimental Studies ◽  
Gas Bubbles ◽  
Video Camera ◽  
Pump Chamber ◽  
High Speed Video Camera ◽  
Outlet Flow ◽  
Trapped Gas

The aim of this paper is to develop a theoretical model of a piezoelectric valve-less micropump for liquid delivery with entrapped gas bubbles and evaluate the influence of gas bubbles on the dynamic characteristics of the micropump by using this model. In the model, we consider the vibration of piezoelectric diaphragm, the pressure loss through the nozzle/diffuser and the compressibility of working liquids with entrapped gas bubbles. In order to validate the developed model and make it useful as a design and prediction tool, experimental studies are carried out to investigate the flow rate and dynamic pressure inside the pump chamber when gas bubbles are absent or present in the micropump. The presence of gas bubbles inside the pump chamber is also observed with a high-speed video camera. The outlet flow rate of the micropump with different size of trapped gas bubbles are calculated and compared.

Performance Study of Vane Pump Power Split Transmission for a Highway Vehicle

2015 ◽  
Author(s):  
Biswaranjan Mohanty ◽  
Feng Wang ◽  
Kim A. Stelson
Keyword(s):  
Pump Power ◽  
Continuous Variable ◽  
Control Flow ◽  
Output Shaft ◽  
Performance Study ◽  
Hydraulic Motor ◽  
Vane Pump ◽  
Engine Operation ◽  
Power Split ◽  
Variable Displacement

A novel Vane Pump Power Split Transmission (VPPST), applied to a class 1 pickup truck, is demonstrated in this paper. The VPPST, a power split hydraulic transmission consists of Vane Pump Power Split Unit (VPSU) and a variable displacement hydraulic motor. The VPSU is a double acting vane pump with a floating ring. The floating ring is coupled to the output shaft, which is connected to the drive shaft. The input shaft of the VPSU is coupled to the engine. The control flow of the VPSU is fed to a variable displacement motor mounted on the VPSU output shaft. The transmission ratio is adjusted by controlling the displacement of the variable motor. The resulting continuous variable transmission allows for optimum engine operation by decoupling the engine speed from the drive speed. The transmission also has an integral clutch that allows de-clutching the engine from the drive train by retracting the vanes of the VPSU. In this paper, a quasi-static simulation approach is used to study the performance of the transmission.

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.

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.

Leistungsverzweigter Servopressenantrieb*/Power-split servo press drive - Control of a new servo press drive with mechanical power split

2015 ◽  
Vol 105 (05) ◽  
pp. 291-296
Author(s):  
B.-A. Behrens ◽  
R. Krimm ◽  
J. Jocker ◽  
T. Nitschke
Keyword(s):  
Control Systems ◽  
Operating Costs ◽  
Mechanical Power ◽  
Forming Technology ◽  
Servo Press ◽  
Drive Control ◽  
Power Split ◽  
Control Concept ◽  
High Dynamic ◽  
Special Control

Am Institut für Umformtechnik und Umformmaschinen der Leibniz Universität Hannover wird zurzeit an einer neuartigen Antriebslösung für Servopressen gearbeitet, welche die Vorteile von Servopressen und Exzenterpressen mit Schwungradantrieb vereint. Ziel ist, sowohl bei der Anschaffung als auch im Betrieb Kosten einzusparen. Für die Ansteuerung der Antriebsmotoren wurde ein spezielles Regelkonzept erarbeitet, das sich deutlich von bestehenden Regelungssystemen heutiger Servopressen abgrenzt.   At the Institute of Forming Technology and Machines (Leibniz Universität Hannover), a new drive concept for servo presses is being developed which combines the advantages of servo presses with a high dynamic powertrain and flywheel based eccentric presses. This is intended to save acquisition and operating costs. To control the drive engines, a special control concept has been developed which is completely different from control systems of modern servo presses.

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