INNOVATIVE FLEXIBLE TURBINE EXHAUST

Due to the added weight of infrared suppressing exhaust systems, they are typically airframe mounted. Therefore, a flexible connection between the engine and the exhaust system is necessary. Bell Helicopter’s Propulsion Design Group has recently developed a bellows face seal system that eloquently solves the difficult problem of sealing in the demanding environment of high-temperature turbine exhaust with large relative motions and large diameters. This paper describes the complexities of a flexible exhaust seal design, previous design solutions, and the bellows face seal system. Next, the bellows face seal systems development, manufacture, and testing during its implementation on the V-22 Osprey program is described. A summary of its implementation on the H-1 programs is also presented. In conclusion, this paper describes the significant benefits of the redesign to both programs.