Hostname: page-component-cd9895bd7-dk4vv Total loading time: 0 Render date: 2024-12-18T22:03:47.146Z Has data issue: false hasContentIssue false

Is the Weis-Fogh principle exploitable in turbomachinery?

Published online by Cambridge University Press:  19 April 2006

S. B. Furber
Affiliation:
Department of Engineering, University of Cambridge
J. E. Ffowcs Williams
Affiliation:
Department of Engineering, University of Cambridge

Abstract

Weis-Fogh discovered a remarkable new principle of aerodynamic lift. Hovering wasps exploit the principle and fly with an aerodynamic performance superior in some respects to anything previously known. In this paper we address the question of whether the Weis-Fogh effect can be exploited in turbomachinery. We think the answer is yes.

Normal turbomachinery design is based on the analysis of isolated cascades of blades with steady entry and exit flows. The interactions between adjacent cascades and nonuniformities of the flow are usually regarded as problems which have to be minimized. Unsteadiness gives rise to noise. In this paper we take the opposite view and examine a novel type of turbomachinery stage that depends on the interaction between rotor and stator for its normal operation. The stage exploits the Weis-Fogh principle and has the unusual property that when started from rest it generates a pressure rise without shedding any vorticity into the fluid. We argue that there may be a performance advantage for stages of this new type.

Experiments were done to check the validity of the theoretical model and these are described. The results seem to show that under certain circumstances a strong rotor-stator interaction can result in an improved stage performance, and we suggest that this improvement may be due to the Weis-Fogh effect.

Type
Research Article
Copyright
© 1979 Cambridge University Press

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

Abramowitz, M. & Stegun, I. A. 1964 Handbook of Mathematical Functions. Washington, National Bureau of Standards.
Batchelor, G. K. 1967 An Introduction to Fluid Dynamics. Cambridge University Press.
Coester, R. 1959 Theoretische und experimentelle Untersuchungen an Querstromgeblásen, vol. 28. Zürich: Leeman.
Horlock, J. H. 1958 Axial Flow Compressors. Butterworth Publications Ltd.
Jeffreys, H. & Jeffreys, B. S. 1956 Methods of Mathematical Physics. Cambridge University Press.
Kemp, N. H. & Sears, W. R. 1953 Aero. Sci. 20, 585597.
Lighthill, M. J. 1973 J. Fluid Mech. 60, 117.
Miller, D. C. 1971 The effect of axial gaps on compressor performance. Rolls-Royce Ltd. Int. publ. ref. no. G. N. 14229.
Weinig, F. 1935 Die Strömung um die Schaufeln von Turbomachinen. Leipzig: Joh Ambr. Barth.
Weis-fogh, T. 1973 J. Exp. Biol. 59, 169230.