An experimental technique to predict the onset of aeroelastic flutter of an
enclosed computer memory disk is presented. The aerodynamic pressure is mo
delled as the sum of dissipative and circulatory linear operators, which su
bsumes as a special case the pressure generated in a thin hydrodynamic film
between the disk and the wall. It is shown that the aeroelastic model para
meters can be extracted from the frequency response function of the disk sp
inning at subcritical speeds. The aeroelastic parameters for an acousticall
y excited single disk at different enclosure gaps are derived for the speed
range 6,000-19,800 rpm. The flutter speed predicted is strongly influenced
by the enclosure gap and the substrate damping. A Butter speed as low as 3
5,000 rpm has been predicted. The technique can also be extended to predict
the Butter speed in other systems including DVD and CDROM drives. (C) 2000
Academic Press.