Abstract: The cooling of the exhaust nozzle of a fan jet engine powering aircraft is enhanced by providing an extension cooling concept that includes an extension piece extending axially downstream of the nozzles variable throat that utilizes fan air to cool the forward portion of the divergent nozzle surfaces adjacent to the gas path of the engine and ram air to cool the surfaces downstream of the ejector. A variable vane varies the area of the ejector slot as a function of Aj for compensating for flow losses at off-design points of the nozzle positions during the flight envelope of the aircraft so as to avoid overtemperature of the components.

Abstract: The wall downstream of the slot of an ejector forms a divergent angle relative to the upstream wall adjacent to the slot so that the flow discharging from the slot expands and avoids having the primary air from pinching the secondary air and adversely affecting the cooling film issuing from the slot. When multiple slots in the ejector are utilized the downstream wall in relation to the upstream wall is similarly configured to obtain local multi-expansions.