The representation of engine airflow in wind-tunnel model testing

Abstract

The problems of engine airflow representation in wind-tunnel models are reviewed. Methods which have been used satisfactorily in low subsonic tunnels are described briefly. Special difficulties associated with testing at transonic speeds are noted. Techniques of special application to small supersonic tunnels are described in some detail. It is shown that there are reasons why the representation of jets may be more important at supersonic speeds than at subsonic speeds and a description is given of the Royal Aircraft Establishment Jet Interference Tunnel, which is designed for the study of some of the problems involved.