Published online by Cambridge University Press: 28 July 2016
The contraction of a wind tunnel should be free from adverse pressure gradients, since this might cause boundary layer separation.
A wall contour has been designed for a circular cross-section contraction using incompressible flow theory. This gave a favourable pressure gradient at the beginning of the contraction where separation is likely to occur.
Appendix I compares the theory with experimental results obtained from a model of a proposed supersonic tunnel of which the contraction is rectangular in cross-section and which has been based on the results obtained in this report.