헬리콥터 로터 블레이드 제빙시스템 설계를 위한 블레이드 제빙해석 기법 연구

When the helicopter is flighting through icing condition, the ice could be accreted on fuselage and blades. The ice on blade could deform the blade configuration and increase the weight of blade. The unstable motions of blade make decreasing of performance, handling quality and structural stability due to the abnormal weight increase and configuration change. The helicopter deicing system is required to avoid risk by icing. Generally, the engine intake and the pitot sensor are adapted anti-icing system, but the rotor blade uses deicing system because the large size heater mat of blade needs a lot of power consumption. The anti-icing system is always active heater mat in icing condition; the deicing system is run alternately by on/off time sequence to avoid ice accretion on blade. Especially, due to the composite blade is weak by heat, over heat could make weak brittleness of blade. Thus, the de-icing system should be designed not only eliminate the ice on leading edge but also not damage the blade by heat source. First of all, the icing region estimation on blade is needed to design of rotor blade deicing system. In this paper, air flow field and multi-phase fluid analysis was performed by the commercial CFD s/w, SC/Tetra to calculate the collection efficiency around objects. The ice accretion analysis was performed by developed in-house code, ASTROD based on Messinger thermodynamic model. The computation result shows good estimations of icing region and ice thickness. In this study, de-icing situation is simplified that the blade surface adjoin with ice and thermal conduction occur at that interface. To analysis of convection on exterior surface of ice and internal heat power from heater mat by numerical method, discrete computational nodes of ice covered blade and consider phase change at the interface blade and ice. The numerical analysis result compared with ice wind tunnel test data of the blade to evaluate. The numerical method results show similar with experimental data about time to eliminate the ice and temperature of off-time range.