Research on the noise produced by military aircraft has seen a renewed interest due to the increasing concerns of communities around airbases and airports. Radiated noise associated with high-speed military style engines is the main contributor of the overall noise produced by modern aircraft, especially in military applications where the jets typically are at very high velocity and temperature, and have low bypass ratios. The acoustic and aerodynamic properties of high-speed jets are investigated experimentally in this thesis. Measurements are conducted in the Penn State high speed jet noise facility, after the validation of the newly upgraded rig. Axisymmetric Nozzles are investigated as well as nozzles with a military style shape.Addition of a second fan compresses the air upstream of the anechoic chamber and hence provides the additional pressure drop required for high air speed. The whole ... Work has been carried out in order to seal as best as possible the anechoic chamber and hence reduce the pressure losses due to any leak. ... The volume flow rate necessary in order to reach the target speed is around 6.6m3/s ( 14, 000 CFM). ... An assembly drawing of the whole upgrade is shown in Figure A -7.
|Title||:||On the Characterization of Noise Sources in Supersonic Shock Containing Jets|
|Publisher||:||ProQuest - 2008|