DYNAMIC MEASUREMENT OF BLADE VIBRATION AT THE LAST LOW PRESSURE STAGE OF AN ACTUAL MARINE TURBINE

With progress in theoretical approach techniques to problems on blade vibration of marine propulsion steam turbines, an accurate calculation of the natural frequencies of banded blade groups has now become possible. Based on the assumption of fixed conditions, the calculation has now reached the stage where resonant vibration stress can be calculated inasmuch as the magnitude of stimulus and damping are known. In order to investigate these factors, a dynamic measurement of vibration was performed by means of a telemetering system at that last low pressure stage blade of an actual 29,000 PS marine turbine during sea trials. As a result of the various preliminary confirmation tests performed on the strain gages, transmitters, and batteries, which were exposed to high temperatures and high centrifugal forces under operating conditions, prior to their installation on the turbine rotor, the test apparatus operated normally during the sea trials. The analytical results of the data measured showed the logarithmic decrement of damping for the last low pressure stage banded blade group to be approx. 0.01 and the fractional value of stimulus for 4-6th harmonic order resonance to be approx. 0.01.

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  • Corporate Authors:

    Ishikawajima-Harima Heavy Industries Co., Ltd.

    2-16, Toyosu 3 Chome, Koto-Ku
    Tokyo 135,   Japan 
  • Authors:
    • Ohkuwa, T
    • Ohba, M
    • Nakasu, K
    • Tanaka, K
  • Publication Date: 1975-1

Media Info

  • Features: References;
  • Pagination: p. 23-34
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00095349
  • Record Type: Publication
  • Source Agency: Ishikawajima-Harima Heavy Industries Co., Ltd.
  • Files: TRIS
  • Created Date: May 29 1975 12:00AM