Turbomachine casing comprising a device preventing instability in the event of contact between the casing and the rotor

摘要

The casing (110) has an anti-instability device (120) provided on an inner surface of the casing for preventing instability during a contact between the casing and an impeller e.g. one-piece blade disc. The device has two types of elements (122, 124) placed along a circumference of the casing and presents different rigidity between the elements, where the two types of the elements are formed of two different abradable material layers of different Young's modulus. Number of elements of same rigidity is different from multiple of wave number of vibration mode of the impeller. An independent claim is also included for a method for preventing an occurrence of instability during a contact in a stator/rotor assembly of a turbo machine.