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.

  • Corporate Authors:

    University of Oklahoma, Norman

    School of Aerospace, Mechanical and Nuclear Engineering
    Norman, OK  United States  73069

    Department of Energy

    1000 Independence Avenue, SW
    Washington, DC  United States  20585
  • Publication Date: 1978-11

Media Info

  • Pagination: 122 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00198135
  • Record Type: Publication
  • Source Agency: National Technical Information Service
  • Contract Numbers: EY-76-C-04-0789
  • Files: TRIS
  • Created Date: Dec 29 1979 12:00AM