Failure Mode Analysis of High-Pressure Duct Bleed Air Leakage

High-pressure ducts for civil aircraft Environmental Control Systems bleed air to the aircraft and regulate the temperature of the cabins to ensure ventilation and thermal comfort in the cabin. high-pressure duct air leakage is a typical of Particular Risk Analysis (PRA) candidate item, where the failure effects of a high-pressure duct leakage can be determined by 3D modelling simulations and experimental verification. However, as there are may more than hundreds of leak points on the high-pressure duct,3D modelling and experimental validation are typically cost high and consume several months. Therefore, this paper proposes a method to calculate the failure impact area based on the cone flow field characteristics and temperature distribution of the high temperature and high-pressure air leak out of the high-pressure duct, which is similar to the non-isothermal jet formed at the breakage of the duct, i.e. the leak point, in order to improve the efficiency of PRA, help to screen out the leak points at the early stage of design that are necessary to carry out 3D simulation and experimental verification, and can provide data to support airworthiness verification. At the same time, the proposal analysis method help to identify the leakage zone and its temperature and flow field distribution, which can be used as a reference and basis for the installation of the high-pressure duct and surrounding systems, and the structural design of the airframe.