Thermal Physics of Aircraft Ice Accretion



题目:Thermal Physics of Aircraft Ice Accretion
报告人:Dr. Yiqiang Han
Clemson University, USA


    Aircraft icing has been on US National Transport Safety Board (NTSB)’s “List of most wanted safety improvements” since 1997. Severe inflight icing accidents are almost always associated with fatality, such as Air Asia and Air Algerie accidents in 2014, resulting in 54% of global air crash fatalities of that year. Inflight ice accretion poses significant loss in aircraft performance and thus jeopardizes flight safety. A good understanding of aero-thermal physics related to ice accretion is of great interest for both academia and industry.

In this presentation, comprehensive workflow for developing an improved ice accretion modeling tool will be introduced. Novel techniques, such as ice molding and casting methods and transient heat transfer measurement using non-intrusive thermal imaging methods, are developed to aid understanding aero-thermal physics. A heat transfer scaling parameter designed for turbulent flow regime, labeled as Coefficient of Stanton and Reynolds Number (CSR = St/Re-0.2), will be validated. By coupling with LEWICE (an industry-standard icing prediction tool developed at NASA Glenn Research Center), the ice shape prediction results showed significantly improved accuracy. Rotor torque predictions coupling with Blade Element Momentum Theory (BEMT) compared to 17 validation measurements will also be demonstrated. The coupled torque prediction tool achieves a 9.8% predicting error for clean rotor conditions, and 15.6% error for iced rotor conditions.

    Ongoing projects will also be shared with audience at the end of the presentation. These efforts will greatly expand the envelope for current aircraft icing research and also extend the application to other disciplines, which will generate fruitful collaborations. Besides conventional icing research for super-cooled large droplets (SLD), other types of icing research, such as engine ice crystal problem monitoring, helicopter rotor noise due to icing, wind turbine icing, high-speed impact fragmentation of foreign objects, will be discussed.