As power plants are increasing in capacity, rotating blades used in the last stage of low-pressure turbines are becoming larger and more flexible and their vibration characteristics more complicated. In designing long blades, much consideration has been paid to the prevention of resonance in lower mode vibrations and also to provide them with sufficient mechanical strength to be able to withstand resonance in higher mode vibrations. However, the increase of their sizes in recent years is now compelling manufacturers to conduct stricter analysis of their vibration phenomena. The authors investigated the vibration characteristics of last stage rotating blades as group blade by the analytical procedure based on the beam theory and found out the following: 1) The theoretical value of the natural frequency of the turbine blade shows a good agreement with the experimental value for higher mode vibrations as well as lower mode vibrations. 2) For the prevention of resonance it is effective to adjust the number of blades, the position of lashing wire and the thickness of the disc. 3) The theoretical value of their response characteristics against harmonics shows a good agreement with experimental values and resonance amplitude can be estimated with a considerable dependability.

  • Corporate Authors:

    Mitsubishi Heavy Industries Limited

    2-5-1, Marunouchi, Chiyokaku
    Tokyo,   Japan 
  • Authors:
    • Shiraki, K
  • Publication Date: 1972

Media Info

  • Pagination: p. 1-8
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00084489
  • Record Type: Publication
  • Source Agency: Japan Shipbuilding Industry Foundation Library
  • Files: TRIS
  • Created Date: May 7 1975 12:00AM