An experimental study of 2-D mixer/ejector noise and thrust characteristics

Models of two/three-position jet noisesuppression nozzles for future supersonic aircraft were acoustically tested under take-off conditions. The tests were conducted simultaneously at the outdoor acoustic facility at CIAM and at the wind-tunnel thrust facility at TSAGI. The mixer-ejector noise-reduction nozzle consists of a multi-lobe two-dimensional nozzle with an acoustically-treated ejector. The influence of the nozzle's basic geometric parameters (number of lobes, shape of lobes, length of ejector) on its noise and thrust performance was investigated. Thrust measurements were made in the external airflow with Mach numbers up to M = 0.6.