Results 251 to 260 of about 109,007 (299)

Impedance Measurements of Inertance Tubes for Pulse Tube Cryocoolers

Advanced Materials Research, 2013
The impedance of the inertance tubes which include the mass flows, pressure amplitudes and phase shifts between them at the inlet of the inertance tubes were measured by correcting the mass flows at the surface of the compressor piston. The experimental results are compared with the theoretical values based on simplified turbulent-flow thermoacoustic ...
S.S. Li, Y.N. Wu
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Impedance Measurements of Inertance Tubes

AIP Conference Proceedings, 2006
The flow impedance of an inertance tube of 5.74 mm inside diameter and 2.36 m long coupled to various reservoir volumes was measured and compared with that predicted by a model based on a transmission line analogy. Though data at other average pressures and temperatures were obtained, this paper focuses on data taken with an average pressure of 2.5 MPa
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Coupling Impedance of Cylindrical Tubes

IEEE Transactions on Electromagnetic Compatibility, 1972
The concept of a coupling (transfer) impedance as developed by Schelkunoff for cylindrical tubes is applied in the determination of the mutual coupling to a grounded coaxial cable. Formulas are developed utilizing the coupling impedance concept when the exciting, or interfering, circuit is either a single-wire line or another coaxial cable over a ...
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Traveling-Wave Tube Helix Impedance

Proceedings of the IRE, 1953
The impedance parameter of a circular helix, from which the gain of a helix-type traveling wave amplifier is computed, is investigated for a "Tape-Helix" model. Results obtained in this paper indicate that the impedance has a smaller value than for the "Sheath-Helix" model, and is considerably reduced at larger values of ka, the ratio of the helix ...
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Development of an Indigenous Impedance Tube

Applied Mechanics and Materials, 2015
Fabrication of an impedance tube for measuring sound absorption coefficient is presented in this paper. Transfer-function method is chosen for the sound absorption analysis. The impedance tube is designed and fabricated in accordance with ISO 10534-2. The tube is made from brass with diameter of 114.3 mm and length of 1.42 m.
Wei Hong Tan, Rosmaini Ahmad, Nur Hafizah Zunaidi, Ruslizam Daud, E.M. Cheng   +4 more
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Comments on impedance tube measurements

The Journal of the Acoustical Society of America, 1981
The application of a new impedance measuring method to water-filled tubes is discussed. It is shown that source reflections do not invalidate the method, and that valid results can be obtained at frequencies several times higher than that of the first cross mode of the tube.
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Transverse Impedance of Two-Layer Tube

Proceedings of the 2005 Particle Accelerator Conference, 2006
The exact analytical expressions for the multipole longitudinal and transverse impedances of two-layer tube with finite wall thickness are obtained. The numerical examples for the impedances of the vacuum chamber with laminated walls are given.
M. Ivanyan, A.V. Tsakanian
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Automation of impedance tube measurements

The Journal of the Acoustical Society of America, 1975
An apparatus is described that enables the automatic determination of impedance tube data, namely, the positions of the first two minima and the standing-wave ratios along the tube. Subject Classification: 85.20.
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A two-microphone thermoacoustic impedance tube

The Journal of the Acoustical Society of America, 2000
An experimental arrangement has been developed to explore the thermoacoustic properties of stack materials. The apparatus may be viewed either as a thermoacoustic engine with two microphones mounted in the tube wall, or as a two-microphone impedance tube that accommodates thermoacoustic elements.
Timothy Simmons, Richard Raspet, Robert Hiller   +2 more
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Impedance tube technology for flow acoustics

Journal of Sound and Vibration, 1981
Acoustic impedance of a termination, or of a passive subsystem, needs to be measured not only for acoustic lining materials but also in the exhaust systems of flow machinery, where mean flow introduces peculiar problems. Out of the various methods of measurement of acoustic impedance, the discrete frequency, steady state, impedance tube method [1] is ...
Panicker, VB, Munjal, ML
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