Experimental Investigation on the Dynamic Icing Process over a Rotating Propeller Model

Abstract

An experimental study was conducted to investigate the dynamic ice accretion process over the blade surfaces of a rotating propeller model for unmanned-aerial-system (UAS) applications. In addition to revealing the transient ice accretion process over the rotating propeller surfaces, the dynamic thrust force generated by the propeller model was also measured simultaneously along with the required power inputs to drive the propeller model. Because of the combined effects of aerodynamics forces and the centrifugal force associated with the rotation motion, the ice accretion process over the rotating propeller surfaces was found to become very complicated. The ice accretion over the rotating propeller surfaces was found to become more preferable along the radial direction with the formation of lobster-tail-like ice structures extruding out from the propeller blade surfaces. The aerodynamic performance of the propeller model was also found to degrade tremendously due to the ice accretion, causing a significant reduction (i.e., up to 70% reduction) in mean thrust generation and a dramatic increase in force fluctuation amplitude (i.e., up to 250% increase). Despite of different types of ice accretion, the propeller model was always found to consume more power operating under icing conditions (i.e., up to 250% more power consumption under glaze icing conditions).