The role of volume effect on the transient behavior of a transonic compressor

Abstract

Abstract The significance of the volume effect on the compressor performance during acceleration and deceleration has received limited attention, despite its demonstrated importance in compressor flow instabilities. To better understand this effect, the in-house simulation program CAM (a modular transient simulator) is used to investigate the volume effect on the compressor transient performance. The modeling procedure is derived from Greziter’s lumped parameter approach and the accuracy of the simulation model is verified by experimental data. This study presents a comprehensive comparison and explanation of variations in compressor transient behavior observed under different conditions, including different shaft speed change rates, compressor volume sizes, and operating speeds. The relative difference between the compressor inlet and outlet mass flow is identified as the key factor contributing to these discrepancies. In addition, a simplified analytical model is developed to provide a basic description of the compressor operating line during acceleration and deceleration, which also provides additional support for the validity of the numerical results. This study systematically establishes the dynamic dependencies between shaft speed change, pressure and mass flow change, offering critical information for ensuring the safety of compressors during transient operation.