Correlation in the random pressure field close to a jet

Abstract

A recent suggestion in an earlier report by the authors that a relationship exists between the auto-correlation of the fluctuating pressure near to a jet and the space-correlation along lines parallel to the boundary of the jet is examined and confirmed. The ideas involved are used to account for the fact that the longitudinal space-correlation curve is independent of jet speed, and this is illustrated by a simple calculation and an experiment. The explanation is then expanded to demonstrate the possibility of similarity between model and full-size experiments, and this possibility is confirmed by a comparison of the present work with similar full-scale work carried out at the Royal Aircraft Establishment.