Final Report Summary - OPTIMAL (OPTImised Model for Accurately measured in-flight Loads) Executive Summary:Project summaryIn 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 Brag 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.Duration 30 months. Starting date 02 September 2013.Project Context and Objectives:Key objectives for the period • To integrate the proposed pylon load concept model• To investigate the contribution of the instrumentation techniques on the measurement errors.• The development of an optimised measurement concept for the pylon structure to achieve a targeted accuracy • The development of post processing capabilities for data acquisition• To design and manufacture of a small scale mock-up and its testing rig• The implementation and validation of the developed measuring system into the small scale mock-up • To propose a true scale flight worthy measurement system adapted to the CROR Flight Test demonstrator Project Results:Work performedThe project was divided in two periods P1 from 02/09/13 to 01/03/15 and P2 from 02/03/15 to 01/03/16.In the first period of the project, the technical work was essentially completed inWP1. There is ongoing work in WP2 to WP4. WP5 will start in next reporting period. All technical specifications of the work have been set and the inverse problem solution has been formulated. The first optimisation of the concept has been performed and the CAD of the initial mock-up has been produced.In the second period the ongoing work in all other WPs has been also completed. All technical specifications of the work have been set and the inverse problem solution has been formulated. The first optimisation of the concept has been performed and the CAD of the initial mock-up has been produced. The physical model is available and the tests have been performed. However the objective of 3% accuracy in the prediction of the loads was not achieved due to poor correlation between the measured and the computed strains. Consequently, although the inverse methodology has proven to be robust in theoretical cases that were examined it was not possible to yield the desired outcome at this stage. In order to achieve this goal the partners will continue with relevant investigations outside the OPTIMAL project and on their own expenses.Results achieved The main output of the reporting period was:• A set of specifications on Pylon mock-up, sensor array configuration. Definition of Data Acquisition System (DAS) and translator software (s/w) specifications.• Definition of mock-up test plan (test matrix, loading conditions, hardware)• The first initial detailed numerical model has been produced and analysed.• The inverse problem solution has been formulated• A set of specifications on Pylon mock-up, sensor array configuration. Definition of Data Acquisition System (DAS) and translator software (s/w) specifications.• Definition of mock-up test plan (test matrix, loading conditions, hardware)• The first initial detailed numerical model has been produced and analysed.• The inverse problem solution has been formulated• Realisation of a of the Data Acquisition System (DAS) that can fuse information from optical (FBG) and electrical (Strain Gauge) sensors.• Finalisation of mock-u CAD design• Fabrication of the physical test article• Proposal for an adapted concept on suitable for aircraft environment • Execution of Test Matrix for Mock-up tests • Analysis and results of the lab tests. Delivery of Pylon hardware• Discuss of Scale up feasibility with the synthesis of the work and proposal of a way towards TRL6Potential Impact:ImpactThe use of OPTIMAL system once validated, is expected to find applications in other structural problems where load identification is necessary and can't be directly known. Furthermore, it could be combined with Structural Health Monitoring systems in order to increase it's accuracy and prediction capability in order to achieve significant reduction in maintenance downtime and cost. Eventually OPTIMAL is expected to increase reliability and safety having great importance in aeronautic transport.List of Websites:Coordinator’s DetailsMr. Dimitri KaragiannisINASCOE-mail: d.karagiannis@inasco.comPhone: +30-210- 9943427Fax: +30-210-9961019 Powiązane dokumenty final1-optimal-final-summary-v02.pdf
