Flow and far field acoustic amplification properties of heated and unheated jetsThe interaction of an acoustic pulse with the experimentally determined mean flow field of a spreading jet is simulated numerically. The simulation is obtained through solving the Euler equations linearized about the spreading jet. The model reveals a small, sustained oscillation long after the original pulse has passed. This remnant is considered a continual shedding of vortices from the nozzle lip, together with the generation of acoustic ripples. IT is shown that the jet also acts as an amplifier of sound. This amplification is traced to the jet's stability characteristics. It is demonstrated that some of the observed differences in the spectra of heated and unheated jets can be attributed to differences in the stability characteristics of the jets.
Document ID
19810064213
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Maestrello, L. (NASA Langley Research Center Hampton, VA, United States)
Bayliss, A. (New York University New York, NY, United States)
Date Acquired
August 11, 2013
Publication Date
October 1, 1981
Subject Category
Acoustics
Report/Patent Number
AIAA PAPER 81-2008
Meeting Information
Meeting: Aeroacoustics Conference
Location: Palo Alto, CA
Start Date: October 5, 1981
End Date: October 7, 1981
Sponsors: American Institute of Aeronautics and Astronautics