Hostname: page-component-cd9895bd7-jkksz Total loading time: 0 Render date: 2024-12-25T05:50:36.402Z Has data issue: false hasContentIssue false

The prevention of separation and flow reversal in the corners of compressor blade cascades

Published online by Cambridge University Press:  04 July 2016

B. S. Stratford*
Affiliation:
Rolls-Royce (1971) Ltd.

Summary

From tests on tunnel cascades one of the sources of loss in axial compressors could be corner stall, i.e. local separation of the flow in and near the corners between the annulus walls and the convex surfaces of the blades.

Tests on a tunnel cascade at entry Mach numbers of 0·5 and 0·6 show that, at least in a tunnel, the stalling may be cured by boundary layer control. The present tests obtain control by suction through a corner slot. The tests show that removal through the slot of 1·3% of the flow decreases the total losses of the cascade by about 25%.

A more detailed examination of the losses in the tunnel cascade without suction suggests that about three-quarters of the end losses are due to the separation and reverse flow. Much of the remaining end loss appears to result from the fact that the low energy stream tubes in the entry boundary layer would experience a disproportionately large increase in cross-sectional area during diffusion, even in attached two-dimensional flow. The suction corner control can eliminate the greater part of the end losses, by eliminating the separation.

Type
Technical notes
Copyright
Copyright © Royal Aeronautical Society 1973 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Howell, A. R. Fluid Dynamics of Axial Compressors. Proc Inst Mech Eng, Vol 153, pp 441452, 1945.Google Scholar
2. Griffith, A. A. Discussions at Rolls-Royce, 1948.Google Scholar
3. Malley, H. H. Application of boundary layer control at the ends of aerofoils in cascade. Unpublished work at Rolls-Royce, 8th February 1949.Google Scholar
4. Louis, J. F. Stalling phenomena in axial flow com pressors. PhD thesis, Cambridge University, 1957. See also: Rotational viscous flow, Int Congress of Applied Mechanics, communication I 244, 1956, and R&M 3136, 1958.Google Scholar
5. Peacock, R. E. Boundary layer suction to eliminate corner separation in cascades of aerofoils. R&M to be published.Google Scholar
6. Stratford, B.S. An experimental flow with zero skin friction throughout its region of pressure rise.JFM, Vol 5. Pt 1, pp 1735, 1959.Google Scholar
7. Stratford, B.S. The prediction of separation of the turbulent boundary layer. JFM, Vol 5 Pt 1, pp 116, 1959.Google Scholar