A new anti-icing method for an aero-engine nose cone

Ice accretion may occur on the entry components of an aero-engine under certain weather and flight conditions, which would lead to the deterioration of the engine performance and even severe safety problems. Anti-icing systems have been used including hot air anti-icing system, which consumes high pressure air from the compressor, and electronic heating system, which consumes high grade electronic energy. Compared with the traditional anti-icing methods, an efficient and low energy consumption anti-icing technique based on the rotating heat pipe (RHP) has a great advantage and good application potential, which utilizes the waste heat of the aero-engine. Until now, however, the mechanism of the heat transfer in a RHP has not been clearly revealed yet, due to the complexity of the two phase flow and phase change process occurred in the RHP, which makes it difficult to establish the design method for the aero-engine anti-icing system based on a RHP. Furthermore, the feasibility of the anti-icing system based on a RHP has not been confirmed by experiments. Therefore, the present work is focused on the theoretical and experimental investigations on the rotating nose cone anti-icing technique based on a RHP, in order to explore the two phase flow and heat transfer mechanism of such an anti-icing system, and to reveal the effects of different parameters on the performance of the system, which may provide the theory basis for the design of the nose cone anti-icing system based on a RHP. Furthermore, it is expected that the feasibility of the anti-icing system based on a RHP can be confirmed by the experiments on a prototype, providing the basis for the engineering applications. In this study, a nose cone anti-icing structure based on a RHP has been proposed, and the mathematical model based on the complete Navier-Stokes equations was established to explore the details of fluid flow and heat transfer in the anti-icing system. The volume of the fluid (VOF) model was employed for the simulation of two phase flow, and a new phase-change model was introduced to predict the evaporation and condensation processes in the RHP while the balance between the evaporative and condensing masses was considered. Numerical simulations have been carried out to study the operation characteristics of the system. The impact of parameters such as the rotational speed, the heat transfer rate, heat conductivity of the filler and heat transfer coefficient between the heat pipe and heat source on the performance of the anti-icing system have been examined. A prototype of the nose cone anti-icing system based on a RHP has been developed for the ice wind tunnel tests. The results indicated that the anti-icing system has the ability to maintain the temperature of the nose cone above the freeze point under certain conditions. It is found that the theoretical model can be used to predict the performance of the nose cone anti-icing system based on a RHP, and the prototype has a satisfactory anti-icing performance. The investigations laid a solid foundation for the engineering applications of the anti-icing technique based on RHPs.