The design and testing of helicopter rotor blade electro-thermal de-icing process model

Helicopter icing, especially the rotor icing, has long been a major field in aircraft icing research. The most commonly used strategy against rotor icing is the electrothermal deicing system, which periodically heats the already accreted intercycle ice and removes it. The basis of deicing heater design is analyzing the deicing process and the heater's performance. Generally, the study methods include icing tunnel experiment and numerical simulation. Due to the limitation of experiment conditions, experimental testing of deicing heater performance under icing conditions is not practical at present. In this paper, a 2D deicing process model has been developed via numerical simulation to investigate the melting performances of deicing heater, both while and after deicing heating process, and find out how to determine the power density. The numerical testing includes temperature distribution calculation, both in ice and in the heater itself; three varying parameters versus power density: the required heating time, energy consumption and surface temperature declining rate after heating process; the influence of ice thickness; uneven power requirement caused by the blade division; and deicing heater's performance under non-designed icing conditions. Testing results find out that, the required heating time declines with a declining rate when the power density increases; there is an appropriate power density for a dedicated deicing heater which leads to the minimum quantity of energy consumption per square meter and the fast declining rate of surface temperature after heating; ice thickness has little influence on the required heating time; and heating time should be adjusted according to detected icing parameters. This thesis is not designed for any specific helicopter, so the testing results give an insight, or a trend, of deicing heater's performance, rather than precise designed parameters. The research results provide some meaningful guidelines to analyze and design the deicing heater.