Modeling and validation of the volume effect on the axial fan transient performance

Abstract Since Professor Greziter first proposed a theoretical model to predict the dynamic behavior of a compression system in 1976, the contribution of the volume effect to compressor flow instabilities has been widely studied, but the role of volume effect on the compressor performance during acceleration and deceleration has not received much attention. Therefore, starting from the Greitzer lumped parameter approach and integrating with real engine simulated components to improve the Greitzer’s model, an engine transient simulation model accounting for the compressor volume effect (referred to as the unsteady model) is developed in this paper. Based on a real turbofan engine, transient examination comprising acceleration and deceleration has been conducted for the validation of the unsteady model. The simulation results show better agreement with the experimental data compared with the transient simulation without considering the compressor volume effect (referred to as the quasi-steady model), which confirms the importance of introducing the compressor volume effect into the engine transient modeling. And the cause of the deviation between unsteady model and quasi-steady model are further explained by the compressor inlet and outlet mass flow curve. The results may further contribute to the development of engine transient model.