Some shrouding and tip clearance effects in axial flow compressors¹

Article type: Research Article

Authors: Jefferson, J.L. | Turner, R.C.

Note: [1] Paper read before the North Fast Coast Institution on February 7, 1958.

Abstract: The paper, with a reference to the economics of blade manufacture, explains the reasons for the main series of tests, which were carried out at the National Gas Turbine Establishment, the material being supplied by C.A. Parsons and Company, Limited. Four series of tests are described in detail. Various combinations of shrouding and tip clearance were investigated, untwisted constant-section blading being used in the first three series. The experiments were carried out over a range of shrouding leakage clearances, and also included an investigation of the boundary layer flow on the convex surface of a stator blade in the compressor. A brief review of published work on the effects of normal radial tip clearance is followed by a description of some early results obtained on a multi-stage compressor. It is concluded that shrouding of the type investigated should, if possible, be avoided, especially under certain aerodynamic conditions. If it is necessary that it be used, the clearance should be maintained at the smallest practicable value. The use of very fine radial tip clearances may also result in a loss of performance, although values in excess of 1 per cent. of the blade height are also shown to be undesirable in the particular case investigated.

DOI: 10.3233/ISP-1958-54203

Journal: International Shipbuilding Progress, vol. 5, no. 42, pp. 78-101, 1958