A comparison of harmonic acceleration method with the other commonly used methods for calculation of dynamic transient response

1988 ◽  
Vol 29 (2) ◽  
pp. 227-240 ◽  
Author(s):  
Ž. Lozina
Keyword(s):  
Transient Response ◽  
The Other ◽  
Acceleration Method

Quantitative E-beam Probe for Valid High-Speed Measurements

1999 ◽  
Author(s):  
C. T. Salling
Keyword(s):  
Measurement Error ◽  
Transient Response ◽  
High Speed ◽  
Sampling Time ◽  
The Other ◽  
Other Hand ◽  
Timing Measurement ◽  
Time Accuracy ◽  
Accuracy And Repeatability ◽  
Measurement Capabilities

Abstract This paper presents the results of a study to assess the timing measurement capabilities of e-beam probes and how they compare to mechanical probes in terms of sampling time, accuracy, and repeatability. Analysis of the data indicates that the transient response of mechanical probes is prone to overshoot and ringing, which contributes significantly to measurement error and uncertainty. E-beam probes, on the other hand, are subject to charging effects and interference which, as the authors show, can be effectively eliminated, facilitating high-speed timing measurements accurate to within a few picoseconds.

Forced and Free Motion of a Mass on an Air Spring

1944 ◽  
Vol 11 (2) ◽  
pp. A101-A107
Author(s):  
B. Sussholz
Keyword(s):  
Mechanical System ◽  
Nonlinear Elasticity ◽  
Theoretical Investigation ◽  
Transient Response ◽  
Cylindrical Tube ◽  
The Other ◽  
Air Spring ◽  
Nonlinear Mechanical ◽  
Nonlinear Mechanical System ◽  
Applied Forces

Abstract Results are given of a theoretical investigation of the transient response of a simple nonlinear mechanical system to various types of applied forces. A cylindrical tube closed at one end, with a light piston inserted in the other, was used experimentally, the nonlinear elasticity of the confined column of air governing the motion of the piston. Such systems have been used in ballistic studies to measure transient pressures, as well as for the measurement of pressures caused by other types of explosions in air.

Switching-Type Self-Tuning Fuzzy PID Control of an Active Magnetic Bearing System

2013 ◽  
Vol 284-287 ◽  
pp. 2330-2336
Author(s):  
Kuan Yu Chen ◽  
Pi Cheng Tung ◽  
Yi Hua Fan
Keyword(s):  
Steady State ◽  
Transient Response ◽  
Pid Control ◽  
Magnetic Bearing ◽  
Active Magnetic Bearing ◽  
The Other ◽  
Fuzzy Pid ◽  
Switching Type ◽  
Self Tuning ◽  
Amb System

This paper presents a new switching control scheme for an active magnetic bearing (AMB) system using self-tuning fuzzy proportional-integral-derivative (PID) control. The research process consists of three stages. First, four types of self-tuning fuzzy PID-type controllers (FPIDCs) consisting of two most commonly used fuzzy inference systems: Mamdani and Takagi-Sugeno types, and two efficient parameter adaptive methods: function tuner and relative rate observer, are used to control a highly nonlinear AMB system, respectively. Hence, there are two kinds of FPIDCs can be obtained by comparing experimental results of these tests: one has the fastest transient response and the other has the minimum steady-state error. Next, the switching-type self-tuning FPIDC is proposed by combining the two kinds of FPIDCs. Namely, the AMB system is dominated by the scheme with the fastest transient response when the rotor is at rest and by the one with the best steady-state performance when the rotor is in rotation. Finally, experimental results demonstrate that the proposed switching-type self-tuning FPIDC performs better overall performance than the other self-tuning FPIDCs, particularly when controlling an AMB system.

scholarly journals Experiment and Analysis on the Free Dynamics of a Shallow Arch After an Impact Load at the End

2005 ◽  
Vol 72 (1) ◽  
pp. 54-61 ◽  
Author(s):  
Jen-San Chen ◽  
Chun-Yi Liao
Keyword(s):  
Transient Response ◽  
Impact Load ◽  
Minimum Energy ◽  
The Other ◽  
Initial Speed ◽  
Attached Mass ◽  
Shallow Arch ◽  
Theoretical Predictions ◽  
The Impact ◽  
Good Agreement

In this paper we consider a sinusoidal arch with one end pinned in space while the other end attached to a mass and supported by a spring. The supporting wall of the spring is moved a distance quasi-statically to initiate preload in the arch and the spring. The assembly is then set in motion by an impact at the attached mass. The condition under which the arch may snap to the other side dynamically depends on the initial speed of the attached mass due to impact. Sufficient condition on the initial speed against dynamic snap-through is formulated based on the concept of minimum energy barrier. The effects of damping on the transient response of the assembly are also discussed. An experimental setup is designed to measure the transient response of the arch following the impact and the critical initial speed of the attached mass. The experimental results are in good agreement with theoretical predictions.

Experimental Characterization of the Transient Response of Air/Water Crossflow Heat Exchangers for Data Center Cooling Systems

2015 ◽  
Author(s):  
Marcelo del Valle ◽  
Alfonso Ortega
Keyword(s):  
Heat Exchanger ◽  
Water Flow ◽  
Transient Response ◽  
Data Center ◽  
Heat Exchangers ◽  
The Other ◽  
Experimental Characterization ◽  
Cooling Systems ◽  
Hybrid Cooling

Data Center hybrid air/liquid cooling systems such as rear door heat exchangers, overhead and in row cooling systems enable localized, on-demand cooling, or “smart cooling.” At the heart of all hybrid cooling systems is an air to liquid cross flow heat exchanger that regulates the amount of cooling delivered by the system by modulating the liquid or air flows and/or temperatures. Due the central role that the heat exchanger plays in the system response, understanding the transient response of the heat exchanger is crucial for the precise control of hybrid cooling system. This paper reports on the transient experimental characterization of heat exchangers used in data centers applications. An experimental rig designed to introduce controlled transient perturbations in temperature and flow on the inlet air and liquid flow streams of a 12 in. × 12 in. heat exchanger test core is discussed. The conditioned air is delivered to the test core by a suction wind tunnel with upstream air heaters and a frequency variable axial blower to allow the control of air flow rate and bulk temperature. The conditioned water is delivered to the test core by a water delivery system consisting of two separate water circuits, one delivering cold water, and the other hot water. By switching from one circuit to the other or mixing water from both circuits, the rig is capable of generating step, ramp and frequency perturbations in water temperature at constant flow or step, ramp or frequency perturbations in water flow at constant temperature or combinations of temperature and water flow perturbations. Experimental data are presented for a 12×12 heat exchanger core with a single liquid pass under different transient perturbations.

Thin Film Conducting and Semiconducting Resistance Thermometers for Surface Temperature Measurement

1977 ◽  
Vol 99 (3) ◽  
pp. 385-390 ◽  
Author(s):  
R. J. Hannemann
Keyword(s):  
Thin Film ◽  
Heat Transfer ◽  
Transient Response ◽  
Accurate Determination ◽  
The Other ◽  
Experimental Task ◽  
Surface Temperature Measurement ◽  
Resistance Thermometers ◽  
High Conductance

The accurate determination of surface temperatures, especially during high conductance processes such as condensation or boiling, without affecting the heat transfer phenomena under study, is a challenging experimental task. The present work describes the fabrication and characteristics of two unique types of surface thermometers produced using microelectronic thin film technology. One uses titanium in a meandering pattern to measure surface average temperatures, while the other, using germanium, was designed for point measurements and rapid transient response. An application to experiments involving dropwise condensation of steam is considered in detail.

Stromatoporoids from the Famennian (Devonian) Wabamun Formation, Normandville oilfield, north–central Alberta, Canada

1988 ◽  
Vol 62 (03) ◽  
pp. 411-419 ◽  
Author(s):  
Colin W. Stearn
Keyword(s):  
Patch Reef ◽  
Abundant Species ◽  
The Other ◽  
North Central ◽  
Biotic Crisis

Stromatoporoids are the principal framebuilding organisms in the patch reef that is part of the reservoir of the Normandville field. The reef is 10 m thick and 1.5 km2in area and demonstrates that stromatoporoids retained their ability to build reefal edifices into Famennian time despite the biotic crisis at the close of Frasnian time. The fauna is dominated by labechiids but includes three non-labechiid species. The most abundant species isStylostroma sinense(Dong) butLabechia palliseriStearn is also common. Both these species are highly variable and are described in terms of multiple phases that occur in a single skeleton. The other species described areClathrostromacf.C. jukkenseYavorsky,Gerronostromasp. (a columnar species), andStromatoporasp. The fauna belongs in Famennian/Strunian assemblage 2 as defined by Stearn et al. (1988).

D. The Line Spectrum of Pulsating Variable Stars

1967 ◽  
Vol 28 ◽  
pp. 207-244
Author(s):  
R. P. Kraft
Keyword(s):  
Variable Stars ◽  
The Other ◽  
Line Spectrum ◽  
Afternoon Session ◽  
Empirical Information ◽  
Pulsating Variable Stars ◽  
Almost Continuous ◽  
Informal Approach

(Ed. note:Encouraged by the success of the more informal approach in Christy's presentation, we tried an even more extreme experiment in this session, I-D. In essence, Kraft held the floor continuously all morning, and for the hour and a half afternoon session, serving as a combined Summary-Introductory speaker and a marathon-moderator of a running discussion on the line spectrum of cepheids. There was almost continuous interruption of his presentation; and most points raised from the floor were followed through in detail, no matter how digressive to the main presentation. This approach turned out to be much too extreme. It is wearing on the speaker, and the other members of the symposium feel more like an audience and less like participants in a dissective discussion. Because Kraft presented a compendious collection of empirical information, and, based on it, an exceedingly novel series of suggestions on the cepheid problem, these defects were probably aggravated by the first and alleviated by the second. I am much indebted to Kraft for working with me on a preliminary editing, to try to delete the side-excursions and to retain coherence about the main points. As usual, however, all responsibility for defects in final editing is wholly my own.)

C. The Continuous Spectrum of Pulsating Variable Stars

1967 ◽  
Vol 28 ◽  
pp. 177-206
Author(s):  
J. B. Oke ◽  
C. A. Whitney
Keyword(s):  
Continuous Spectrum ◽  
Variable Stars ◽  
Velocity Fields ◽  
The Other ◽  
Line Spectrum ◽  
Direct Information ◽  
Thermodynamic Structure ◽  
Diagnostic Interpretation ◽  
Pulsating Variable Stars ◽  
The Continuum

Pecker:The topic to be considered today is the continuous spectrum of certain stars, whose variability we attribute to a pulsation of some part of their structure. Obviously, this continuous spectrum provides a test of the pulsation theory to the extent that the continuum is completely and accurately observed and that we can analyse it to infer the structure of the star producing it. The continuum is one of the two possible spectral observations; the other is the line spectrum. It is obvious that from studies of the continuum alone, we obtain no direct information on the velocity fields in the star. We obtain information only on the thermodynamic structure of the photospheric layers of these stars–the photospheric layers being defined as those from which the observed continuum directly arises. So the problems arising in a study of the continuum are of two general kinds: completeness of observation, and adequacy of diagnostic interpretation. I will make a few comments on these, then turn the meeting over to Oke and Whitney.

Observing programme for the 24-inch/36-inch Schmidt telescope

1966 ◽  
Vol 24 ◽  
pp. 337
Author(s):  
W. Iwanowska
Keyword(s):  
The Other ◽  
Schmidt Telescope ◽  
Flint Glass

A new 24-inch/36-inch//3 Schmidt telescope, made by C. Zeiss, Jena, has been installed since 30 August 1962, at the N. Copernicus University Observatory in Toruń. It is equipped with two objective prisms, used separately, one of crown the other of flint glass, each of 5° refracting angle, giving dispersions of 560Å/mm and 250Å/ mm respectively.

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