Study On Aircraft Cabin Bleeding Air Pollution Based On AMESim And FLUENT Coupling Simulation

The aircraft environmental control system(ECS)is the vital subsystem of aircraft,which provides appropriate pressure,temperature and humidity for the crew members and passengers.While the pressure cabin is a particular carrier maintaining the target pressure,temperature and humidity parameters within a proper range.Thus ECS and cabin are the integrate systems.Simply,the bleed air from engines passes through the ECS,where the temperature and humidity can be regulated,then the justified air get into cabin,but a part of the exhausted air from cabin reentry the cabin through ECS.These two different systems affect each other observablyFor the mechanical failures,maintenance errors and design faults,the engine lubricating oils,hydraulic fluids,or their pyrolyzed products may enter the ECS and contaminate the cabin air.But current research can not figure out how the contaminants from the ECS reach to cabin,and how the exhausted air from cabin affects the ventilation air.Usually,one dimensional simulation method can accurately model the environmental control system and get every single change of the units' parameters,but can't get the detailed flow field information and pollutant diffusion model.While the computational fluid dynamics(CFD)software can capture very detailed fluid results in cabin,a precise modeling of the ECS part is hard to build.This paper investigates the bleed-air contaminant from the ECS to cabin and shows the inter-affects within two systems on different recirculating air ratio and air supply mode,which based on the coupled simulation method between one dimensional simulation software and CFD software.The results show: 1.The pollutant diffusion in cabin is totally different with recirculating air and without recirculating air.2.In different air supply mode,contaminants spreading in cabin and eliminating from cabin are also distinctive.3.The mixing ventilation and sidewall ventilation are superior to the ceiling ventilation considering about the breathing zone of passengers.