Designing Piping Systems Against Acoustically Induced Structural Fatigue

1997 ◽  
Vol 119 (3) ◽  
pp. 379-383 ◽  
Author(s):  
F. L. Eisinger
Keyword(s):  
Power Level ◽  
Fluid Pressure ◽  
Acoustic Vibration ◽  
Acoustic Power ◽  
Metal Fatigue ◽  
Operating Life ◽  
Hydrocarbon Gases ◽  
Structural Fatigue ◽  
Inside Diameter ◽  
Piping Systems

Piping systems adapted for handling fluids such as steam and various process and hydrocarbon gases through a pressure-reducing device at high pressure and velocity conditions can produce severe acoustic vibration and metal fatigue in the system. It has been determined that such vibrations and fatigue are minimized by relating the acoustic power level (PWL) to being a function of the ratio of downstream pipe inside diameter D2 to its thickness t2. Additionally, such vibration and fatigue can be further minimized by relating the fluid pressure drop and downstream Mach number to a function of the ratio of downstream piping inside diameter to the pipe wall thickness, as expressed by M2 Δp = f(D2/t2). Pressure-reducing piping systems designed according to these criteria exhibit minimal vibrations and metal fatigue failures and have long operating life.

Acoustically Induced Structural Fatigue of Piping Systems

1999 ◽  
Vol 121 (4) ◽  
pp. 438-443 ◽  
Author(s):  
F. L. Eisinger ◽  
J. T. Francis
Keyword(s):  
Fluid Pressure ◽  
Acoustic Vibration ◽  
Piping System ◽  
Metal Fatigue ◽  
Hydrocarbon Gases ◽  
Structural Fatigue ◽  
Piping Systems ◽  
Geometry Parameter ◽  
Acoustic Fatigue ◽  
The Relationship

Piping systems handling high-pressure and high-velocity steam and various process and hydrocarbon gases through a pressure-reducing device can produce severe acoustic vibration and metal fatigue in the system. It has been previously shown that the acoustic fatigue of the piping system is governed by the relationship between fluid pressure drop and downstream Mach number, and the dimensionless pipe diameter/wall thickness geometry parameter. In this paper, the devised relationship is extended to cover acoustic fatigue considerations of medium and smaller-diameter piping systems.

Acoustic Power and Acoustic Pressure in Piping Systems Handling High Velocity Steam and Gases Through a Pressure Reducing Device

2010 ◽  
Author(s):  
Frantisek L. Eisinger ◽  
Robert Sullivan
Keyword(s):  
High Pressure ◽  
Mach Number ◽  
High Velocity ◽  
Acoustic Pressure ◽  
High Capacity ◽  
Acoustic Power ◽  
Piping System ◽  
Hydrocarbon Gases ◽  
Piping Systems ◽  
Asme Paper

Piping systems handling high-pressure and high-velocity steam and various process and hydrocarbon gases through a pressure reducing device can produce severe vibration of the piping system and noise and pulsation in the surroundings. Utilizing the data published by Carucci, V.A., and Mueller, R.T., 1982, “Acoustically Induced Piping Vibration in High Capacity Pressure Reducing Systems”, ASME Paper No. 82-WA/PVP-8, we develop a relationship for acoustic power and acoustic pressure as a function of the product of the Mach number M and pressure drop Δp (MΔp) through the system. Thirty six cases were evaluated to formulate this relationship.

Evaluation of Representative Piping Systems Designed by Implicit Fatigue Concept

2008 ◽  
Author(s):  
Shin-Beom Choi ◽  
Sun-Hye Kim ◽  
Yoon-Suk Chang ◽  
Jae-Boong Choi ◽  
Young-Jin Kim ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Nuclear Power ◽  
Heat Removal ◽  
Environmental Water ◽  
Lessons Learned ◽  
Metal Fatigue ◽  
Aging Effects ◽  
Age Related ◽  
Piping Systems ◽  
Surge Line

NUREG-1801 provides generic aging lessons learned to manage aging effects that may occur during continued operation beyond the design life of nuclear power plant. According to this report, the metal fatigue, among several age-related degradation mechanisms, is identified as one of time-limited aging analysis item. The objective of this paper is to introduce fatigue life evaluation of representative surge line and residual heat removal system piping which was designed by implicit fatigue concept. For the back-fitting evaluation employing explicit fatigue concept, detailed parametric CFD as well as FE analyses results are used. The well-known ASME Section III NB-3600 procedure is adopted for the metal fatigue and NUREG/CR-5704 procedure is further investigated to deal with additional environmental water effects. With regard to the environmental effect evaluation, two types of fatigue life correction factors are considered, such as maximum Fen and individual Fen. As a result, it was proven that a thermal stratification phenomenon is the governing factor in metal fatigue life of the surge line and strain rate is the most important parameter affecting the environmental fatigue life of both piping. The evaluation results will be used as technical bases for continued operation of OPR 1000 plant.

scholarly journals Supersonic Windtunnel Noise Attenuation

2021 ◽  
Author(s):  
William Wai Lim Wong
Keyword(s):  
Wind Tunnel ◽  
Sound Pressure Level ◽  
Noise Level ◽  
Sound Pressure ◽  
Power Level ◽  
Mesh Size ◽  
Acoustic Power ◽  
Pressure Level ◽  
Supersonic Wind Tunnel ◽  
Acoustic Treatment

The aerodynamic generated noise in the supersonic wind tunnel during operation at Ryerson University has exceeded the threshold of hearing damage. An acoustic silencer was to be designed and added to the wind tunnel to reduce the noise level. The main sources of noise generated from the wind tunnel with the silencer were identified to be located at the convergent divergent nozzle and the turbulent region downstream of the shock wave at the diffuser with the maximum acoustic power level of the entire wind tunnel at 161.09 dB. The designed silencer provided an overall sound pressure level reduction of 21.41 db which was considered as acceptable. Refinement to the mesh size and changes to the geometry of the mixing chamber was suggested for a more accurate result in noise output as well as flow conditions would match up to the physical flow. Additional acoustic treatment should be applied to the wind tunnel to further reduce sound pressure level since the noise level still exceeded the threshold of hearing loss.

Research on Sound Insulation Performance of Poroelastic Material in Complex Structure

2018 ◽  
Vol 911 ◽  
pp. 56-60
Author(s):  
Jun Zhang ◽  
Yi Hang Yu ◽  
Wen Zhong Zhao
Keyword(s):  
Finite Element ◽  
Elastic Modulus ◽  
Transmission Loss ◽  
Complex Structure ◽  
Element Model ◽  
Acoustic Vibration ◽  
Acoustic Power ◽  
Sound Insulation ◽  
Poroelastic Materials ◽  
Flow Resistivity

A finite element model of the double-wall acoustic insulation structure with a air layer and an acoustic absorbent layer made of the poroelastic materials is set up, the responses of this acoustic-vibration system are calculated by using of the direct finite element method when having a diffuse incident acoustic field acting on the incident surface, the radiant acoustic power from the another surface are achieved, then the Transmission Loss(TL) are formulated using the incident acoustic power and the radiant acoustic power. The effects of the thicknesses, elastic modulus, flow resistivity and viscous lengths of the poroelastic materials on TL are analyzed. The results show that the thicknesses and elastic modulus have a significant effects on TL, TL are enhanced with the thicknesses increasing of the poroelastic materials layers, a 4.9dB addition of TL is achieved when thickness is added from 2cm to 3cm; TL are enhanced with the reduction of the elastic modulus in considered frequency range, and TL are reduced with the declining of viscous lengths and with the addition of the flow resistivity when the frequencies are higher than 600Hz.

Relating ASME Flaw Evaluation to ASME Task Group on Carbon Fiber Repairs

2017 ◽  
Author(s):  
Tomas Jimenez ◽  
Eric Houston ◽  
Nico Meyer
Keyword(s):  
Carbon Fiber ◽  
Nuclear Power ◽  
Nuclear Regulatory Commission ◽  
Fiber Reinforced Polymers ◽  
Structural Factors ◽  
Operating Life ◽  
The Us ◽  
Piping Systems ◽  
Wave Passage ◽  
Regulatory Commission

As most nuclear power stations in the US have surpassed their initial 40 years of operability, the industry is now challenged with maintaining safe operations and extending the operating life of structures, systems and components. The US Nuclear Regulatory Commission (NRC), Nuclear Energy Institute (NEI), and Electric Power Research Institute (EPRI) have identified safety related buried piping systems as particularly susceptible to degradation. These systems are required to maintain the structural factors of the ASME Construction Codes under pressure and piping loads, which includes seismic wave passage. This paper focuses on evaluation approaches for metallic buried piping that can be used to demonstrate that localized thinning meets the requirements of the Construction Code. The paper then addresses a non-metallic repair option using carbon fiber reinforced polymers (CFRP) as the new pressure boundary.

scholarly journals A comprehensive investigation of acoustic power level in a moderate or intense low oxygen dilution in a jet-in-hot-coflow under various working conditions

2019 ◽  
Vol 93 ◽  
pp. 105339 ◽  
Author(s):  
Seyed Mahmood Mousavi ◽  
Reza Kamali ◽  
Freshteh Sotoudeh ◽  
Reza Pourabidi ◽  
Nader Karimi ◽  
...  
Keyword(s):  
Working Conditions ◽  
Power Level ◽  
Acoustic Power ◽  
Low Oxygen ◽  
Comprehensive Investigation

An Acoustic Criterion for the Whistling of Orifices in Pipes

2007 ◽  
Author(s):  
P. Moussou ◽  
Ph. Testud ◽  
Y. Aure´gan ◽  
A. Hirschberg
Keyword(s):  
Pressure Drop ◽  
Plane Waves ◽  
Acoustic Scattering ◽  
Acoustic Power ◽  
Acoustic Boundary Conditions ◽  
Acoustic Feedback ◽  
Single Hole ◽  
Piping Systems ◽  
Inner Diameter ◽  
Acoustic Amplifier

Whistling due to vortex shedding has been extensively studied in the case of cylinders in cross-flows, of flow separation above cavities and of shear layers with flow impingement feedback. Less attention has been given to pressure drop devices in piping systems, which are known to generate high noise levels due to single tones in gas systems, and even in water systems. Based on recent work of Auregan et Starobinski (1999), an experimental criterion is proposed to evaluate the whistling ability of a pressure drop device in the presence of plane waves acoustic feedback. The idea of the criterion can be summarized as follows: if for a given combination of incident pressure waves, the amount of acoustic power scattered is higher than the incident one, the pressure drop device behaves as an acoustic amplifier, so that whistling can occur if the adequate acoustic boundary conditions are met. The main advantage of this criterion is that it depends only on the acoustic scattering matrix of the device, rather than on the acoustics of the surrounding pipe. Results obtained in an air test rig with an inner diameter of 3 cm, a Mach number varying from 10−3 to 10−1 and a Reynolds number varying from 103 to 105 are reported for single hole orifices. Basing the Strouhal number on the thickness of the orifice and on the average velocity through the hole, thin single hole orifices with sharp angles appear to whistle at Strouhal numbers close to 0.2. Furthermore, it is shown that a thin orifice with a downstream bevel is prone to whistling, whereas the same orifice with the bevel upstream cannot whistle.

Spectral Properties and Quantitative Evaluation of Hypernasality in Vowels

1996 ◽  
Vol 33 (1) ◽  
pp. 43-50 ◽  
Author(s):  
Ryuta Kataoka ◽  
Ken-Ichi Michi ◽  
Kaoru Okabe ◽  
Tanetoshi Miura ◽  
Hiroshi Yoshida
Keyword(s):  
Spectral Properties ◽  
Power Level ◽  
Power Spectra ◽  
Normal Subjects ◽  
Acoustic Power ◽  
Preliminary Study ◽  
A New Technique ◽  
Second Formant ◽  
The One ◽  
Nasal Resonance

A new technique for evaluating hypernasality using an acoustic approach is presented. In a preliminary study using this technique, nasal resonance was assessed in 17 normal subjects and 16 subjects judged to be hypernasal. Analyses of the one-third-octave power spectra revealed an increase in power level between the first and second formant, and a reduction in the power level in second and third formant regions among utterances judged to be hypernasal. Factor analysis of the perceptual ratings revealed that the consensus perception of hypernasality accounted for 71% of the total variance. An additional 8% was accounted for by individual differences. Multiple regression analysis revealed a high correlation between the consensus perception of hypernasality and the variance in two acoustic-power levels, these being the power level between the first and second formant and the power level of the second and third formant regions.

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