In order to research the dynamic response of the high bypass ratio turbofan engine under fan blade off

and finish the safety design better

the sudden unbalance experimental system with fan blade off device based on similarity theory were designed and experimental verification was finished. Research shows that the sudden unbalance experimental system has high similarity to some demonstration engines

which can finish the sudden unbalance experiment with good repeatability

clear mechanism and big unbalance

furthermore

it can simulate the fan blade off of the engine really. Through the experiment

it was found that when the large sudden unbalance occurred

the superharmonic frequency spectrum appeared and the impact coefficient didn’t show a linear relationship due to the limiting effect of the squeezed film damper

so the rubbing problem caused by the limiting should be concerned in the subsequent research.