Investigation of the Impact of a Particle Foam Insulation on Airflow, Temperature Distribution, Pressure Profile and Frost Buildup on the Aircraft Structure

Aircraft insulation separates the thermally comfortable cabin interior environment from the extremely cold outside conditions. However, the fabrication and installation of the insulation in the aircraft is a labor-intensive task. Tailored, rigid particle foam parts could be a solution to speed up the installation process. The presented study investigates the feasibility of such a concept from a hygrothermal point of view. Due to the temperature difference between the cold air trapped between aircraft skin and insulation on one side and the warm cabin air on the other side, a buoyancy-induced pressure difference forms. This effect drives the warmer air through leakages in the insulation system towards the cold skin. Here, moisture contained in the air condenses on the cold surfaces, increasing the risk for uncontrolled dripping (“rain in the plane”) when it melts. Therefore, this study compares the condensate build-up of different installations of a rigid particle foam frame insulation with the classical glass fiber capstrip. Tests are hosted in the Fraunhofer Lining and Insulation Test Environment chamber. It is shown that careful installation of the particle foam frame insulation provides similar level of moisture protection as the current state of the art insulation, and that the condensate amount does not depend on the amount of airflow directly behind the sidewall.