Propulsive jets and their acoustics.

Summary of "Acoustics of Supersonic Jets: Launch Vehicle and Military Jet Acoustics"

Swimming dynamics and propulsive efficiency of squids throughout ontogeny.

Squids encounter vastly different flow regimes throughout ontogeny as they undergo critical morphological changes to their two locomotive systems: the fins and jet. Squid hatchlings (paralarvae) operate at low and intermediate Reynolds numbers (Re) and typically have rounded bodies, small fins, and relatively large funnel apertures, whereas juveniles and adults operate at higher Re and generall...

Input - output analysis of high - speed jet noise

We use input-output analysis to examine subsonic and supersonic turbulent jet noise. For a supersonic jet, the leading input-output mode closely resembles wavepackets resulting from the parabolized stability equations (PSE). For a subsonic jet, however, input-output analysis produces several sub-optimal modes with nearly the same gain as the leading input-output mode. The sub-optimal modes depe...

Mean Flow and Acoustics of Dual - Stream Jets

This study examines the connection between the mean ow shape and the acoustic emission of dual-stream jets. The experimental investigation encompassed jets issuing from coaxial, eccentric, and arcuate nozzles, as well as nozzles with de ectors in the secondary stream. The in ection points of the transverse velocity pro le were used to de ne the generalized secondary core (GSC) of the jet. In co...

Global Artificial Boundary Conditions for Computation of External Flow Problems with Propulsive Jets

We propose new global artificial boundary conditions (ABC’s) for computation of flows with propulsive jets. The algorithm is based on application of the difference potentials method (DPM). Previously, similar boundary conditions have been implemented for calculation of external compressible viscous flows around finite bodies. The proposed modification substantially extends the applicability ran...