A method for identifying structural load share opportunities in aircraft powerplant configurations

Abstract

Future civil transport aircraft will be powered by next generation high bypass ratio engines which will have larger fan diameters producing higher levels of thrust. Consequentially structural and thermal demands will increase on individual power plant components. Under current design practice the various sub-systems (for example: nacelle, inlet, thrust reverser, engine core casings and the pylon mounts) are designed independently to meet their individual specific functional requirements. This results in inefficiencies in the overall system and a lack of understanding of how such structures behave as one unit.

With the application of bigger engines, the structural inefficiencies caused by current design practices may be magnified. To overcome this challenge, it is vital that all sub-systems contribute to the structural integrity and load carrying capacity of the overall powerplant system. This can only be achieved if the main structural components of the power plant are to be designed as a single structural unit: using the inherent load carrying capacity of the surrounding nacelle components to ‘share’ or relieve structural loading on the primary engine sub-system.

This research formulated and demonstrated a novel method for identifying optimal connection strategies between powerplant components for more efficient sharing of structural loads and improving engine structural performance. Modelling approaches were developed to allow for the ability to easily alter the sub-system connections and locations. A design of experiments approach based on key engine structural performance metrics was utilised to evaluate the impact and effectiveness of the proposed optimal connection strategies. Successful completion of this research delivered an analysis capability to determine the impact of varying sub-system interface structural function and location, on the distribution of flight load cases. Such capabilities do not currently exist.

These methods were demonstrated in a large turbofan engine representative of those in service in civil aircraft today. The research generated a novel understanding of structural interaction between primary engine sub-system and surrounding TRU and nacelle components as they were analysed as a single unit. The research identified new attachment schemes between the engine core components and the surrounding TRU component. The novel connection strategy included the introduction of a new rotational and axial connection between the aft section of the rear turbine and the TRU inner barrel, and a rotational restraint at the inner V groove.

Date of Award	Jul 2022
Original language	English
Awarding Institution	Queen's University Belfast
Sponsors	EPSRC Internal Schemes
Supervisor	Adrian Murphy (Supervisor), Damian Quinn (Supervisor) & Trevor T Robinson (Supervisor)