scholarly journals Determination of Seismic Safe Distances During Mining Blasts with Consideration of a Dominant Vibration Frequency

2016 ◽  
Author(s):  
Aleksey Novinkov ◽  
Aleksandr Tashkinov ◽  
Sergey Protasov
Keyword(s):  
Vibration Frequency ◽  
Dominant Vibration Frequency

Temperature during the vibration-assisted compression of alfalfa

BioResources ◽  
2020 ◽  
Vol 16 (1) ◽  
pp. 141-150
Author(s):  
Xiaoyu Wu ◽  
Shuai Yang ◽  
Chundong Song ◽  
Kun Ding ◽  
Chuanzhong Xuan ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Vibration Frequency ◽  
Experimental Results ◽  
Maximum Temperature ◽  
Compression Time ◽  
Vibration Parameters ◽  
Reducing Energy ◽  
Compression Temperature

Compression of alfalfa into briquettes is an effective way to solve the problem of storage and transportation. In the process of compression, heat is generated and the temperature is raised in the material. In fact, the appropriate temperature can improve the quality of alfalfa briquettes and reduce the energy consumption of densification. In this study, the effect of assisted vibration on the compression temperature was tested. The results showed that when the vibration frequency was below 15 Hz, the temperature at the center and side in compressed alfalfa increased slowly with compression time. When the vibration frequency was above 20 Hz, it increased first and then decreased with the increase of time. Moreover, the maximum temperature value increased remarkably when the frequency was above 20 Hz. In the same vibration frequency and compression time, the center temperature in the compressed alfalfa was higher than the side temperature. The experimental results provide a reference for the determination of reasonable vibration parameters, and explanation of the effect of vibration on reducing energy consumption.

Experimental Investigation on Vortex-Induced Vibration of Dual Pipes With Unequal Diameters in Tandem

2020 ◽  
Author(s):  
Mengmeng Zhang ◽  
Shixiao Fu ◽  
Zhiqi Zhang ◽  
Haojie Ren ◽  
Yuwang Xu
Keyword(s):  
Vibration Frequency ◽  
Reynolds Numbers ◽  
Superposition Method ◽  
Wall Surface ◽  
Flexible Pipes ◽  
Modal Superposition Method ◽  
Out Of Plane ◽  
Single Pipe ◽  
Dominant Vibration Frequency ◽  
Significant Interference

Abstract With the massive use of buddle risers and pipelines in deep-water oil production industries, the demand to focus on the research of interference effects of dual pipe has been greatly enhanced. This paper presents interference experiments of dual flexible pipes with unequal diameters under uniform flow with Reynolds numbers ranging from 1.8E3 to 1.1E4. The pipe with larger diameter was set to be the upstream pipe. Various tandem arrangements with wall surface-to-wall surface distances being 3D to 8D were tested, where D is the smaller pipe diameter. Fiber Bragg grating (FBG) strain sensors were used to measure both in-plane and out-of-plane strain responses. Modal superposition method was applied to reconstruct IL mean displacement. Significant interference effect was found under the condition that wall-to-wall gap is smaller than 8D, where CF and IL vibration frequency ratio of downstream pipe equals to 1.0 and IL mean displacement gets smaller compared to those of single pipe in isolation. Moreover, a special ‘capture’ phenomenon, that the dominant vibration frequency and mode of downstream pipe were as the same as that of the upstream pipe subjecting to the uniform flows, was found when wall-to-wall distances were 4D and 8D.

Determination of vibration frequency depending on abrasive mass flow rate during abrasive water jet cutting

2014 ◽  
Vol 77 (1-4) ◽  
pp. 763-774 ◽  
Author(s):  
Pavol Hreha ◽  
Agáta Radvanská ◽  
Sergej Hloch ◽  
Vincent Peržel ◽  
Grzegorz Królczyk ◽  
...  
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Vibration Frequency ◽  
Water Jet ◽  
Abrasive Water Jet ◽  
Water Jet Cutting ◽  
Abrasive Water Jet Cutting

scholarly journals New method for particulate matter measurement with TEOM diesel particulate mass monitor

2007 ◽  
Vol 130 (3) ◽  
pp. 48-51
Author(s):  
Peter GOLOMB
Keyword(s):  
Particulate Matter ◽  
Vibration Frequency ◽  
New Method ◽  
Diameter Distribution ◽  
Exhaust Gas ◽  
Diesel Particulate ◽  
System A ◽  
Particulate Mass

In the paper the Author pointed out, that the major number of the Particulate Mater in the exhaust gas of engines riches the sizes of less than 0.1 μm. For the better determination of the PM diameter distribution the Horiba enterprise has proposed new metering method of the gravimetric type named TEOM. In the metering system a set of fi lters with different fl ow capacity has been applied. The mass of Particulate Metter hold-up on every filter is being determined by the analysis of the filter vibration frequency. The presented method allows the measurements of the PM-mass with the accuracy of 0.01 mg up to few grams.

scholarly journals Identification of the vibration frequency and form of the AWJ machine in aspect of cutter head vibration

Mechanik ◽  
2017 ◽  
Vol 90 (10) ◽  
pp. 876-878
Author(s):  
Tomasz Wala ◽  
Krzysztof Lis
Keyword(s):  
Modal Analysis ◽  
Vibration Frequency ◽  
Experimental Modal Analysis ◽  
Abrasive Waterjet ◽  
Machine Construction ◽  
Tool Support ◽  
Modal Properties ◽  
Cutter Head ◽  
Comprehensive Study

As part of a comprehensive study of influence of vibrations on the abrasive waterjet process, this article discusses about the identification of modal properties of the waterjet machine including the cutter head. The experimental modal analysis of the main gantry components of the machine construction was carried out, i.e. the carrier beam with the tool support and the cutter head. Determination of the modal properties of the machine allowed the identification of these vibrations, which are directly attributable to the construction of the machine and indicate them in the signal registered during the cutting.

Determination of fundamental coupled torsional—radial frequency of single-walled carbon nanotubes

2020 ◽  
pp. 107754632098134
Author(s):  
Sneha Singh
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Shear Modulus ◽  
Vibration Frequency ◽  
Single Walled Carbon Nanotubes ◽  
Radial Vibration ◽  
Single Walled Carbon Nanotube ◽  
Single Walled Carbon ◽  
Walled Carbon Nanotubes

Research indicates that single-walled carbon nanotubes have a unique coupled torsional–radial vibration as one of their fundamental modes. Determination of their vibration frequency is required for efficient use of single-walled carbon nanotube in nano-electromechanical systems. However, there is no mathematical expression for these frequencies and their dependence on single-walled carbon nanotube geometry is unknown. This article examines the effect of diameter, length, and chirality on the fundamental coupled torsional–radial vibration frequency of single-walled carbon nanotube using molecular–structural–mechanics–approach, finite element analysis, and regression analyses. Consequently, a first-ever mathematical form of this frequency is derived. The form quickly and accurately predicts these frequencies at 1.5% in-sample, and 7.2% out-sample mean absolute percentage error. single-walled carbon nanotubes’ fundamental coupled torsional–radial vibration frequency is found independent of diameter and inversely proportional to length where the proportionality constant depends on chirality. The coupling of modes and the similarity of the frequency form with cylindrical shell suggest that single-walled carbon nanotube behave like thin shells in these vibrations. A form for effective circumferential shear modulus of single-walled carbon nanotube is also derived. This modulus is found to depend only on the chirality where achiral single-walled carbon nanotubes have higher values than chiral single-walled carbon nanotubes. Proposed mathematical forms can be used for characterization of single-walled carbon nanotubes, determination of single-walled carbon nanotubes’ effective shear modulus, and tuning operational frequency of single-walled carbon nanotube-based nano-electromechanical systems.

scholarly journals The Method of Accurate Determination of Frequencies and Modes of Vibration of the Resonator of the Vibration Frequency Sensor

2019 ◽  
pp. 16-21
Author(s):  
O. Oliynyk ◽  
Y. Taranenko
Keyword(s):  
Vibration Frequency ◽  
Accurate Determination ◽  
Accurate Method ◽  
Approximate Methods ◽  
Design Work ◽  
Frequency Sensor ◽  
Modes Of Vibration ◽  
Basic Equations ◽  
The Ideal

The article is devoted to the development of an accurate method for determining the frequencies and vibration modes of a resonator of a vibration-frequency sensor by applying an exact simplification of the basic equations of resonant oscillations of a resonator taking into account the rigidity (compliance) of the supports and their location. The deviation of the parameters of the geometry of the resonator from the ideal and the heterogeneity of the material of the resonator affect the metrological characteristics of the vibration frequency sensor. However, existing technologies do not provide the possibility of manufacturing resonators with nominal parameters. The existing numerous algorithms for calculating the frequencies and waveforms of resonators are used to estimate the fundamental frequency of an oscillating system that do not take into account the dynamic characteristics. The accuracy of the oscillation frequency of the resonator depends on the choice of the mode of oscillations, which is sometimes difficult to predict in advance. Practical tasks require performing design work with the required accuracy. The lack of an accurate method for determining the frequencies and modes of vibration of the resonator of the vibration-frequency sensor, which would take into account the type of mounting and location of resistance, designers have to adapt existing approaches and calculation models to specific measurement conditions. Therefore, in practice, simplified and approximate methods of calculation are used. In the presence of concentrated masses and in the case of taking into account energy dissipation in the places where the resonator is fixed, the calculation methods become more laborious. In some cases, the possibility of a mathematical interpretation of a task becomes feasible only if some simplifications are introduced into the calculation.

scholarly journals The Concept of Monitoring Blades of Rotor Machines with the Identification of their Vibration Frequency

2017 ◽  
Vol 44 (1) ◽  
pp. 389-412
Author(s):  
Edward Rokicki ◽  
Paweł Lindstedt ◽  
Jerzy Manerowski ◽  
Jarosław Spychała
Keyword(s):  
Vibration Frequency ◽  
Direct Determination ◽  
Technical Condition ◽  
Parameter Analysis ◽  
Diagnostic Model ◽  
Blade Vibration ◽  
Blade Tip ◽  
Instantaneous Speed ◽  
Amplitude Amplification

Abstract The paper presents the basis of a new method for monitoring the technical condition of rotating blades during their operation. Utilizing the measurement of blade tip instantaneous speed under subsequent sensors, enables direct determination of the blade vibration frequency. The method utilizes a diagnostic model in the form of amplitude amplification W2ij and phase shift φij of a diagnostic signal y(t) resulting from the operation of the blade and the signal from its environment, when the blade tip passes under a cascade of blade tip instantaneous speed sensors. The adopted diagnostic model, indirectly takes into account the current surrounding of a blade without the need to measure it [12, 14]. Evaluation of the blade technical condition in real time and static analysis shall be performed on the basis of the vibration process parameter analysis. The suggested method may play an important role in the diagnostics of rotor machine blades during their operation.

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