A jet exhausting over a plate at different distances away from the nozzle was investigated to
simulate jets exhausting over airframe surfaces and the jet-ground interaction during take-off …

An image analysis method is developed and applied to shadowgraph images of supersonic
jet flow to measure shock front propagation angles at numerous interrogation points …

Spatial properties of noise statistics near unheated, laboratory-scale supersonic jets yield
insights into source characteristics and near-field shock formation. Primary findings are (1) …

The noise produced by supersonic, high temperature jets that exhaust from military aircraft is
becoming more of a disturbance. Methods to reduce the noise produced from these jets in a …

Crackle is a perceptual feature of supersonic jet noise that is related to the presence of
acoustic shocks. This study investigates the apparent source locations of the steepest …

In this paper, quantitative understanding of a frequency-domain nonlinearity indicator is
developed. The indicator is derived from an ensemble-averaged, frequency-domain version …

This paper describes several components of a study examining noise reduction in high
speed heated jets using fluidic inserts. This noise reduction technology is based on the …

The turbulence generated in supersonic, high-speed jet flows is responsible for the
dominant noise associated with high-performance military engines. Supersonic jet noise can …

Ffowcs Williams et al were the first to discover crackle in the noise of the Concorde when the
Olympus 593 engine which propelled Concorde was operating at afterburner power. Ffowcs …

This paper examines the spatial origin of events that relate to the development of crackle.
Crackle is an annoying1 and dominant2 component of supersonic jet noise. Ffowcs Williams …