### ASA 124th Meeting New Orleans 1992 October

## 1pPAb8. Acoustic transfer impedance of a complex piping system.

**Limin Song
**

**
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*Eng. Dept., Mobil Res. and Develop. Corp., P.O. Box 1026, Princeton, NJ
08543
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A transfer impedance method has been developed to analyze the acoustic
response of a complex piping system to low-frequency pulsation sources such as
a reciprocating compressor. The acoustic transfer impedance of a piping system
is defined as the complex amplitude of acoustic pressure in the piping system
generated by a constant-frequency source at a given location that has a unity
complex amplitude of acoustic volume velocity. In this method, the transfer
impedance in each pipe component is expressed in terms of transmission and
reflection coefficients that are determined through boundary conditions.
Recurrence relations are derived to relate the transmission and reflection
coefficients of one pipe component to those of an adjacent pipe component. This
method is particularly useful in analyzing piping acoustic resonance and
pulsation mode shape in which the location of maximum acoustic pressure can be
easily identified. If the pulsation source is known, the pulsation levels in
the piping system can be calculated. Compared with most of existing methods,
this method provides a better understanding on how acoustic energy propagates
in the piping system in addition to giving a quicker and simpler solution.
Further development of this method may lead to design optimization of pulsation
control devices.