Advanced Techniques for Pressure Pulsations Modeling in Volumetric Compressor Manifolds

Pressure pulsations in volumetric compressor manifolds are one of the most important problems occurring in the compressor installations. They cause noise and vibrations, which may result in installation failures. In 2005 DOE USA (Advanced Reciprocating Compression Technology (ARCT), 2005, Final Report SwRI® Project No. 18.11052, DOE Award No. DE-FC26-04NT42269) published a report where pressure pulsations attenuation is named as one of the three most important problems in compressor plants design and operation. Three main approaches of modeling acoustic wave can be named here: one dimensional pipeline modeling with real domain solution and finite difference methods, Helmholtz theory based acoustic model, where complex Fourier transform is used, or finally full computational fluid dynamics (CFD) multidimensional approach. All of them have limited capabilities. With one dimensional model no real geometry of an oil separator or a damper can be introduced. In the Helmholtz approach apart from the length limit of a pipe, complex geometry requires transmission properties of the element. CFD is the most accurate but very time consuming in both computational time and data preparation for the CFD software. In the present paper, one of the coupling methods is shown with the introduction of transmittance characteristics. The resulting simulation using generalized Helmholtz model shows much better agreement with the experimental results than for the classic Helmholtz modeling.