Whirling response and stability of flexibly mounted, ring-type flywheel systems

Technical Report · Wed Nov 01 04:00:00 EST 1978

OSTI ID:6432309

Chen, T L.C.; Bert, C W

The scarcity and rising cost of petroleum have motivated international interest in developing hybrid automobiles using flywheels for mechanical energy storage. Rim-type composite-material flywheels are promising designs for such developments. These flywheels significantly differ from turbine/compressor systems in two respects. First, the flywheel rim attachment to its hub is very flexible, for both translation and tilting. Secondly, these flexibilities depend upon rotational speed through centrifugal stiffening. Free whirling, stability, and forced whirling are examined for these flywheel systems. The numerical results are most directly applicable to the Sandia single-rim systems currently under development. However, the analyses can be extended to other flywheel designs within the broad category of the rim type. In the free-whirling analysis, predicted critical speeds are encountered in the design operating speed range. Practical ways to increase such critical speeds are suggested. Effects of material internal damping on the stability of the system are incorporated through adopting complex moduli in the formulation. It is found that the adverse effect of internal damping on the onset of instability can be overcome by providing an adequate external damper up to a considerably high speed. Forced whirling excited by unbalance and initial tilt of rim element is studied. Minimum external damping is determined such that the maximum response does not exceed a permissible value.

• Research Organization: Oklahoma Univ., Norman (USA). School of Aerospace, Mechanical and Nuclear Engineering
• DOE Contract Number: EY-76-C-04-0789
• OSTI ID: 6432309
• Report Number(s): SAND-78-7073
• Country of Publication: United States
• Language: English

Related Subjects

25 ENERGY STORAGE
250500* -- Energy Storage-- Flywheels
33 ADVANCED PROPULSION SYSTEMS
330400 -- Advanced Propulsion Systems-- Hybrid Systems
COMPOSITE MATERIALS
DAMPING
ELECTRIC-POWERED VEHICLES
FLYWHEELS
HYBRID ELECTRIC-POWERED VEHICLES
MECHANICAL ENERGY STORAGE EQUIPMENT
MECHANICAL VIBRATIONS
STABILITY
VEHICLES