Pressure pulsations in piping systems excited by a centrifugal compressor (3rd report, the characteristics of the pressure pulsations in the drum connected to the piping system)

The characteristics of the pressure pulsations in the drum connected to the piping system excited by centrifugal compressors or blowers at blade-passing frequency were investigated. In this study, the equivalent resistance of a compressor and that of piping systems were introduced to the three dimensional calculation model, so that the non linear damping proportional to velocity squared in the system is properly incorporated. As a result, the pressure response in the drum as well as pipe can be well evaluated by this model. Furthermore, the effect of the acoustic dynamic absorber on the pressure pulsations in the pipe and drum is evaluated. It is shown that the maximum pressure amplitude in the drum is obtained when the resonant frequency in the pipe is slightly shifted from the resonant frequency in the drum under the small damping conditions. The effect of the damping in the drum and the mode shape in the drum on the maximum pressure amplitude in the drum is discussed.