Mechanism Study On Heat Transfer And Flow Of Hot Air Anti-Icing For Guide Vane

Ice accretions may occur on certain exposed parts of an airplane, such as the windscreen, the aerofoil, and the tail when the airplane flies in clouds which contain super-cooled water droplets. This is very dangerous since ice accretions can seriously degrade aircraft performance and handling characteristics. Similar problem also exists on aircraft engines. For turbo-shaft engine, ice accumulated on the inlet guide vane of the engine can worsen air ingestion. In addition, shed ice may be sucked into the engine and induces serious damage. In order to reduce the hazards caused by in-flight icing, most modern airplanes have been equipped with anti-icing systems.This thesis investigates a widely used hot air anti-icing system and makes improvement of current computation model in order to get better results, trying to find a simple and effective method to evaluate its performance. The work is carried out in simulating air intake pipelines of the hot air anti-icing system, presenting a numerical method for calculating the water droplet impingement efficient, improving the thermal balance analysis model, developing a program for calculating the surface temperature. First, the current thermal balance model is improved by introducing a factor—wetness factor F. Then the guide vane is modeled, fluid field around the guide vane is also analyzed, followed by a program for calculating surface temperature is developed. At the end, the results are analyzed and compared with those based on the former model. In conclusion, it is found that the surface temperature is higher than that based on the previous way, which means the previous way is a waste of hot air. According to the new results, less hot air is needed, which will significantly improve the engine performance. The heat transfer from the kinetic energy of the droplets can be ignored because it just takes a small count of the total by comparing the percent of different heat flux.