This paper investigated the variation of dynamical response of a low pressure rotor in turboshaft engine with its system parameters.Based on the model of low pressure rotor

a dynamical simplified model of two-disk rotor with squeeze film damper at each end was built.Its motion equations were derived.The numerical method was applied to solve the 12-dimensions differential equations.The influence of some parameters

e.g.

rotating speed

eccentricity and its phase angle

mass ratio of two disks

were analyzed.From simulation results

it can be seen that when phase difference of two disks' eccentricity is π

the two disks have their minimum vibration amplitude respectively.When their phase is identical

their vibration responses reach maximum values.The larger the mass of mid-span disk is

the larger the vibrations of two disks are.When mass of mid-span is lesser than that of overhung rotor

the response of system will decrease.