Experimental Investigation and Modeling of Surge in a Multistage Compressor

Surge is recognized as the most significant flow instability of the compressor as it strongly influences the performance causing pulsations of pressure that generate reversal flow. This phenomenon obviously has to be taken into consideration when designing the compression piping system, upstream and downstream of the compressor. Therefore, the prediction of the transient response of the compressor and the occurrence of surge, with its characteristic oscillations, is a crucial aspect which has acquired high consideration in literature. This paper deals with (i) the experimental analysis of the unstable response of a multistage compressor during surge conditions and ii) the development and tuning of a nonlinear model for simulating the dynamic behavior of the compression system. The dynamic model is implemented in Matlab®/Simulink® environment and developed by means of a general bond graph approach which leads to a highly modular lumped parameter structure.