Study on the insulation characteristics of the pack outlet muffler duct of a civil aircraft

A civil aircraft added a muffler section to its cooling pack outlet duct, which increases the heat transfer area between the duct and the outside atmosphere, making it necessary to recalibrate the insulation characteristics of the muffler duct. In this pa per, the flow field and temperature field characteristics of the duct are investigated using CFD methods, and the effects of the d uct inlet temperature and the thickness of the insulation on the insulation characteristics of the duct are also investigated. Th e results of the study show that the increase in the heat exchange area of the duct muffler section significantly reduces the insulation effect of the muffler section. And the presence of the insulation layer has a significant impact on the insulation effect of the duct, while there is little correlation between duct insulation effectiveness and duct inlet air temperature.