OPTIMAL · OPTImised Model for Accurately measured in-flight Loads

In recent years, Counter Rotating Open Rotors (CROR) have received considerable attention as the CROR concept promises a considerable reduction of fuel consumption over conventional ducted turbofan engines. Specifically for Smart Fixed Wing Aircraft CROR is expected to contribute to 20% fuel burn reduction. Despite this potential CROR engines are associated with higher noise and vibration levels and their installation pauses a challenge for the adaptation in future aircraft models. The main objective of OPTIMAL proposal is to provide a technical solution to accurately measure all the loads encountered by a pylon which supports a Counter Rotating Open Rotor (CROR) engine in flight. The work entails the development of a methodology that will enable the assessment of flight loads on to the pylon and fuselage based on local sensor measurements. This methodology is based on an inverse Finite Element Analysis (FEA) approach where the loads at the boundaries i.e pylon-fuselage attachment can be assessed with increased accuracy and fidelity.FEA analysis will be supported by accurate strain, temperature and acceleration measurements by an appropriate sensor network. Traditional sensors such as strain gauges and accelerometers as well as optical fiber sensors Bragg Gratings will be investigated and analyzed. The two proposed sensor networks systems will be operating side by side in an effort to evaluate optical system performance and eventual feasibility for the pylon monitoring application. To this end the proposers will bring in their background knowledge and no further development of the optical measuring system is foreseen.The proposed approach will be validated by structural testing of a scaled pylon mock-up, which will be representative of the real structure. Based on the results of these investigations, a true scale measurement system configuration will be proposed that should meet Flight Worthiness specifications of the future flying test bed.