Vibration in Pipe » Acoustic Induced Vibration

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Acoustic Induced Vibration (AIV)

INERTANCE has performed Acoustic induced vibration study(AIV) for pipe system, and has provided the best solution to prevent the likelihood of acoustic fatigue failure caused by acoustic excitation as per Energy institute guidelines. This assessment is one of sound analysis for high frequency acoustic excitation in piping system. 

FEM for Acoustic induced vibration
[ O-let Design for AIV ]

Sound Analysis for Acoustic Fatigue

INERTANCE has a capability to perform below kinds of acoustic induced vibration analysis.

  • Acoustically induced vibration (AIV)
  • Acoustic fatigue in pipes
  • High frequency acoustic excitation source
  • Sound power level (PWL)
  • Small bore connection analysis
  • Pressure let-down device (Control valve, pressure relief valve, pressure safety valve, orifice, etc)
  • As per API 521, Concawe report no, 85/82
  • Pipe geometry parameter
  • Pipe energy parameter (Mach number)
  • Sound analysis for acoustic fatigue
  • Noise calculation as per IEC
  • Likelihood of failure assessment
  • Acoustic induced vibration control measures
  • Fitting type: Weldolet, sweepolet, equal tee, reduced tee, nipolet, latrolet, etc
  • Gusset support, reinforced pad, etc
  • Energy institute guideline, Guidelines for the avoidance of vibration induced fatigue failure in process pipework, 2nd edition
  • Detail FEA assessment
Stress by Acoustic Ftigue, Energy institute
[ AIV Fatigue Assessment ]

As per Energy Institute Guidelines

Pressure reducing system such as control valve and pressure safety valve in piping system is subject to rapidly decreasing pressure by flow restriction, which create the high velocity fluid, turbulent mixing and may cause the acoustic energy. The sound power levels are calculated as per process condition, and it is key parameters in problem concerning acoustically induced vibration.

Sound analysis as per Energy Institute guidelines
[ Sound analysis as per Energy Institute guidelines ]

Pipe Geometry for Acoustic Fatigue Control

Pipe diameter and thickness has to be checked in order to screen the potential fatigue failure caused by AIV, as the fatigue failure is more prevalent with thin wall and large diameter pipe. The acoustic energy generated from pressure let-down device is propagated to downstream piping system, and the fitting type and branch size have to be evaluated on the piping discontinuities location.

O-let, Energy institute
[ O-let for AIV ]

* Kinds of fitting type for acoustic induced vibration: Equal tee, Reduced tee, Lateral, Inserted weldolet, Latrolet, Weldolet, Reinforcing pad, Vesselet, Nipoflange, Nipolet, Sweepolet

High Frequency Acoustic Excitation

Acoustic spectrum of pressure let-down device generally have a broad band range with peak frequency in excess of 1000 Hz, which is radiated into the downstream piping. This kinds of high frequency acoustic excitation is the main reasons for acoustic fatigue failure, and the mitigation measures has to be considered to minimize the piping system stress.

Finite element analysis for AIV (Acoustic excitation)
[ Finite element analysis for AIV (Acoustic excitation) ]

Reference for AIV Analysis

Acoustic induced vibration study
[ AIV study ]
Acoustic induced vibration FEM
[ Acoustic induced vibration FEM ]
AIV analysis
[ AIV analysis ]
AIV Study
[ AIV Study ]

INERTANCE has a capability regarding noise and vibration engineering, and our experts are familiar with assessment of Acoustic induced vibration (Acoustic fatigue) study.

For further information, contact us at (admin@inertance.com).

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