Performance Investigation On Anti-icer Of Composite Engine Inlet Vane

When aircraft fly under icing condition, the impingement of super-cooled droplets in the cloudson the exposed surfaces of aircraft may cause ice accretion. Accreted ice on the aircraft has severelyadverse effects on flight safety, like changing the aerodynamic shape of aircraft and causing errors tothe sensors, and has been one of the main reasons of aircraft disasters. Anti-icing or de-icing systemmust be equipped to ensure flying safety. Efforts have been made on the research of theory of aircrafticing and methods of de-icing and anti-icing.Composite has been widely used on modern aircraft. Though many differences betweencomposite and metal meterails, there lacks research of composite assembly anti-icing and de-icingsystem where potential damage exists. To evaluate composite engine inlet vane anti-icing system,icing wind tunnel experiments and numerical simulation were carried out in this paper.The followings are the the main works in this thesis:1) The cause, hazards of aircraft icing andmethods of protection and the application of composite on aircraft were introduced, the ways ofinvestigation and the state-of-art of icing and anti-,de-cing, and the necessity of research of anti-icingof composite assembly were summarized.2) A small open-circuit icing wind tunnel based on highpressure air source was built, in which the air source is the air compressor sets and the refrigerantsystem is a combination of Freon refrigerator and air turbines. The spray systems were consisted ofair/fluid nozzles. The measurement of the icing condition parameters of the icing wind tunnel wasdiscussed. The running tests of impingment and icing were carried out and the results were vadidatedby numecial simulation.3) Electro-thermal anti-icing structure on a composite engine inlet vane wasdesigned. Anti-icing experiments of the structure were run in the small open-circuit icing wind tunnel.Single zone heating tests were carried out to evaluate the influence of flying and meteorologicconditions and different anti-icing modes. Two-zones heating tests were carried out and comparedwith single zones heating tests to evaluate the influence of heating methods to the temperaturedistribution of vane. Impingement characters of engine inlet vane under small icing wind tunnelcondition were calculated and the influence of flying and meteorologic condition was analized; theanti-icing thermal load under test conditions was calculated. Electro-thermal anti-icing of compositeengine inlet vane under tests conditions was numerical simulated. The results were validated bycompare with the experiment results and indicate the capability of the design of electro-thermalanti-icing system under real engine condition.4) A new hot-air anti-icing structure of composite engine inlet vane was developed after the analysis of original system by numerical simulation of itsinner flow and heat transfer and super-cooled droplets impingement microchannels and jets were usedto enhance the heat transfer characteristics of leading edge.A narrow gap was opened and assigned onthe vane surface at the rear end of the anti-icing tunnels, and the exhaust hot-air was released from thegap to form an air film on the outside surface, which was supposed to prevent the droplets fromimpinging to the surface and sweep the droplets and running back water away. The thermodynamicanalysis of the original and newly developed anti-icing structure was presented to compare the effectsto heat transfer and droplet impingment.5) Experiments of the developed hot-air anti-icing structurewere run in the icing wind tunnel to evaluate the effects of microchannels and jets to anti-icing, andair film to sweep the running back water.6) The work in this theis was summarized and some newideas were presented...