The ejector has a length to diameter ratio of about 2:1 and has a 36-inch inner diameter. The dimensions of the ejector were the result of a compromise between the benefits of a) increasing air flow for jet mixing and b) length required to absorb high frequency noise within the ejector, and the liabilities of y) additional weight and z) cruise performance impact - other than additional drag created by ejector. The ejector inlet is designed to provide a continuously accelerating airflow to the mixer lobe exit ensuring the flow follows the lobe lines, resulting in optimum mixing with minimal air flow losses.
The design also assures that any choking of the secondary airflow occurs at or after the mixer lobe exit, which again ensures minimal losses. The ejector is attached directly to the fuselage in order to eliminate any added stress on the engine. The inner surface of the ejector is treated with acoustical lining to absorb the high frequency jet noise generated by the mixer lobes’ effective conversion of low frequency noise into high frequency noise.
