Static and Dynamic Experimental Investigation of a Pneumatic Open Loop Proportional Valve

2016 ◽  
Vol 40 (5) ◽  
pp. 1377-1385 ◽  
Author(s):  
L. Gastaldi ◽  
S. Pastorelli ◽  
M. Sorli
Keyword(s):  
Experimental Investigation ◽  
Open Loop ◽  
Proportional Valve

An Experimental Investigation of the Dynamics of a Loosely Supported Tube Array

2017 ◽  
Author(s):  
Amro Elhelaly ◽  
Marwan Hassan ◽  
Atef Mohany ◽  
Soha Moussa
Keyword(s):  
Experimental Investigation ◽  
Impact Force ◽  
Cross Flow ◽  
Open Loop ◽  
Diameter Ratio ◽  
Force Level ◽  
Steam Generators ◽  
Flow Induced Vibration ◽  
System Integrity ◽  
Tube Bundles

The integrity of tube bundles is very important especially when dealing with high-risk applications such as nuclear steam generators. A major issue to system integrity is the flow-induced vibration (FIV). FIV is manifested through several mechanisms including the most severe mechanism; fluidelastic instability (FEI). Tube vibration can be constrained by using tube supports. However, clearances between the tube and their support are required to allow for thermal expansion and for other manufacturing considerations. The clearance between tubes may allow frequent impact and friction between tube and support. This in turn may cause fatigue and wear at support and potential for catastrophic tube failure. This study aims to investigate the dynamics of loosely supported tube array subjected to cross-flow. The work is performed experimentally in an open-loop wind tunnel to address this issue. A loosely-supported single flexible tube in both triangle and square arrays subjected to cross-flow with a pitch-to-diameter ratio of 1.5 and 1.733, respectively were considered. The effect of the flow approach angle, as well as the support clearance on the tube response, are investigated. In addition, the parameters that affect tube wear such as impact force level are presented.

Modeling of a Hydraulic Elevator Driven by an Open-Loop Control

2009 ◽  
Author(s):  
Roberto Strada ◽  
Alberto Oldani
Keyword(s):  
Power Generation ◽  
Closed Loop ◽  
Open Loop ◽  
The Other ◽  
Open Loop Control ◽  
Proportional Valve ◽  
Loop Control ◽  
Complete Knowledge ◽  
Motion Time ◽  
Loop Control System

Electro-hydraulic elevators are widely used systems, especially in low level buildings, due to their very good ratio between power generation and dynamic response. Generally, the goal of an elevator system is just to reach the floor with a precision enough to be comfortable for the passengers, without the need to follow a specific law of motion; hence an open-loop control system could be enough. Otherwise such a kind of solution reduces the number of components, bringing down the costs of production. On the other hand a complete knowledge of the mechanical system’s behaviour is required. In this work we deal with the analysis of the behaviour of a commercial hydraulic elevator driven by an open loop control that monitors the downstream pressure of the proportional valve supplying the cylinder. At the end of the paper, a closed loop solution based on the pressure measurement and on the motion time is proposed.

scholarly journals Theoretical and experimental investigation on novel 2D maglev servo proportional valve

2021 ◽  
Vol 34 (4) ◽  
pp. 416-431
Author(s):  
Bin MENG ◽  
Hao XU ◽  
Jian RUAN ◽  
Sheng LI
Keyword(s):  
Experimental Investigation ◽  
Proportional Valve

An Experimental Investigation of Dynamic Factors in Spur and Helical Gears

1970 ◽  
Vol 92 (2) ◽  
pp. 495-503 ◽  
Author(s):  
D. R. Houser ◽  
A. Seireg
Keyword(s):  
Experimental Investigation ◽  
Dynamic Load ◽  
Open Loop ◽  
Operating Conditions ◽  
Mesh Stiffness ◽  
Test Program ◽  
Helical Gears ◽  
Dynamic Factors ◽  
Comprehensive Test

This paper describes a comprehensive test program for the investigation of the influence of errors and variations in mesh stiffness on the peak stresses developed in spur and helical gears. The study is primarily concerned with speed effects on tooth loads in regions away from resonance. Four sets of specially designed and instrumented gears were tested in an open-loop setup. The interaction between tooth loads and system shaft torques at different operating conditions is also investigated. The results are utilized in the accompanying paper for the development of a generalized dynamic load formula for spur and helical gears.

scholarly journals Experimental Investigation on Heat Transfer Characteristics of an Open Loop Pulsating Heat Pipe(OLPHP) with Fin

2015 ◽  
Vol 105 ◽  
pp. 113-120 ◽  
Author(s):  
Md Lutfor Rahman ◽  
Pijush Kanti Saha ◽  
Fariha Mir ◽  
Asfia Tanjim Totini ◽  
Sumaiya Nawrin ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Experimental Investigation ◽  
Heat Pipe ◽  
Open Loop ◽  
Pulsating Heat Pipe ◽  
Heat Transfer Characteristics ◽  
Transfer Characteristics

Dynamic analysis of an open-loop proportional valve controlled hydrostatic drive

2019 ◽  
Vol 233 (6) ◽  
pp. 1245-1256 ◽  
Author(s):  
K Dasgupta ◽  
Sanjoy K Ghoshal ◽  
Sujit Kumar ◽  
J Das
Keyword(s):  
Dynamic Analysis ◽  
Flow Characteristics ◽  
Open Loop ◽  
Critical Parameters ◽  
Test Results ◽  
Proportional Valve ◽  
Detailed Model ◽  
Proposed Model ◽  
Graph Simulation ◽  
Drive Model

This article highlights the dynamic analysis of a proportional valve controlled hydrostatic drive. Such drives are used widely in construction and mining applications. In the drive considered for the analysis, the speed of a bent-axis hydro-motor is controlled by varying flow supplied through a proportional direction controlled valve. A non-linear mathematical model using bond graph simulation technique is developed, where detailed model of the drive system including its loading arrangement is incorporated. From the test results of the pressure-flow characteristics of the valves, its port resistances are identified. Using them and taking into account various losses of the hydro-motor, the drive model is validated through experiments. The verified model is used to study the effects of the perturbations of some critical parameters on the transient responses of the hydrostatic drive through simulation. The proposed model may be useful for initial design of such drive and the development of control systems where these drives are used as actuators.

Set of open-loop block-diagonalizers of transfer matrices

1989 ◽  
Vol 49 (1) ◽  
pp. 161-168
Author(s):  
A. Bülent Özgü Ler ◽  
Vasfi Eldem
Keyword(s):  
Open Loop ◽  
Transfer Matrices
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