rdf-syntax-grammar
mods:
  schema location: http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
  title info:
    title: Transient lift-off test results for an experimental hybrid bearing in air
  name:
    name part: Klooster, David.
    role:
      role term: creator
  name:
    name part: Childs, Dara W.
    role:
      role term: thesis advisor.
  type of resource: text
  genre: bibliography
  origin info:
    place:
      place term: txu
    date issued: 2011
    issuance: monographic
  language:
    language term: eng
  physical description:
    form: remote
    extent: 1 online resource.
  abstract: A hybrid bearing designed for use in a next generation turbo-pump is evaluated for the performance of initial lift-off, referred to as start-transient. The radial test rig features a high-speed spindle motor capable of 20,000 rpm that drives a 718 Inconel rotor attached via a high-speed coupling. The drive end is supported by ceramic ball bearings, while the hybrid bearing supports the opposite end. A magnetic bearing delivers the applied loading along the mid-span of the rotor. Many parameters, including ramp rate [rpm/s] (drive torque), supply pressure at 15,000 rpm, magnitude of the applied load, and load orientation, are varied to simulate different start-transient scenarios. The data are recorded in .dat files for future evaluation of transient predictions. Analysis of the data includes an evaluation of hydrodynamic and hydrostatic liftoff, an assessment of rub from passing through a lightly damped critical speed, and observation of pneumatic hammer instability. Hydrodynamic lift-off occurs when the hydrodynamic pressure, resulting from the relative motion of two surfaces, overcomes the forces acting on the rotor; no indication of hydrodynamic lift-off is provided. Hydrostatic lift-off results from the external supply pressure (which for this test rig is speed dependent) overcoming the forces acting on the rotor as determined from rotor centerline plots. With 0.263 bar applied unit load in the vertical direction, hydrostatic lift-off occurs at 0 rpm and 2.08 bar supply pressure. With a much higher load of 1.53 bar, hydrostatic lift-off is at 12,337 rpm and 10.7 bar supply pressure. The required supply pressure for hydrostatic lift-off is approximately a linear function of the applied unit load. In a turbopump, hydrostatic lift-off depends on the speed because the supply pressure is proportional to the speed squared. With the load in the horizontal direction, hydrostatic lift-off occurs at lower speeds and pressures. The ramp rate did not affect the required sup…
  note: by David Klooster.
  note: "Major Subject: Mechanical Engineering"
  note: Title from author supplied metadata (automated record created 2011-02-28 11:02:00).
  note: Electronic resource.
  note: Master of Science Texas A&M University 2009 http://hdl.handle.net/1969.1/ETD-TAMU-2009-12-7444
  note: Includes bibliographical references.
  note: Text (Thesis)
  subject:
    topic: Major mechanical engineering
  subject:
    topic: Lift-off
  subject:
    topic: Transient
  subject:
    topic: Hybrid Bearing
  identifier: http://hdl.handle.net/1969.1/ETD-TAMU-2009-12-7444
  record info:
    record content source: TXA
    record creation date: 110308
    record change date: 20151202115638.0
    record identifier: in00002654942