Abstract: A mixing nozzle for an aircraft turbine engine having an improved aerodynamic stiffening ring secured to the lobes of the mixer. Aircraft turbine engines having a rearwardly discharging nozzle are often provided with a mixer having a generally circular forward end adapted to be attached to an engine and axially deepening corrugations leading to a multi-lobed aft end surrounding the nozzle. This mixer mixes ambient cool air with the hot gases exiting the engine thus suppressing engine sound. The lobes are generally unsupported and subject to vibration and excessive deflections in use. A circumferential stiffening ring is secured to the aft end of the mixer to reduce or prevent the vibration while simultaneously enhancing the mixing of cool ambient air with the hot engine exhaust. The stiffening ring preferably has an airfoil cross-section for lowest drag combined with the ability to direct flow past the ring in a selected optimum direction.

Abstract: A method and apparatus for bonding high temperature structures, such as face sheets to high performance honeycomb cores, using differential gas pressure at high temperatures. A high temperature resistant, foil sheet having a thickness of from about 0.0005 to 0.003 inch is welded to a support to form a vacuum bag to surround the structure to be bonded. A vacuum line is connected to the bag to allow evacuation of the bag. Typically, the structure is bonded in a vacuum furnace. Initially, the furnace is heated to the bonding temperature of the assembly while both the furnace chamber and the vacuum bag are substantially completely evacuated. Then slight pressure is allowed to return to the chamber to force the foil sheet into intimate presure contact with the structural assembly to bring the components tightly together, using the relative pressure different between the vacuum in the chamber and the vacuum within the bag.