A numerical study on mixed-phase/glaciated icing in a turbofan engine

Warm airflow inside an engine causes ingested ice crystals to partially melt into water, which can freeze on internal blades, potentially causing engine surge, flameout, and structural damage. In this study, a numerical simulation method was employed to conduct calculations on the mixed-phase/glaciated icing of the low-pressure compressor fan and the booster stage of a certain type of turbofan engine. It considers energy exchange between non-spherical ice crystals and airflow, and investigates the effects of the liquid water content to total water content (LWC/TWC) ratio, ice crystal equivalent diameter, and ice crystal erosion on icing characteristics. The results show that the presence of ice crystals causes an average decrease in 8.63 K in the total air temperature in the booster stage. When LWC/TWC = 11.1%, the average sticking fraction and icing range of each stage increase by 14.9% and 17.72%, respectively. Severe icing occurs even when LWC/TWC = 0, reaching a maximum thickness of 14.51 mm. Doubling the diameter decreases the average temperature and melting fraction of the ice crystals at all stages by 5.28 K and 11.3%, respectively. From the second-stage rotor to the third-stage stator, the icing range and the total mass of ice decrease by 32.26% and 54.18%, respectively. The erosion effect of ice crystals reduces the icing range, total mass of ice and average icing thickness between the second-stage stator to the third-stage stator by 27.8%, 20.04%, and 0.72 mm, respectively. The relevant results provide a reference for understanding the ice crystal icing characteristics within the aero-engine.