scholarly journals Using Windowed Interpolation Method to Suppress Power Frequency Noise of Vibration Signal

2021 ◽  
Vol 2095 (1) ◽  
pp. 012057
Author(s):  
Xiaotao Zhang

Abstract Power frequency noise interference is widespread. In order to suppress power frequency noise coupled into vibration signal, windowed interpolating method was studied. Firstly, three typical window functions were compared, including rectangular window, Hanning window and six-term cosine window. Secondly, the numerical simulation method was used to analyze the influence of window function on the interpolation results of power frequency noise, finding that different window function should be chose when the spectrum spacing between power frequency noise and useful components of vibration signal is different. Finally, the windowed interpolation method was applied to actual engineering vibration signal to suppress its power frequency noise, with the result that the interpolation result of vibration signal is the most accurate with Hanning window. Numerical simulation and engineering application show that the windowed interpolation method is effective for power frequency noise suppression.

1994 ◽  
Vol 116 (2) ◽  
pp. 179-187 ◽  
Author(s):  
P. D. McFadden

An existing technique which enables the estimation of the time domain averages of the tooth meshing vibration of the individual planet and sun gears in an epicyclic gearbox from measured vibration signals has been revised. A key feature of the existing technique is the sampling of the vibration signal within a rectangular window in the time domain when one of the planet gears is close to the vibration transducer. The revised technique permits the use of other window functions, and a detailed analysis shows that the errors in the estimate of the time domain average can be expressed in terms of the window function. Several suitable window functions which enable a reduction in the level of the errors are demonstrated by numerical examples and by the analysis of data from a test on a helicopter gearbox with deliberate damage to one of the planet gears.


2011 ◽  
Vol 94-96 ◽  
pp. 2118-2122
Author(s):  
Hong Bin Zhou ◽  
Qiao Zhen Zhang ◽  
Yun Liu ◽  
Jun Ying Dong

In order to solve the insufficient bearing capacity of the large-diameter circular steel tube K-Joints, the chord in the joint zone is filled with the concrete. The reinforcement of bearing capacity that the concrete makes to K-Joints is researched with the finite element numerical simulation method, in consideration of the material nonlinearity and the geometric nonlinearity. The numerical computation of bearing behavior is employed to eighteen groups of the large-diameter circular steel tube K-Joints and reinforced ones with the concrete (RK-Joints). The failure styles and the influencing factors of bearing capacity are analyzed with RK-Joints. The result shows that the bearing capacity of K-Joints is enhanced significantly by the concrete filled in the chord in the joint zone. The load-deformation curves reveal the changing regularity that the bearing capacity of joint follows the relevant parameters. It can provide reference for the engineering application of RK-Joints.


2021 ◽  
Vol 9 (6) ◽  
pp. 680
Author(s):  
Hui Li ◽  
Yan Feng ◽  
Muk Chen Ong ◽  
Xin Zhao ◽  
Li Zhou

Selecting an optimal bow configuration is critical to the preliminary design of polar ships. This paper proposes an approach to determine the optimal bow of polar ships based on present numerical simulation and available published experimental studies. Unlike conventional methods, the present approach integrates both ice resistance and calm-water resistance with the navigating time. A numerical simulation method of an icebreaking vessel going straight ahead in level ice is developed using SPH (smoothed particle hydrodynamics) numerical technique of LS-DYNA. The present numerical results for the ice resistance in level ice are in satisfactory agreement with the available published experimental data. The bow configurations with superior icebreaking capability are obtained by analyzing the sensitivities due to the buttock angle γ, the frame angle β and the waterline angle α. The calm-water resistance is calculated using FVM (finite volume method). Finally, an overall resistance index devised from the ship resistance in ice/water weighted by their corresponding weighted navigation time is proposed. The present approach can be used for evaluating the integrated resistance performance of the polar ships operating in both a water route and ice route.


2017 ◽  
Vol 322 ◽  
pp. 301-312 ◽  
Author(s):  
Susumu Yamashita ◽  
Takuya Ina ◽  
Yasuhiro Idomura ◽  
Hiroyuki Yoshida

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Yijie Shi ◽  
Pengfei Wang ◽  
Ronghua Liu ◽  
Xuanhao Tan ◽  
Wen Zhang

Coalbed water injection is the most basic and effective dust-proof technology in the coal mining face. To understand the influence of coalbed water injection process parameters and coalbed characteristic parameters on coal wetting radius, this paper uses Fluent computational fluid dynamics software to systematically study the seepage process of coalbed water injection under different process parameters and coalbed characteristic parameters, calculation results of which are applied to engineering practice. The results show that the numerical simulation can help to predict the wetness range of coalbed water injection, and the results can provide guidance for the onsite design of coalbed water injection process parameters. The effect of dust reduction applied to onsite coalbed water injection is significant, with the average dust reduction rates during coal cutting and support moving being 67.85% and 46.07%, respectively, which effectively reduces the dust concentration on the working face and improves the working environment.


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