Reduced fan containment threat through liner and blade design

1. A blade containment system comprising:

a plurality of circumferentially-arranged rotatable blades, each blade having a blade compliance; and

an annular containment structure radially outward from the rotatable blades, the annular containment structure including a liner having a liner compliance, the blade compliance and the liner compliance being configured such that a strain induced on a respective one of the rotatable blades upon impact with the liner is less than a threshold critical strain beyond which the rotatable blades fracture, wherein the liner includes an inner liner and an outer liner, the inner liner being composed of an adbradable layer and a honeycomb, a hollow cavity located radially between the honeycomb and the outer liner, a purge channel connecting to the hollow cavity and a vent configured to selectively ventilate a gas from the hollow cavity, wherein the vent includes a plurality of vent openings and is located downstream of the rotatable blades, the purge channel extending adjacent another, downstream honeycomb, and at least a portion of the plurality of vent openings are radially inwards of the downstream honeycomb.

2. The system as recited in claim 1 , wherein each of the rotatable blades includes an interior cavity.

3. The system as recited in claim 2 , wherein the interior cavity is elongated along a chord-direction of each of the rotatable blades.

4. The system as recited in claim 2 , wherein the rotatable blades are made of aluminum alloy.

5. The system as recited in claim 1 , wherein the inner liner is a modular cartridge.

6. The system as recited in claim 1 , wherein the downstream honeycomb includes intercellular slots that connect adjacent cells of the downstream honeycomb to the plurality of vent openings.

7. The system as recited in claim 6 , wherein a portion of the plurality of vent openings open radially outwards.