Department of Mechanical Engineering
PRESENTATION: Inflight icing and heavy rainfall pose significant hazards to aircraft and aero-engine operations, leading to aerodynamic performance degradation, propulsion efficiency loss, and increased risks to flight safety. This presentation introduces recent research efforts aimed at elucidating the fundamental physics of adverse weather interactions with aircraft and propulsion systems and developing effective mitigation strategies to ensure assured, all-weather flight safety. Comprehensive experimental investigations have been conducted by leveraging the unique Icing/Rainfall Tunnel at Iowa State University (i.e., ISU-IRT) to quantify the key microphysical processes governing dynamic ice accretion over a wide range of icing conditions, from dry rime to wet glaze icing. A suite of advanced flow diagnostic techniques—including PIV, MTV&T, DIP, and high-speed infrared thermography—have been developed and applied to characterize the impingement dynamics of airborne supercooled droplets, transient wind-driven water runback over airframe surfaces, unsteady heat transfer and dynamic solidification processes on rotating fan and propeller blades. Experimental investigations of rain–airfoil and rain–propeller interactions are also performed to elucidate the mechanisms responsible for rainfall-induced aerodynamic penalties. The results reveal how droplet impact, surface water accumulation and transport, and multiphase flow interactions lead to lift reduction, drag increase, and propulsive efficiency degradation under heavy rainfall conditions. Physics-based insights obtained from the experiments are used to evaluate and optimize innovative mitigation approaches, including using state-of-the-art hydro-/ice-phobic coatings and functional surface treatments for passive and hybrid icing protection. Recent efforts to quantify the impacts of icing and heavy rainfall on electric-powered UAV performance are also presented to assess operational limitations and safety risks. The outcomes of the studies provide critical guidance for the design of resilient aircraft and propulsion systems for reliable, efficient, and safe operation of next-generation aircraft and advanced aerial platforms in adverse weather environments.
PRESENTER: Dr. Hui Hu is an Anson Marston University Distinguished Professor in Engineering and Martin C. Jischke Professor in Aerospace Engineering of Iowa State University.His research interests include advanced optical/laser-based diagnostics, aircraft/aero-engine icing and anti-/de-icing; Unmanned-Aerial-Systems (UAS); wind energy and wind turbine aeromechanics; Fluid-Structure Interactions (FSI) of built structures with violent windstorms. Dr. Hu is an ASME Fellow and AIAA Associate Fellow. He is serving as an editor of “Experimental Thermal and Fluid Science-Elsevier” and an associate editor for other 4 international journals. He received several prestigious awards in recent years, including the 2006 NSF-CAREER Award, the 2007 Best Paper in Fluid Mechanics Award (Measurement Science and Technology, IOP Publishing), the 2009 AIAA Best Paper Award in Applied Aerodynamics, the 2012 Mid-Career Achievement in Research Award of Iowa State University, 2013 AIAA Best Paper Award in Ground Testing Technology, 2014 Renewable Energy Impact Award of Iowa Energy Center, 2022 AIAA Best Paper Award on Gas Turbine Engine, and 2023 D.R. Boylan Eminent Faculty in Research Award of Iowa State University.