Expansion-chamber muffler for impulse noise of pneumatic frictional clutch and brake in mechanical presses

Zhao, Sheng; Wang, Ji; Wang, Jun; He, Yupeng

doi:10.1016/j.apacoust.2005.09.007

Cited by 13 publications

(10 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…According to Lighthills's theory of aerodynamic noise, the airflow through the throttle is made up of acoustic monopoles induced by a change in the mass flow rate, dipoles showing the effect of constant boundaries on the base field, and turbulence quadrupoles [6,7]. The generated impulse sound can be distinguished by an initial sudden increase due to the large pressure difference and large flux [3], where the value can range from 96 to 120 dBA [8,9], or even up to 130 dBA [10]. Then, there is a gentle decrease due to the smooth reduction in the jet and the pressure difference.…”

Section: Introductionmentioning

confidence: 99%

“…Zhao et. al analysed the two-level exhaust process through expansion chamber mufflers with sound-absorbing stainless steel fiber and a switch valve from pneumatic presses PFC/B [10]. The exhaust air is first expanded into the muffler chamber at a pressure of 1.5-2 bar.…”

Section: Introductionmentioning

confidence: 99%

“…With the decrease in the pressure difference, the noise generation was reduced from 115 to 82 dB. [10]. However, expansion chamber mufflers with a switch valve make the air exhaust process three times longer.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Exhaust Noise Reduction by Application of Expanded Collecting System in Pneumatic Tools and Machines

et al. 2021

View full text Add to dashboard Cite

In this paper, we demonstrate how to reduce the noise level of expanded air from pneumatic tools. Instead of a muffler, we propose the expanded collecting system, where the air expands through the pneumatic tube and expansion collector. We have elaborated a mathematical model which illustrates the dynamics of the air flow, as well as the acoustic pressure at the end of the tube. The computational results were compared with experimental data to check the air dynamics and sound pressure. Moreover, the study presents the methodology of noise measurement generated in a pneumatic screwdriver in a quiet back room and on a window-fitting stand in a production hall. In addition, we have performed noise measurements for the pneumatic screwdriver and the pneumatic screwdriver on an industrial scale. These measurements prove the noise reduction of the pneumatic tools when the expanded collecting system is used. When the expanded collecting system was applied to the screwdriver, the measured Sound Pressure Level (SPL) decreased from 87 to 80 dB(A).

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Exhaust Noise Reduction by Application of Expanded Collecting System in Pneumatic Tools and Machines

et al. 2021

View full text Add to dashboard Cite

show abstract

“…Authors [11][12][13] systematically investigated the exhaust noises generated in pneumatic valves, and generalized noises as stable, periodic and intermittent exhaust noises, according to the timing of the exhaust time. They specified that the valve-caused noise is one kind of IEN.…”

Section: Introductionmentioning

confidence: 99%

“…This noise is characterized by its very short continued time and sharp fluctuation due to the strong airflow shock in the exhaust over a short period of time. Zhao et al [11][12][13] applied Lighthill's aerodynamic noisegenerated theory to the valve-caused noise, and pointed out that its acoustic source is briefly acoustic monopoles and quadrupoles. In the far field, observation of the sound developed by the valve-caused intermittent exhaust noise, a relation of the total SP and airflow physical quantities such as a flow speed was presented, in both low frequency and high frequency bands.…”

Section: Introductionmentioning

confidence: 99%

Prediction of radiation characteristic of intermittent exhaust noise generated via pneumatic value

Hu-shan¹,

Zhao²

2009

Noise Control Eng. J.

Self Cite

View full text Add to dashboard Cite

A mechanism for intermittent exhaust noise (IEN) generation mechanism, and the existing pressure shockwave with the standing-wave variation resulting in the impulse characteristic sound source that sequentially develops the airflowinduced IEN with the much high-frequencies content, is proposed. The shockwave impulse acoustic source (SIAS) describes the impulse sound source caused by the shockwave, conceptually and aerodynamically. Upon analysis of the exhaust noise source distribution in the pneumatic exhaust system via the pneumatic valve, this paper proposes that the SIAS with the maximum amplitude is located at the exhaust outlet; a relation of the noise source and both mass flux and flow speed is set up. With the piston acoustic source approximating the SIAS radiation at the outlet, formulae for calculating the sound pressure (SP) and sound pressure level (SPL) are given. Experiments support the proposed IEN-generation mechanism. The analytical results are in a good agreement with the experimental results in the octave bands, with the difference between the measured and calculated overall A-weighted sound level less than 3 dB. Especially for the octave bands from 250 Hz to 16 kHz, the differences between the measured and calculated A-weighted sound level are less than 3.5 dB. © 2009 Institute of Noise Control Engineering.

show abstract

Analysis on loudness of exhaust noise and improvement of exhaust system based on structure-loudness model

Qiu

et al. 2019

Applied Acoustics

View full text Add to dashboard Cite

The structure of exhaust system influences the loudness of exhaust noise significantly. This paper indicates the impact of the structure parameters of exhaust system on the loudness of exhaust tail noise and presents an evaluation model to conduct the improvement of exhaust system for improved loudness.Firstly, the twenty-seven structure samples are designed by orthogonal experiment and exhaust tail noises of those are obtained by simulation. The accuracy of simulation is also validated by the experiment successfully. Then the structure-loudness model is developed by the radial basis function (RBF) network technique. Subsequently, the contributions and main effects of the structure parameters on loudness are indicated in this work. Finally, based on the structure-loudness model, the robust optimum design for improved loudness is studied by the adaptive simulated annealing (ASA) algorithm.The result of optimization certifies that the structure-loudness model is useful for the optimization. The method applied in this paper can be feasible for other psychoacoustic metrics.

show abstract

Expansion-chamber muffler for impulse noise of pneumatic frictional clutch and brake in mechanical presses

Cited by 13 publications

References 4 publications

Exhaust Noise Reduction by Application of Expanded Collecting System in Pneumatic Tools and Machines

Exhaust Noise Reduction by Application of Expanded Collecting System in Pneumatic Tools and Machines

Prediction of radiation characteristic of intermittent exhaust noise generated via pneumatic value

Analysis on loudness of exhaust noise and improvement of exhaust system based on structure-loudness model

Contact Info

Product

Resources

About