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Studies on Thwaites’ method for wind tunnel contraction

Published online by Cambridge University Press:  04 July 2016

E. G. Tulapurkara*
Affiliation:
Department of Aeronautical Engineering, Indian Institute of Technology, Madras

Extract

Nearly 15 methods have been proposed to obtain the shape of an axisymmetric wind tunnel contraction, but only a few have been studied experimentally. Bibliographic details of these methods can be found in Refs. 1, 2 and 3. Of these, the method described by Thwaites has the advantage that the contour and the velocity distributions are given directly by simple series expression. This method also has the criticism that the solution is periodic and does not satisfy near uniform stream condition obtained at inlet and outlet. But such a criticism applies to all methods which assume the length of contraction to be finite (e.g. methods due to Batchelor and Shaw, Chmielewski. Further, an experimental investigation by Klein et al(3) showed that Thwaites’ method with first four terms in solution gave a better performance than the contour given by Batchelor and Shaw.

Type
Technical Notes
Copyright
Copyright © Royal Aeronautical Society 1980 

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References

1. Chmielewski, G. R. Boundary layer considerations in the design of aerodynamic contractions. Journal of Aircraft, Vol 11, pp 435438, 1974.Google Scholar
2. Morel, T. Comprehensive design of axisymmetric wind tunnel contractions. Journal of Fluid Engineering, Vol 97, pp 225233, 1975.Google Scholar
3. Klein, A., Ramjee, V. and Venkataramani, K. S. An experimental study of subsonic flow in axisymmetric contractions. ZFW, Vol 21, pp 312320, 1973.Google Scholar
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6. Batchelor, G. K. and Shaw, F. S. A consideration of the design of wind tunnel contractions. Australian Council for Aeronautics Report ACA-4. 1944.Google Scholar
7. Tulapurkara, E. G. Theoretical study of Thwaites' method for wind tunnel contractions using large number of terms. Indian Institute of Technology, Madras, Report AE-TN-1, 1976.Google Scholar
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