Final Report Summary - SHEFAE (Surface Heat Exchangers for Aero-Engines) Executive Summary:Surface coolers are an integral feature of advanced turbofan engine designs. Oil is cooled by the passage of cool engine bypass air flow over the air washed surface of the heat exchanger. The current surface coolers are parasitic to the existing engine structure, and occupy surfaces that can also be used for acoustic treatment to control engine noise. The design and installation of a compact and lightweight structural surface cooler in a core fairing structure will contribute positively to the efficiency of the power-plant by providing the necessary oil cooling at minimum overall weight and hence optimal fuel burn.The Project aim was to develop and demonstrate an advanced structural surface cooler (ASSC) mounted in an appropriate core fairing composite structure; termed the Mount Composite Structure (MCS). The project met all of its objectives and, as a result, the ASSC and MCS technology is on plan to enable the next generation of fuel efficient aero-engines such as the Rolls-Royce UltraFanTM. Project Context and Objectives:The Project aim is to develop and demonstrate an advanced structural surface cooler mounted in an appropriate core fairing composite structure. Currently surface coolers are an integral feature of advanced turbofan engine designs. They contribute to achieving the best engine performance by maintaining oil and fuel temperatures within defined limits and by virtue of their mounting on the inside of the fan case they obviate the need for additional ducting of air and a control valve to switch the air on/off. The lack of ducting and control valve leads to an overall cost and weight reduction. Oil and/or fuel is cooled by the passage of cool engine bypass air flow over the air washed surface of the heat exchanger. Current surface coolers are parasitic to the existing engine structure, and occupy surfaces that can also be used for acoustic treatment to control engine noise. As such the weight, volume and efficiency of the surface cooler are all of great importance. The design and installation of a compact and lightweight structural surface cooler in a core fairing structure will contribute positively to the efficiency of the power-plant by providing the necessary oil cooling at minimum overall weight and hence optimal fuel burn. It is envisaged that surface cooler/composite core fairing designs will evolve that employ novel structural design, advance manufacturing techniques, potentially novel materials and new concepts in utilising air washed surfaces on the engine. The structural integration of the metallic structural surface cooler to a composite core fairing type structure has been identified as an important area for success. The joint must allow a strong load path, handle dissimilar degrees of thermal displacement and provide sealing yet being light and durable. Therefore mounting of such a surface cooler in a composite core fairing structure will also be researched for future engines where composite air washed structures may be used.The Project Objectives are listed by Work Package (WP) below:WP1 (Specification and Assessment):• Create a design specification and an interface control document (ICD) for the Advanced Structural Surface Cooler (ASSC)• Create a design specification and an Interface Control Document (ICD) for the Mount Composite Structure (MCS)• Assess project achievements towards objectivesWP2 (Design of Components):• To design and optimise an advanced structural surface cooler to be mounted and tested on a Rolls-Royce (RR) demonstrator engine• To conceptually design and optimise a MCS including provision for mounting a heat exchanger.• To develop technologies enabling a light and safe MCS in polymer composite material• To design a simplified MCS for test rig verificationWP3 (Make and Build):• To manufacture ASSCs in accordance with the design agreed in WP2• To manufacture MCS panels in accordance with the designs agreed in WP2• To integrate the ASSC on a demonstrator engine or rig.WP4 (Validation Tests):• To conduct rig testing of the ASSC and MCS• To conduct testing of the ASSC on demonstrator engine to demonstrate its capability to TRL6WP5 (Project Management):• Coordination of the project• Preparation of reports, claims and project reviews• Managing the consortium, including project risk and IPWP6 (Dissemination):• To provide the SHEFAE dissemination means:• Prepare and distribute dissemination material• Arrange SHEFAE participation to public workshops/conferences• Transfer technology to exploit the project resultsProject Results:The objectives for all work packages were achieved by the Project and all deliverables have been completed.Specifications for the ASSC and the MCS were completed and are representative of requirements for modern gas turbine engines. The technology level for a MCS in such a challenging environment was very low at the start of the project. The material capability, the manufacturability and the mechanical design challenges were not well understood across the industry. This project has significantly progressed that understanding on all fronts. A competitive design offering weight savings of 20% versus the current state of the art was produced by GKN. Following SICOMP’s computational process modelling of the manufacturing technique, the manufacture of the design was successful with relatively good quality parts being produced straight away. A major risk for composite structures is how they attach to the surrounding composite or metallic parts. The failure mechanisms for composite bolted joints at a range of operating conditions were investigated by INEGI and analysis models developed to predict such failures under wide ranging conditions. These models will allow companies such as GKN and RR to produce accurate, well-optimised designs with higher confidence in eventual successful component-level validation. The performance of a selection of material resins under fire conditions was also assessed and the best performing resin (MHT-R) declared. Models to evaluate the performance of surface coolers were created by the University of Tokyo and show good correlation with both rig and engine testing. In addition to this, the key design parameters were established and the fundamentals are in place for a design tool that can optimise (maximum heat dissipation per unit volume and therefore mass and cost) surface coolers for a range of conditions and space envelopes.The ASSC was designed and manufactured by SPP. It did not meet the ambitious performance target set but it did demonstrate a good correlation to predictions. This was expected and understood by the consortium as the design constraints to fit onto an existing engine for testing limited the possible performance. The work performed in SHEFAE gives RR and SPP confidence in the design tools that can be used for future engine architectures such as the UltraFanTM where the traditional locations are no longer available. The architecture of the UltraFanTM is predicted to improve fuel burn by 25% versus the early Trent engines such as the Trent 700. By combining parts where two parts deliver two functions into "multifunctional" designs such as the ASSC where one part delivers the two functions; weight and costs savings will be achieved.The project met all of its objectives and, as a result, the ASSC and MCS technology is on plan to enable the next generation of fuel efficient aero-engines such as the Rolls-Royce UltraFanTM. Potential Impact:This project developed technology for civil aerospace applications in Europe and Japan. The technology was developed by aero-engine manufacturer Rolls-Royce in conjunction with companies in its supply chain and supporting research organisations including universities. The project supported employment in these organisations during its course and has helped to develop the competitiveness of products for Rolls-Royce and its supply chain which will benefit employement in Europe and Japan in the future. The Project also enhanced social and industrial links between Europe and Japan.The project also delivered environmental improvements through reduced fuel burn of aerospace products through weight efficient solutions and by enabling more efficient engine architectures of the future.There were many dissemination activities that took place relating to this project. They were in the form of conference presentations plus journal publishings and also a master thesis was published. INEGI also held a Promo-Air event, designed to help raise the interest of young Europeans towards scientific and technical studies in the field of Aeronautics and Air Transport. A full list of dissemination activities is listed in this report.There were no further societal implications.List of Websites:There was not a public website created for this Project.Key contacts are listed below: Ben Williams, Chief of Research and Technology and SHEFAE Project Coordinator. Rolls-Royce plc. Email: ben.williams2@rolls-royce.comSusumu Tomida, Section Manager. Sumitomo Precision Products. Email: tomida@spp.co.jpProf. Toshinori Watanabe. University of Tokyo. Email: watanabe@aero.t.u-tokyo.ac.jpAnders Sjunnesson, Technology Manager. GKN. Email: anders.sjunnesson@gknaerospace.comPatrik Fernberg, Senior Researcher. SICOMP. Email: Patrik.Fernberg@swerea.seProf. Pedro Camanho. INEGI. Email: pcamanho@inegi.up.pt
