An aero/acoustic model test of a mixer-ejector nozzle was conducted at the 9 x 15 foot low-speed acoustic wind tunnel at NASA Lewis Research Center. The objective of the test was to get a preliminary assessment of ejector pumping and noise reduction potential of this device for possible application in the exhaust system of an advanced supersonic civil transport. The results of the test showed that goal levels of pumping were achieved. Exit pressure/temperature traverse data showed that there was good mixing between the primary and secondary streams. Acoustics data were dominated by shock noise; jet mixing noise levels were low because of a facility limit on primary temperature. The mixer-ejector did significantly reduce shock noise relative to the baseline conic nozzle. Because the relative magnitudes of jet mixing noise and shock noise were not in the correct proportion to properly model engine noise, an Effective Perceived Noise Level (EPNL) assessment was precluded.
[1]
W. Presz,et al.
Supersonic nozzle mixer ejector
,
1989
.
[2]
D. E. Harrington,et al.
Thrust performance of isolated 36-chute suppressor plug nozzles with and without ejectors at Mach numbers from 0 to 0.45
,
1975
.
[3]
Walter M. Presz,et al.
Parameter effects on mixer-ejector pumping performance
,
1988
.
[4]
G. C. Paynter,et al.
Development of acoustically lined ejector technology for multitube jet noise suppressor nozzles by model and engine tests over a wide range of jet pressure ratios and temperatures
,
1974
.
[5]
Shelby J. Morris,et al.
The challenges and opportunities of supersonic transport propulsion technology
,
1988
.
[6]
Walter M. Presz,et al.
Forced mixer lobes in ejector designs
,
1986
.