scholarly journals Bandwidth Enhancement of a Broadband Ultrasonic Mosaic Transducer using 48 Tonpilz Transducer Elements with 12 Resonance Frequencies

2014 ◽  
Vol 47 (3) ◽  
pp. 302-312
Author(s):  
Dae-Jae Lee
Keyword(s):  
Bandwidth Enhancement ◽  
Resonance Frequencies ◽  
Mosaic Transducer

Plane Wave Resonance in the Tire Air Cavity as a Vehicle Interior Noise Source

1995 ◽  
Vol 23 (1) ◽  
pp. 2-10 ◽  
Author(s):  
J. K. Thompson
Keyword(s):  
Closed Form Solution ◽  
Form Solution ◽  
Interior Noise ◽  
Cavity Resonance ◽  
Test Results ◽  
Vehicle Interior ◽  
Air Cavity ◽  
Vehicle Interior Noise ◽  
Wave Resonance ◽  
Resonance Frequencies

Abstract Vehicle interior noise is the result of numerous sources of excitation. One source involving tire pavement interaction is the tire air cavity resonance and the forcing it provides to the vehicle spindle: This paper applies fundamental principles combined with experimental verification to describe the tire cavity resonance. A closed form solution is developed to predict the resonance frequencies from geometric data. Tire test results are used to examine the accuracy of predictions of undeflected and deflected tire resonances. Errors in predicted and actual frequencies are shown to be less than 2%. The nature of the forcing this resonance as it applies to the vehicle spindle is also examined.

Graphic method for assessing the margins of resistance to acoustic vibrations in the chambers of rocket engines by combustion noise

2020 ◽  
pp. 15-21
Author(s):  
R.A. Tsarapkin ◽  
V.N. Ivanov ◽  
V.I. Biryukov
Keyword(s):  
Rocket Engine ◽  
Spectral Characteristics ◽  
Combustion Process ◽  
Combustion Noise ◽  
Rocket Engines ◽  
Acoustic Vibrations ◽  
Statistical Regression ◽  
Unknown Parameters ◽  
Damping Decrement ◽  
Resonance Frequencies

An experimental method is proposed for estimating the damping decrements of pressure fluctuations in the combustion chambers of forced rocket engines. The method is based on the statistical processing of noise pressure pulsations in the vicinity of natural resonance frequencies for normal modes of acoustic vibrations of the reaction volume and the subsequent prediction of the instability of the combustion process relative to acoustic vibrations. Based on the theory of statistical regression for multidimensional experimental data, the problem of predicting unknown parameters of sample distributions is solved by asymptotic determination of the correlation coefficient of the damping decrement of pressure vibrations through optimal linear predictors and the Kolmogorov distribution. Keywords rocket engine, combustion chamber, acoustic vibrations, combustion noise, spectral characteristics, Kolmogorov criterion, damping decrement. [email protected]

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