The Development of Icing Experiment Techniques for eVTOL UAM Certifications

Tilt-rotor vehicles are being investigated and developed as an option for Urban Aerial Mobility vehicles. Withe several prototypes being tested or approaching maiden flight, it is important to develop corresponding certification techniques. Icing is an atmospheric threat to the safe operation of UAM vehicles. An icing test campaign is supported by FAA and test articles are designed and fabricated at Penn State. This study reviews the most recent tilt-rotor icing test in the Climatic Wind Tunnel at RTA. A 3-bladed rotor test rig is developed by Penn State and the test rig is installed on a 3-position tilt-table to simulate different stages of UAM flights. The test campaign successfully collect the first batch of rotor performance data points under various icing conditions and two flight conditions. It is observed in the experiment that both thrust and total power are decreasing when the propeller is cruising against the free stream. A fundamental momentum theory model is developed to extract profile power based on measured thrust and profile power, and the extracted profile power increases in all icing cases. In addition to generating baseline data points to verify icing models for UAM, the experiment demonstrates the possibility of certifying UAM rotor/propeller in the Climatic Wind Tunnel at RTA.