UAS Embeded Icing Sensor*

As unmanned aircraft begin integration into the National Air Space (NAS), icing hazards for unmanned aircraft systems (UAS) and advanced air mobility (AAM) systems need to be explored. Icing accretion sensors currently in use on manned aircraft are prohibitive due to size, weight, power and cost requirements for SUAS. Additionally, the low velocity and low altitude regime change present different needs from an icing sensor.  

This study details the design and characterization of a low-cost miniaturized ice detection and Liquid Water Content (LWC) sensor that can be embedded into the airfoil of small UAS. This low-cost sensor will allow for the detection of ice accretion on a 12-inch Y-Clark airfoil by monitoring a heating element maintained at 40° Celsius under variable small UAS flight conditions. This study will examine the effects of multiple materials through both direct heating via currents and indirect heating via PCB heaters. By examining the temperature emitted as voltages increase, the most power efficient material can be selected as the heating element for the icing sensor. This study will examine the effect of material choice, voltage, heating method, and shape of heating elements for an airfoil embedded ice accretion sensor. The study will be done in facilities that can simulate the conditions most likely to cause ice accretion on a SUAS. 

The work will be completed with sets of calibration experiments to both explore the physics behind UAS icing flow regime and to allow the sensor to become fully functional. These calibration experiments will be conducted though both Oklahoma State University’s dry air wind tunnel and NASA Glenn’s Adaptive Icing Tunnel for prototype characterization; this will focus on the voltage/power received giving heat transfer and ice heating data. CFD analysis was performed to view the flow patterns of the fluid through the embedded icing sensor. These were done at different angles of attack and in different configurations.