Dynamic analysis of air system with fast transients in shaft failure event

This study established the governing equations and the corresponding modularized simulation model for air system in rapid transients. The modularized model consists of four kinds of basic components that constitute the transient air system network: pressure vessels, nodes, ducts, and throttles. The validation of the modular components and their assemblies against published data has been demonstrated to be successful. The model is proved to be able to handle volume packing effects and flow inertia effects that account for the main contributions to fast transient scenarios. On this basis, the model is utilized to analyze the flow evolution of air system in aero engine high pressure turbine (HPT) shaft failure event. The results show that the shaft failure can lead to complex dynamic response in the air system and the subsequent reversal of the turbine disk endload. The model established in this study successfully predicts the air system transient response within millisecond time scales, which provides an effective approach to gain insight into the complex transient mechanism of aero engine air system.