scholarly journals Research on Dynamic Characteristics and Compensation of Wire Rope Tension and Load Measurement Based on Hydraulic Connection Device

2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Di Song ◽  
Gui-Yun Xu ◽  
Gao-Yang Lei ◽  
Xiao-Guang Zhang ◽  
Bao-Lai Tian
Keyword(s):  
Friction Force ◽  
Pressure Loss ◽  
Hydraulic Cylinder ◽  
Wire Rope ◽  
Friction Model ◽  
Inertia Force ◽  
Local Pressure ◽  
Hydraulic Connection ◽  
Load Monitoring ◽  
Flow Pressure

During the operation of hoist, the speed and acceleration of each wire rope are inconsistent and the inertia force is changed due to the wear of the friction pad on the drum, which makes an impact on the cylinder of the tension balance hydraulic connection device and aggravates the flow pressure loss. It results in the nonlinear friction force between the piston and cylinder and affects the accuracy of wire rope tension and load measured by an oil pressure sensor which is installed on the tension balance hydraulic connecting device. In this paper, the simulation model of the tension balanced hydraulic connecting device is established by AMESim software, and the hydraulic dynamic response under different pressures, flow rates, and speed of a single hydraulic cylinder and tension balanced hydraulic connecting device is analyzed. The Leuven friction model is used to compensate the pressure loss along the course and local pressure loss and calculate the friction force, where specific parameters are determined by experiments. The real-time compensation experiment of the tension balance hydraulic connecting device proves that the device effectively improves the accuracy of wire rope tension and load monitoring.

scholarly journals Study on dynamic characteristics and compensation of wire rope tension based on oil pressure sensor

2019 ◽  
Vol 11 (3) ◽  
pp. 168781401983602
Author(s):  
Gaoyang Lei ◽  
Guiyun Xu ◽  
Xiaoguang Zhang ◽  
Baolai Tian
Keyword(s):  
Real Time ◽  
Dynamic Characteristics ◽  
Pressure Loss ◽  
Pressure Sensors ◽  
Hydraulic Cylinder ◽  
Wire Rope ◽  
Friction Model ◽  
Hydraulic Connection ◽  
Operation Process ◽  
Connection System

The oil pressure sensors are installed on the hydraulic connection device to monitor the tension of wire ropes. The change of acceleration during the operation process of hoist causes the tension change of each wire rope. It leads to impact on the cylinder of hydraulic connection device, enlarges the pressure loss, and makes the non-linear friction become more complex which affects the monitoring accuracy. In this article, the mathematical model of hydraulic connection device is established. To analyze the dynamic characteristics of the hydraulic connection system, the model of single hydraulic cylinder and hydraulic connection device is established and simulated by AMESim software. Then, the friction and pressure compensation in the working process of hydraulic connecting device are obtained by LuGre friction model and corresponding formulas of pressure loss. Finally, the monitoring system is designed and real-time compensation test is carried out. The results show that the compensation improves the accuracy of the real-time measurement system of wire rope tension.

scholarly journals Experimental Quantification of Local Pressure Loss at a 90° Bend in Low-Pressure Dilute-Phase Pneumatic Conveying of Coarse Particles

2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Rui Zhu ◽  
Chunsheng Luo ◽  
Xin Li ◽  
Fei Yan
Keyword(s):  
Reynolds Number ◽  
Pressure Loss ◽  
Gas Flow ◽  
Low Pressure ◽  
Pneumatic Conveying ◽  
Local Pressure ◽  
Pressure Loss Coefficient ◽  
Bending Radius ◽  
Flow Pressure ◽  
Gas Ratio

Focusing on the insufficient estimation of the local pressure loss at a 90° horizontal-vertical bend in low-pressure pneumatic conveying of coarse particles, experiments are conducted in a 80 mm inner diameter test bend by using polyethylene particles having an equivalent spherical diameter of 4.00 mm. The influences of the local pressure loss versus the gas flow Reynolds number, the solid-gas ratio, and the bending radius ratio are investigated. Based on the additional pressure theory of Barth, an empirical formula estimating the local pressure loss is obtained using dimensional and nonlinear regression analysis. Summarizing the experiments and literature, the results expound on the local gas flow pressure loss coefficient decreases with increasing Reynolds number, and first decreases and then increases with increasing bending radius ratios from 0.5 to 7. The additional solid flow pressure loss coefficient decreases with the increasing Reynolds number and bending radius ratio in the dilute phase, and linearly increases with increasing solid-gas ratio. Compared with the estimated values with the experimental values, the calculated standard deviation is below 4.11%, indicating that the empirical formula can be used to predict local pressure loss at the bend in the low-pressure dilute-phase pneumatic conveying.

Friction Force and Stresses Analysis for Contact of Assembled Details

2006 ◽  
Vol 113 ◽  
pp. 334-338
Author(s):  
Z. Dreija ◽  
O. Liniņš ◽  
Fr. Sudnieks ◽  
N. Mozga
Keyword(s):  
Mechanical Properties ◽  
Surface Roughness ◽  
Plastic Deformation ◽  
Friction Force ◽  
Sliding Friction ◽  
Friction Model ◽  
Contact Interface ◽  
Finite Element Program ◽  
Elastic Plastic ◽  
Element Program

The present work deals with the computation of surface stresses and deformation in the presence of friction. The evaluation of the elastic-plastic contact is analyzed revealing three distinct stages that range from fully elastic through elastic-plastic to fully plastic contact interface. Several factors of sliding friction model are discussed: surface roughness, mechanical properties and contact load and areas that have strong effect on the friction force. The critical interference that marks the transition from elastic to elastic- plastic and plastic deformation is found out and its connection with plasticity index. A finite element program for determination contact analysis of the assembled details and due to details of deformation that arose a normal and tangencial stress is used.

Relationship Between Unsteady Flow, Pressure Fluctuations, and Noise in a Centrifugal Pump—Part B: Effects of Blade-Tongue Interactions

1995 ◽  
Vol 117 (1) ◽  
pp. 30-35 ◽  
Author(s):  
S. Chu ◽  
R. Dong ◽  
J. Katz
Keyword(s):  
Unsteady Flow ◽  
Centrifugal Pump ◽  
Pressure Difference ◽  
Pressure Fluctuations ◽  
Primary Sources ◽  
Pressure Measurements ◽  
Local Pressure ◽  
Pressure Distributions ◽  
Flow Pressure ◽  
Tip Of The Tongue

Maps of pressure distributions computed using PDV data, combined with noise and local pressure measurements, are used for identifying primary sources of noise in a centrifugal pump. In the vicinity of the impeller pressure minima occur around the blade and near a vortex train generated as a result of non-uniform outflux from the impeller. The pressure everywhere also varies depending on the orientation of the impeller relative to the tongue. Noise peaks are generated when the pressure difference across the tongue is maximum, probably due to tongue oscillations, and when the wake impinges on the tip of the tongue.

scholarly journals Calculation and AFM Experimental Research on Slip Friction for Unlubricated Spherical Contact with Roughness Effect

Micromachines ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1428
Author(s):  
Shengguang Zhu ◽  
Liyong Ni
Keyword(s):  
Friction Force ◽  
Sliding Friction ◽  
Static Friction ◽  
Friction Model ◽  
Rigid Sphere ◽  
Roughness Effect ◽  
Force Microscopy ◽  
Comparison Results ◽  
Experimental Values ◽  
Calculation Models

Previous research on friction calculation models has mainly focused on static friction, whereas sliding friction calculation models are rarely reported. In this paper, a novel sliding friction model for realizing a dry spherical flat contact with a roughness effect at the micro/nano scale is proposed. This model yields the sliding friction by the change in the periodic substrate potential, adopts the basic assumptions of the Greenwood–Williamson random contact model about asperities, and assumes that the contact area between a rigid sphere and a nominal rough flat satisfies the condition of interfacial friction. It subsequently employs a statistical method to determine the total sliding friction force, and finally, the feasibility of this model presented is verified by atomic force microscopy friction experiments. The comparison results show that the deviations of the sliding friction force and coefficient between the theoretical calculated values and the experimental values are in a relatively acceptable range for the samples with a small plasticity index (Ψ ≤ 1).

Simulacija i odstranjivanje stick-slip efekta servosistema sprovodnog aparata hidraulične turbine

2021 ◽  
Vol 23 (1) ◽  
pp. 37-41
Author(s):  
Darko Babunski ◽  
◽  
Emil Zaev ◽  
Atanasko Tuneski ◽  
Laze Trajkovski ◽  
...  
Keyword(s):  
Hydraulic Cylinder ◽  
Friction Model ◽  
Slip Effect ◽  
Hydraulic Systems ◽  
Hydraulic Actuator ◽  
Stick Slip ◽  
Hydro Turbine ◽  
Servo Mechanism ◽  
The Mathematical Model ◽  
Slip Phenomenon

Friction is a repeatable and undesirable problem in hydraulic systems where always has to be a tendency for its removal. In this paper, the friction model is presented through which the most accurate results are achieved and the way of friction compensation, approached trough technique presented with the mathematical model of a hydraulic cylinder of a hydro turbine wicket gate controlled by a servomechanism. Mathematical modelling of a servo mechanism and hydraulic actuator, and also the simulation of hydraulic cylinder as a part of a hydro turbine wicket gate hydraulic system where the stick-slip phenomenon is present between the system components that are in contact is presented. Applied results in this paper and the theory behind them precisely demonstrate under what circumstances the stick-slip phenomenon appears in such a system. The stick-slip effect is simulated using Simulink and Hopsan software and the analysis of the results are given in this paper. Removal of the stick-slip effect is presented with the design of a cascade control implemented to control the behaviour of the system and remove the appearance of a jerking motion.

scholarly journals Validation of Friction Model Parameters Identified Using the IHB Method Using Finite Element Method

2019 ◽  
Vol 2019 ◽  
pp. 1-19
Author(s):  
Abdallah Hadji ◽  
Njuki Mureithi
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Friction Force ◽  
Harmonic Balance ◽  
Harmonic Balance Method ◽  
Friction Model ◽  
Balance Method ◽  
Model Parameters ◽  
Friction Models ◽  
Element Method

A hybrid friction model was recently developed by Azizian and Mureithi (2013) to simulate the friction behavior of tube-support interaction. However, identification and validation of the model parameters remains unresolved. In previous work, the friction model parameters were identified using the reverse harmonic method, where the following quantities were indirectly obtained by measuring the vibration response of a beam: friction force, sliding speed of the force of impact, and local displacement at the contact point. In the present work, the numerical simulation by the finite element method (FEM) of a beam clamped at one end and simply supported with the consideration of friction effect at the other is conducted. This beam is used to validate the inverse harmonic balance method and the parameters of the friction models identified previously. Two static friction models (the Coulomb model and Stribeck model) are tested. The two models produce friction forces of the correct order of magnitude compared to the friction force calculated using the inverse harmonic balance method. However, the models cannot accurately reproduce the beam response; the Stribeck friction model is shown to give the response closest to experiments. The results demonstrate some of the challenges associated with accurate friction model parameter identification using the inverse harmonic balance method. The present work is an intermediate step toward identification of the hybrid friction model parameters and, longer-term, improved analysis of tube-support dynamic behavior under the influence of friction.

The Effects Produced by a Butterfly Valve in a Hydraulic Closed Circuit

2015 ◽  
Vol 811 ◽  
pp. 117-121
Author(s):  
Lucian Mândrea ◽  
Corina Cipu ◽  
Corina Băbuţanu ◽  
Gabriela Oprina
Keyword(s):  
Flow Rate ◽  
Pressure Loss ◽  
Volumetric Flow Rate ◽  
Water Velocity ◽  
Flow Coefficient ◽  
Closed Circuit ◽  
Butterfly Valve ◽  
Local Pressure ◽  
Pressure Transducers ◽  
Average Water

The paper presents the operation of a hydraulic closed circuit equipped with a butterfly valve which can close with a step of 10o. Using four pressure transducers and one temperature transducer, the authors determined the volumetric flow rate, the average water velocity and the local pressure loss in the butterfly valve, the flow coefficient Kv and also the incipient cavitation coefficient. Recommendations for the disposal of the butterfly valve are made and conclusions are obtained regarding the range of opening degrees in which the butterfly valve is better to be used.

Modeling of Hydraulic Line of Device Producing Fluctuant Load Based on Fluid Mechanics

2012 ◽  
Vol 252 ◽  
pp. 56-59
Author(s):  
Xian Bin Wang ◽  
Hong Xing Deng
Keyword(s):  
Fluid Mechanics ◽  
Pressure Loss ◽  
Hydraulic Pressure ◽  
Local Pressure ◽  
Line Model ◽  
Bench Tests ◽  
Friction Pressure ◽  
Experimental Bench ◽  
Pressure Characteristics

The paper deals with modeling of vehicle breaking system hydraulic line based on fluid mechanics. Under the consideration of friction pressure loss and local pressure loss in hydraulic line, an improved hydraulic line model is proposed. The experimental bench tests were carried out based on the device producing fluctuant load to verify the accuracy of the improved hydraulic line model. The system hydraulic pressure characteristics were analyzed by simulation using AMESim software.

CFD Application on Ventilation System of Hydro-Generator

2011 ◽  
Vol 383-390 ◽  
pp. 3561-3565
Author(s):  
Qun Feng Zhang ◽  
Jin Li Yan ◽  
Min Wang ◽  
Zhi Xiang Chen
Keyword(s):  
Pressure Loss ◽  
Rational Design ◽  
Ventilation System ◽  
Local Pressure ◽  
Porous Media Model ◽  
Air Cooler ◽  
Frame Method ◽  
Flow Flux ◽  
Icem Cfd ◽  
Different Parts

Averaged 3D N-S equations and RNG k-ε equations were solved with parallel computing CFD code on the flow field of dual radial ventilation system without fan for a hydro-generator. The MRF(multiple implicit rotating frame) method was used to simulated the rotating motion of the generator and porous media model were used to simulate the pressure loss of air cooler. Rational tactics were selected to generate calculation grids to compromise with calculation CPU time and result accuracy and the grids of different parts were generated with ICEM-CFD. The flow characteristic of different parts was analyzed and flow flux of different section was obtained. The research indicated that the flow from leakage gap between poles and stators formed "air wall", which generated a recirculation zone and made the bar cooling bad. The local pressure loss of stator entrance is dominant. There are leeward and windward areas for the air flowing with circumferential velocity component. Rational design of stator ducts entrance with some diversion effect, can reduce the pressure loss of the stator ventilation and improve the cooling of leeward area in stator ducts.

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