Results 291 to 300 of about 2,071,116 (352)
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Open Rotor Broadband Interaction Noise
18th AIAA/CEAS Aeroacoustics Conference (33rd AIAA Aeroacoustics Conference), 2012A theoretical model is presented for calculating the broadband noise produced by the interaction of an open rotor with the wake from either an upstream contra-rotating rotor or a stationary pylon. The model is used to investigate the dependence of the radiated noise on parameters such as pylon–rotor gap and the polar and azimuthal directivity of the ...
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Broadband noise in orthorhombic TaS3
Molecular Crystals and Liquid Crystals, 1985We report experimental results on the broadband noise in sliding charge density wave conductor orthorhombic TaS3. We propose that the noise has its origin in the interaction of a deformable condensate with random impurities. The experimental results are in excellent agreement with a phenomenological model based on fluctuations in threshold field due to
O Nark. Rorbins +3 more
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Variable-duration notched-noise experiments in a broadband-noise context
The Journal of the Acoustical Society of America, 1998To model the confusion of short-duration speech signals in noisy environments, it is important to characterize how humans resolve the spectral components of short-duration signals in background noise. Toward that end, a variable-duration notched-noise experiment was conducted in a noise context.
J J, Hant, B P, Strope, A A, Alwan
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Broadband noise and distortion cancelling low noise amplifier
2017 IEEE 60th International Midwest Symposium on Circuits and Systems (MWSCAS), 2017In this paper, a new broadband low noise amplifier (LNA) is proposed. The LNA utilizes a composite NMOS/PMOS cross-coupled transistor pair and a difference amplifier to in-crease the linearity while reducing the noise figure. The introduced approach provides partial cancellation of distortion and noise generated by the input transistors, hence ...
Ahmad Qassem Dawoud +2 more
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Low-Noise Broadband Microbarometers
2009The term infrasound sensor mainly stands for the elements of an infrasound measuring chain, which are located between the wind-generated noise reducer and the recorder. It measures pressure changes over a very large dynamic range and delivers a dynamic signal suited to the associated recorder whose input range is limited.
D. Ponceau, L. Bosca
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Prediction of fan broadband noise
4th AIAA/CEAS Aeroacoustics Conference, 1998The objective of the present work is to develop a complete theory of fan broadband noise in UHBR engines. This paper focuses on dipole broadband noise sources, resulting from the interaction of turbulent inflows with the fan rotor. A modal expansion in a hard-walled duct is used to evaluate the sound power radiated from the sources, taking into account
Benoit d, Michel Roger, Jean Cailleau
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Broadband Low-Noise Amplifiers
2017Although some configurations were already mentioned in Chap. 5 (mostly, feedback configurations), the techniques to turn narrowband LNAs into broadband LNAs are the topic of this chapter. The chapter opens with a discussion of some popular RF broadband topologies, their general circuit diagrams and their advantages and disadvantages.
Mladen Božanić, Saurabh Sinha
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Fan Broadband Interaction Noise Modeling
18th AIAA/CEAS Aeroacoustics Conference (33rd AIAA Aeroacoustics Conference), 2012Results from a detailed investigation into the eect of modeling assumptions used with the RSI method to compute broadband interaction noise downstream of a turbofan engine’s fan stage are presented. The modeling assumptions that are considered include the use of a Green’s function to obtain the exhaust noise from the unsteady vane surface pressure, the
Sheryl Grace +4 more
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Rotor - Stator Broadband Noise Prediction
14th AIAA/CEAS Aeroacoustics Conference (29th AIAA Aeroacoustics Conference), 2008In this paper a semi analytic model for rotor - stator broadband noise is presented. The work can be split into two sections. The first examines the distortion of the rotor wake in mean swirling flow, downstream of the fan. Previous work by Cooper and Peake 4 is extended to include dissipative effects.
Adrian Lloyd, Nigel Peake
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Modeling Broadband Rotor Interaction Noise
17th AIAA/CEAS Aeroacoustics Conference (32nd AIAA Aeroacoustics Conference), 2011A linearized Euler theory is developed for a fan modeled as a rotating annular cascade. The model fully accounts for three-dimensional efiects as well as the additional centrifugal and Coriolis forces. Computations are carried out for a typical fan geometry in nonuniform in∞ow conditions.
Michaela Logue, Hafiz Atassi
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