Qualitative and quantitative analysis of Chinese herb fructus chaenomelis

Du, Shouying; Chen, Lina; Ma, Ke; Ji, Hongjian

doi:10.1016/s1007-4376(07)60012-4

Cited by 21 publications

(26 citation statements)

References 2 publications

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“…(2) Sound pressure level The hydrophone is affected by the hydroacoustic sound pressure P in the sound field, which generates an open-circuit voltage U. The open-circuit voltage U is proportional to the sound pressure P. Therefore, the hydrophone sensitivity M can be obtained as [27]:…”

Section: Test Methodsmentioning

confidence: 99%

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Effect of Vibration and Noise Measuring Points Distribution on the Sensitivity of Pump Cavitation Diagnosis

Zhou¹,

Chen²,

Liu³

et al. 2022

sv-jme

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Cavitation is an essential factor in the deterioration of the hydraulic performance of centrifugal pumps. The study of cavitation fault diagnosis can help avoid or reduce the damage it causes. The vibration and noise analysis method can predict the incipient cavitation more accurately. In order to improve the accuracy of cavitation fault diagnosis, this paper studies the distribution of vibration and noise measuring points for centrifugal pump cavitation diagnosis. The research object is a centrifugal pump with an inducer and splitter blades. Vibration acceleration sensors and hydrophones were used to collect structural vibration and liquid-borne noise signals at different positions of the pump unit. Root-mean-square (RMS) and fast Fourier transform (FFT) methods were used to construct spectrums of vibration and noise signals with different NPSH and compare the sensitivity of different measuring points to the inception and development of cavitation. In addition, the SST k-ω turbulence model and Zwart cavitation model were used to study the cavitation volume distribution in the pump under different cavitation stages. By setting monitoring points at the impeller outlet, the frequency domain signal distribution of pressure pulsation was studied. The results show that the vibration acceleration measuring points at the pump inlet flange and pump axial position, and liquid-borne noise measuring point at the inlet position, are more sensitive to the diagnosis of cavitation fault. Motor current is also the basis for judging the inception of cavitation. Moreover, as the cavitation intensifies, the dominant frequency signal of the pressure pulsation in the pump is partially shifted.

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Section: Test Methodsmentioning

confidence: 99%

“…In hydroacoustics, 1 μPa is usually used as the sensitivity reference. The output voltage signal of the hydrophone is processed by the FFT method to obtain the voltage spectrum and logarithmically transform the voltage spectrum to obtain the voltage decibel [27]:…”

Section: Test Methodsmentioning

confidence: 99%

Effect of Vibration and Noise Measuring Points Distribution on the Sensitivity of Pump Cavitation Diagnosis

Zhou¹,

Chen²,

Liu³

et al. 2022

sv-jme

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show abstract

“…(3). Assume that the vibration velocity weighting vector of the transducer array is V W , then the sound pressure in the θ direction on a certain distance from the center of the array can be calculated as follows:…”

Section: Principle Of Boundary Element Model Optimization Methodsmentioning

confidence: 99%

“…Good transmitting beampattern such as a low sidelobe level and high transmitting source level is always expected, thus the transmitting sound energy can be focused in the concerned direction, and the long-range object can be detected with a relatively lower transmitting sound energy [1]. In the research of the radiated acoustic field of compact transducer arrays, the mutual interactions among elements must be considered [2,3,4]. The interactions become more significant when the number of elements increases, the distance among elements is smaller and the sound frequency is lower.…”

Section: Introductionmentioning

confidence: 99%

Investigation of Low-Sidelobe Beampattern Controlling Methods for Acoustic Transmitting Array of Underwater Vehicles

Shi

2017

Polish Maritime Research

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“…Changing rule of strain energy and mechanism of energy mutation were studied during gradual evolution in ref. [10]. A synergy methodology to a multi-objective operational control of reservoirs was put forward based on entropy theory in ref.…”

Section: Establishment Of Deformation Entropymentioning

confidence: 99%

Study on early warning index of spatial deformation for high concrete dam

Peng

Chang

Xiao

et al. 2011

Sci. China Technol. Sci.

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Owing to the deficiency in early warning for high concrete dam, a formula was established to characterize the deformation behavior of high concrete dam as a whole. The early warning index of spatial deformation was calculated by low probability principle on the basis of the deformation entropy formula proposed. The steps were as follows. Firstly, the probability method was utilized to define the degree of order and degree of chaos for each survey point. Secondly, the weight distribution among the survey points was calculated by projection pursuit analysis. Thirdly, the formula of holistic deformation entropy, which can represent the degree of order of high concrete dam, was established on the basis of synergetics and information entropy. Lastly, the early warning index of deformation entropy was computed by low probability method based on series of calculated deformation entropy values. An example showed that the dynamic property of deformation entropy is in accordance with both environmental variables and deflection deformation. Moreover, deformation entropy can be used to improve warning ability and safety management for high concrete dam. deformation entropy, early warning index, synergetics, dam monitoring, concrete dam Citation:Lei P, Chang X L, Xiao F, et al. Study on early warning index of spatial deformation for high concrete dam.

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Qualitative and quantitative analysis of Chinese herb fructus chaenomelis

Cited by 21 publications

References 2 publications

Effect of Vibration and Noise Measuring Points Distribution on the Sensitivity of Pump Cavitation Diagnosis

Effect of Vibration and Noise Measuring Points Distribution on the Sensitivity of Pump Cavitation Diagnosis

Investigation of Low-Sidelobe Beampattern Controlling Methods for Acoustic Transmitting Array of Underwater Vehicles

Study on early warning index of spatial deformation for high concrete dam

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