Reliability Based Design and Analysis of a Twin-Shaft Turbofan Engine

In this paper a double-shaft turbofan engine is considered to be in the design phase. Therefore its environmental condition and critical source of failures has been studied and the subsystems and components has been identified. Since it is in design phase, the project encounters to the lack of specified failure data. To overcome this problem, the generic data or expert judgments on the basis of environmental condition is used. Then Simulation process utilizing Reliability Block Diagrams and implementation of Monte Carlo Method has been done. The results involve reliability evaluation of system and Reliability Importance. The engine has less than 97 percent reliability in 150 flight hours. Finally a Reliability Allocation method has been utilized to improve the reliability measure to 97 percent in 300 flight hours. Results reveal that oil and fuel filters and pumps and the disks and blades of rotating subsystems are the most sensitive and critical parts of engine.