![]() They can be either homogeneous or fibre-reinforced, being produced by extrusion or injection techniques, and further combined with coating layers to reduce friction between mating components. It is up to the seal manufacturers to define complex seal profiles made of several different thermally stable elastomers, that are suitable for the sealing interface. In an aircraft development, door seals are defined according to the main structural and kinematic elements of the fuselage and the door mechanisms. For this reason, the relations between seal, striker and cabin pressure are a piece of crucial information to design an efficient interface. In such conditions, the leakage of air is triggered, which can later be traced as a source of aerodynamic noise, vibration and, in critical scenarios, cabin depressurisation. Since the seal profiles are inserted into the specified radii and door contours, some points can arise where the sealing line is no longer locally stable, which also affects the contact pressures and thus the final sealing effect. In an ideal door system, the contact stress distribution between the seal and the striker interface should be as independent as possible from all external disturbances. Predicting the risks of air leakage under cabin differential pressure is essential to guarantee the seal functionality. In its attempt to return to the initial configuration, an elastomeric seal can reach the sealing effect, if the contact pressures remain higher than the fluid pressure over the contact boundaries. The hyperelastic behaviour and the nearly incompressible nature of rubber play an essential role in sealing performance. Elastomers have been primarily employed for seal door systems due to their intrinsic ability to take shape from their mating interface when subjected to large deformations. ![]() ![]() Inflatable design solutions are generally employed since they take advantage of the positive pressure by adding vent holes to increase the contact forces with the mating interface. In order to keep the air pressure for breathable human conditions, elastomeric seals solutions are added to the aircraft doors to avoid air leakage.įigure 1 illustrates how the cabin differential pressure load is ideally distributed over the seal cross section and the surrounding door structures. Around the contours of aircraft doors, gaps are necessary to accommodate the kinematics of the opening and closure mechanisms. During an aircraft flight, the pressure difference between the cabin and the outer atmosphere generates distributed loads which need to be withstood by the fuselage and the cutout structures. ![]()
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