[Reports] / Amer.inst.of aeronautics and astronautics. N 90-3949 : measurement of acoustic suppressions in a flow duct using an energy flux measurement technique : Rep.presented at AIAA 13th aeroacoustics con.,Oct.22-24,1990,Tallahassee,Fl. / A.A.Syed,D.L.Lewis, 1990. - 8 p. - Текст : непосредственный.