An Analytical and Experimental Study of the Dynamic Behavior of a Quick-Acting Hydraulic Fuse

The dynamic behavior of a quick-acting hydraulic fuse is investigated here by analysis and experiment. The fuse has a very short response time and is designed to respond to pressure and flow transients that immediately follow a line rupture. In view of the short response time, a proper dynamic analysis of the entire hydraulic circuit is necessary, in addition to analysis of the fuse behavior. Dynamic models of the fuse and other hydraulic circuit elements used in the experimental setup are presented. The experiments consist of simulating line leaks and measuring fuse response, under a variety of operating conditions. Experimental and analytical results are in very good agreement if the leak transients are properly characterized.

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Dynamic analysis of a helical gear reduction by experimental and numerical methods

Noise Control Engineering Journal ◽

10.3397/1/37684 ◽

2020 ◽

Vol 68 (1) ◽

pp. 48-58

Author(s):

Chao Liu ◽

Zongde Fang ◽

Fang Guo ◽

Long Xiang ◽

Yabin Guan ◽

...

Keyword(s):

Numerical Methods ◽

Dynamic Analysis ◽

Dynamic Behavior ◽

Fourth Order ◽

Numerical Models ◽

Helical Gear ◽

Operating Conditions ◽

Dynamic Responses ◽

Lumped Mass ◽

Gear Mesh

Presented in this study is investigation of dynamic behavior of a helical gear reduction by experimental and numerical methods. A closed-loop test rig is designed to measure vibrations of the example system, and the basic principle as well as relevant signal processing method is introduced. A hybrid user-defined element model is established to predict relative vibration acceleration at the gear mesh in a direction normal to contact surfaces. The other two numerical models are also constructed by lumped mass method and contact FEM to compare with the previous model in terms of dynamic responses of the system. First, the experiment data demonstrate that the loaded transmission error calculated by LTCA method is generally acceptable and that the assumption ignoring the tooth backlash is valid under the conditions of large loads. Second, under the common operating conditions, the system vibrations obtained by the experimental and numerical methods primarily occur at the first fourth-order meshing frequencies and that the maximum vibration amplitude, for each method, appears on the fourth-order meshing frequency. Moreover, root-mean-square (RMS) value of the acceleration increases with the increasing loads. Finally, according to the comparison of the simulation results, the variation tendencies of the RMS value along with input rotational speed agree well and that the frequencies where the resonances occur keep coincident generally. With summaries of merit and demerit, application of each numerical method is suggested for dynamic analysis of cylindrical gear system, which aids designers for desirable dynamic behavior of the system and better solutions to engineering problems.

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Nonlinear Dynamic Analysis of a Flexible Rotor Supported by Externally Pressurized Porous Gas Journal Bearings

Journal of Tribology ◽

10.1115/1.1467637 ◽

2002 ◽

Vol 124 (3) ◽

pp. 553-561 ◽

Cited By ~ 16

Author(s):

Cheng-Chi Wang ◽

Cheng-Ying Lo ◽

Cha’o-Kuang Chen

Keyword(s):

Dynamic Analysis ◽

Dynamic Behavior ◽

Nonlinear Dynamic ◽

Nonlinear Dynamic Analysis ◽

Power Spectra ◽

Journal Bearings ◽

Operating Conditions ◽

Flexible Rotor ◽

Bearing Number ◽

Rotor Mass

This paper studies the nonlinear dynamic analysis of a flexible rotor supported by externally pressurized porous gas journal bearings. A time-dependent mathematical model for externally pressurized porous gas journal bearings is presented. The finite difference method and the Successive Over Relation (S.O.R.) method are employed to solve the modified Reynolds’ equation. The system state trajectory, Poincare´ maps, power spectra, and bifurcation diagrams are used to analyze the dynamic behavior of the rotor and journal center in the horizontal and vertical directions under different operating conditions. The analysis reveals a complex dynamic behavior comprising periodic and quasi-periodic response of the rotor and journal center. This paper shows how the dynamic behavior of this type of system varies with changes in rotor mass and bearing number. The results of this study contribute to a further understanding of the nonlinear dynamics of gas-lubricated, externally pressurized, porous rotor-bearing systems.

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Experimental Setup for Dynamic Analysis of Micro- and Nano-Mechanical Systems in Vacuum, Gas, and Liquid

Micromachines ◽

10.3390/mi10030162 ◽

2019 ◽

Vol 10 (3) ◽

pp. 162 ◽

Cited By ~ 1

Author(s):

Bram van den Brink ◽

Farbod Alijani ◽

Murali Ghatkesar

Keyword(s):

Dynamic Analysis ◽

Element Model ◽

Dynamic Responses ◽

Experimental Setup ◽

Force Microscopy ◽

Frequency Responses ◽

Atomic Force ◽

Different Types ◽

Langevin Transducer ◽

Good Agreement

An experimental setup to perform dynamic analysis of a micro- and nano-mechanical system in vacuum, gas, and liquid is presented. The setup mainly consists of a piezoelectric excitation part and the chamber that can be either evacuated for vacuum, or filled with gas or water. The design of the piezoelectric actuator was based on a Langevin transducer. The chamber is made out of materials that can sustain: vacuum, variety of gases and different types of liquids (mild acids, alkalies, common alcohols and oils). All the experiments were performed on commercial cantilevers used for contact and tapping mode Atomic Force Microscopy (AFM) with stiffness 0.2 N/m and 48 N/m, respectively, in vacuum, air and water. The performance of the setup was evaluated by comparing the measured actuator response to a finite element model. The frequency responses of the two AFM cantilevers measured were compared to analytical equations. A vacuum level of 0.6 mbar was obtained. The setup has a bandwidth of 10–550 kHz in vacuum and air, and a bandwidth of 50–550 kHz in liquid. The dynamic responses of the cantilevers show good agreement with theory in all media.

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Experimental Leak-Rate Measurement Through a Static Metal Seal

Journal of Fluids Engineering ◽

10.1115/1.2734250 ◽

2006 ◽

Vol 129 (6) ◽

pp. 799-805 ◽

Cited By ~ 30

Author(s):

Christophe Marie ◽

Didier Lasseux

Keyword(s):

Experimental Study ◽

Operating Conditions ◽

Leak Rate ◽

Metal Contact ◽

Experimental Setup ◽

Rate Measurement ◽

Species Concentration ◽

Great Precision ◽

Effective Contact ◽

Metal Seal

This paper presents an experimental study to characterize fluid leakage through a rough metal contact. The focus is on an original experimental setup and procedure designed to measure the fluid micro (or nano) leak rate with great precision over several orders of magnitude. Liquid leak-rate measurements were carried out under two distinct operating conditions, i.e., in the case of a pressure gradient applied between contact edges and in the case of a pure diffusive effect resulting from a species concentration gradient. Experimental leak-rate results are discussed in terms of effective contact permeability—or transmissivity—and in terms of effective contact diffusivity versus contact tightening.

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Nonlinear Vibrations of an Inclined Cable

Volume 5: 19th Biennial Conference on Mechanical Vibration and Noise, Parts A, B, and C ◽

10.1115/detc2003/vib-48616 ◽

2003 ◽

Author(s):

A. Berlioz ◽

C.-H. Lamarque

Keyword(s):

Experimental Study ◽

Nonlinear Vibrations ◽

Dynamic Models ◽

Theoretical Study ◽

Second Harmonic ◽

Copper Wire ◽

Steel Wire ◽

Type Construction ◽

Inclined Cable ◽

Good Agreement

An experimental and theoretical study is carried out with the aim of using existing breadboard type construction in order to validate dynamic models. This experimental study highlights the nonlinear dynamic behavior of a cable consisting of a steel wire surrounded by copper wire. New measurements around the first frequency of vibration of the cable in and out of the plane and around the second harmonic of this frequency were also carried out. These results are in good agreement with the results obtained analytically via new finite (1,2,4) degree-of-freedom models.

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Dynamic Analysis of a Flapper-Nozzle Valve

Journal of Dynamic Systems Measurement and Control ◽

10.1115/1.2896343 ◽

1991 ◽

Vol 113 (1) ◽

pp. 163-167 ◽

Cited By ~ 23

Author(s):

S. J. Lin ◽

A. Akers

Keyword(s):

Dynamic Analysis ◽

Dynamic Behavior ◽

Nonlinear Theory ◽

Previous Analysis ◽

Experimental Results ◽

Piston Flow ◽

Good Agreement

A previous analysis into the dynamic behavior of the flapper-nozzle component of the electrohydraulic servovalve was performed after linearization of the equations relating to control piston flow (Lin and Akers, 1989a). This paper reports results for first-stage gain and for dynamic behavior when linearization has not been performed. Good agreement has been achieved between results calculated from the nonlinear theory presented and experimental results.

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On the Dynamic Analysis of Roller Chain Drives: Part I — Theory

22nd Biennial Mechanisms Conference: Mechanism Design and Synthesis ◽

10.1115/detc1992-0326 ◽

1992 ◽

Author(s):

Nicholas M. Veikos ◽

Ferdinand Freudenstein

Keyword(s):

Dynamic Analysis ◽

Dynamic Behavior ◽

Span Length ◽

Additional Insight ◽

Roller Chain ◽

Computer Aided ◽

Chain Dynamic ◽

Chain Drives ◽

Insight Into ◽

Good Agreement

Abstract A generally applicable, computer-aided procedure has been developed for the dynamic analysis of roller chain drives. This approach addresses important factors of chain dynamic behavior such as impact, discontinuities in span length, chain elasticity, coupling between longitudinal and transverse motions, as well as coupling between motion and boundary conditions. The procedure has been used to study various chain configurations. The results show good agreement with experimental observations and indicate some general trends, which provide additional insight into the dynamic behavior of these systems.

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Experimental COP evaluation of a 65-litre household refrigerator running with R600a

E3S Web of Conferences ◽

10.1051/e3sconf/202128601008 ◽

2021 ◽

Vol 286 ◽

pp. 01008

Author(s):

Saleh J. Alqaisy ◽

Kamel S. Hmood ◽

Mahdi Hatf Kadhum Aboaltabooq ◽

Valentin Apostol ◽

Horatiu Pop ◽

...

Keyword(s):

Experimental Data ◽

Cooling Capacity ◽

Operating Conditions ◽

Experimental Setup ◽

Data Sets ◽

Quasi Steady State ◽

Maximum Value ◽

Main Components ◽

Compressor Power ◽

Good Agreement

A household refrigerator is a major energy consumer in all homes. The paper aims to evaluate based, on experimental data, the COP of a 65-liter household refrigerator operating with R600a. The main components and instrumentation of the experimental setup are presented. A mathematical model based on the energy balance of the refrigerated enclosure is developed in order to evaluate the COP. Three experimental data sets have been obtained in quasi-steady-state operating conditions. The results point out that the compressor power absorbed from the grid was 60 [W]. The maximum value for the cooling capacity is 81.73 W while the minimum value is 80.24 W. In terms of COP, the maximum value obtained is 1.362, while the minimum one is 1.337. The COP values obtained in the present study are in good agreement with the ones displayed by the manufacturer in the compressor datasheet. Future development is discussed.

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