Non-intrusive determination of bubble and slug length scales in fluidized beds by decomposition of the power spectral density of pressure time series

This article presents a methodology for selecting the frequency resolution bandwidth for the spectral analysis of stationary random vibration signals in an optimum manner. Specifically, the resolution bandwidth that will produce power spectral density estimates with a minimum mean square error is determined for any given measurement duration (averaging time), and methods of approximating the optimum bandwidth using practical spectral analysis procedures are detailed. The determination of the optimum resolution bandwidth requires an estimate for the damping ratio of the vibrating structure that produced the measured vibration signal and the analysis averaging time. It is shown that the optimum resolution bandwidth varies approximately with the 0.8 power of the damping ratio and the bandwidth center frequency, and the −0.2 power of the averaging time. Also, any resolution bandwidth within ±50% of the optimum bandwidth will produce power spectral density (PSD) estimates with an error that is no more than 25% above the minimum achievable error. If a damping ratio of about 5% for structural resonances is assumed, a constant percentage resolution bandwidth of 1/12 octave, but no less than 2.5 Hz, will provide a near optimum PSD analysis for an averaging time of 2 seconds over the frequency range from 20 to 2000 Hz. A simple scaling formula allows the determination of appropriate bandwidths for other damping ratios and averaging times.

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Determination of the Wenzel roughness parameter by the Power Spectral Density of functional Alumina surfaces

Thin Solid Films ◽

10.1016/j.tsf.2016.03.027 ◽

2016 ◽

Vol 606 ◽

pp. 57-62 ◽

Cited By ~ 8

Author(s):

P.L.G. Jardim ◽

F. Horowitz ◽

N. Felde ◽

S. Schröder ◽

L. Coriand ◽

...

Keyword(s):

Spectral Density ◽

Power Spectral Density ◽

Roughness Parameter ◽

Power Spectral

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A Comprehensive Power Spectral Density Analysis of Astronomical Time Series. I. The Fermi-LAT Gamma-Ray Light Curves of Selected Blazars

The Astrophysical Journal Supplement Series ◽

10.3847/1538-4365/aba2c7 ◽

2020 ◽

Vol 250 (1) ◽

pp. 1 ◽

Cited By ~ 1

Author(s):

Mariusz Tarnopolski ◽

Natalia Żywucka ◽

Volodymyr Marchenko ◽

Javier Pascual-Granado

Keyword(s):

Time Series ◽

Spectral Density ◽

Power Spectral Density ◽

Gamma Ray ◽

Light Curves ◽

Power Spectral ◽

Astronomical Time ◽

Density Analysis ◽

Power Spectral Density Analysis ◽

Astronomical Time Series

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Pewilayahan Siklus Suhu Permukaan Laut di Perairan Indonesia Menggunakan Metode Power Spectral Density (PSD)

PRISMA FISIKA ◽

10.26418/pf.v8i1.40231 ◽

2020 ◽

Vol 8 (1) ◽

pp. 85

Author(s):

Syarifah Resha Fadziella ◽

Yoga Satria Putra ◽

Arie Antasari Kushadiwijayanto

Keyword(s):

Time Series ◽

Fourier Transform ◽

Spectral Density ◽

Fast Fourier Transform ◽

Power Spectral Density ◽

Power Spectral

Penelitian tentang siklus suhu permukaan laut (SPL) dominan terbesar pertama dan kedua di Perairan Indonesia telah dilakukan menggunakan metode Power Spectral Density (PSD) berdasarkan data time series SPL selama 40 tahun (1979-2018). Dari analisis yang dilakukan siklus dominan terbesar pertama adalah siklus 12.15 bulan (annual) dan siklus 6 bulan (semiannual). Siklus 12.15 bulan (annual) cenderung berada di perairan Utara dan perairan Selatan Indonesia sedangkan siklus 6 bulan (semiannual) cenderung berada di kawasan ekuator kecuali perairan Ekuatorial Samudra Hindia. Kemudian, siklus dominan terbesar kedua memiliki beragam periode seperti siklus setengah tahun (semiannual), tahunan (annual) dan siklus antar tahunan (interannual). Siklus setengah tahun (semiannual) berada di perairan Utara dan perairan Selatan Indonesia, siklus tahunan (annual) berada di kawasan ekuator, dan siklus antar tahunan (interannual) berada di perairan Barat Sumatera, Selat Makassar, Teluk Tomini, Laut Halmahera, dan di perairan Papua.Kata Kunci : Suhu permukaan laut, Perairan Indonesia, Power Spectral Density (PSD), dan Fast Fourier Transform (FFT).

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