Simulation And Performance Study Of A New Bleed Air Filter Of Aircraft Environmental Control System

During the various environmental conditions in the flight, the air usually contains dust particles. For purpose of avoiding the damage to the core component-the turbine rotor of the refrigeration system, the bleed air needs to be filtered. Based on the requirements of the bleed air filter in the aircraft environmental control system, a new type of bleed air filter unit without the screen filtration was developed in this paper to replace the traditional mesh filter, and using the numerical simulation to study the operating principle of bleed air filter and the analysis of the influence factors of filter performance.The main research object was the bleed air filter of Environment Control System in a high temperature and high pressure environment, the main research work was divided into the following four parts: firstly, according to the requirements of collection efficiency of bleed air filter in the Environmental Control System and pipe installation, the basic size of bleed air filter was determined by the reference general cyclone design method, using split type guide vane to fulfill the design of the guide vane, so the initial structure was designed. Secondly, on the basis of the theory and the numerical simulation analysis, the difference of the Realizable k ?? model and the Reynolds Stress Model was compared for the filter. Meanwhile the internal pressure distribution and velocity distribution characteristics of the bleed air filter, also and the impact on the dust removal efficiency and pressure drop were analyzed under the two turbulence models. Based on the numerical simulation method, the characteristics of the flow field and particle phase were calculated in the gas-solid flow for analyzing the dust removal mechanism of the filter. Finally, based on the numerical simulation method, the influence to the performance of bleed air filter because of the geometric parameters, such as blade twist angle, the vane channel, separation space, the collection chamber and the flow parameters, for example the flow of inlet, the size and density of the particle, the concentration of inlet were researched. The basic design principles of bleed air filter without filter screen in the aircraft environmental control system were summed up with modifying the design method of the pressure drop and also with the influence law of various parameters on the filter performance by the results of numerical simulation.