Elimination of Shock-Associated Noise in Supersonic Jets by Destructive Wave Interference
Artikel i vetenskaplig tidskrift, 2019

A novel application of fluidic injection was developed to investigate and understand the effects of discrete fluidic injection internal to the jet nozzle. Various injection locations, angles, and conditions were studied, resulting in unique acoustic behavior and flowfield modifications. For most conditions, the acoustics are relatively unaffected or increased, but for very specific conditions, noise was drastically decreased. For optimized conditions, the shock noise was completely eliminated, and in other cases, a jet instability was generated that significantly decreased high-frequency noise. Measurements of the velocity field indicated that shock interaction, due to shocks from the injection jets, interacts with the primary jet shocks and significantly reduces the shock strength, attributing massive shock noise reduction. Validation of the experimental results was achieved with large-eddy simulation, which provided additional insight into the shock suppression due to resolution of the flowfield internal to the nozzle. Optimal injection parameters resulted in reduction of overall sound pressure level of -7 d B at the upstream and downstream angles simultaneously through a combination of shock disruption and streamwise vorticity introduction. A new mechanism of supersonic jet noise reduction and destructive interference of the shock structure in the jet is reported.

Författare

Daniel Cuppoletti

US Air Force, Res Lab

Ephraim Gutmark

Univ Cincinnati, Aerosp Engn Dept, 799 Rhodes Hall, ML0070

Haukur Hafsteinsson

Chalmers, Mekanik och maritima vetenskaper, Strömningslära

Lars-Erik Eriksson

Chalmers, Mekanik och maritima vetenskaper, Strömningslära

AIAA Journal

0001-1452 (ISSN) 1533-385X (eISSN)

Vol. 57 2 720-734

Ämneskategorier

Rymd- och flygteknik

Farkostteknik

Strömningsmekanik och akustik

DOI

10.2514/1.J057402

Mer information

Senast uppdaterat

2019-08-18