Report
Teaser, summary, work performed and final results
Periodic Reporting for period 1 - WTM-RECYCLE (Large scale wind tunnel turboprop aircraft model integrating morphing devices for aerodynamic experimental assessment)
Teaser
Existing turboprop configurations are very efficient at cruise speeds up to about Mach 0.65 providing a fuel savings of 10 to 20 percent with respect to equivalent technology turbofan aircrafts. On the other hand, above this speed, the increased drag due to compressibility...
Summary
Existing turboprop configurations are very efficient at cruise speeds up to about Mach 0.65 providing a fuel savings of 10 to 20 percent with respect to equivalent technology turbofan aircrafts. On the other hand, above this speed, the increased drag due to compressibility losses on the propeller blades causes efficiency to fall rapidly. Now, with the use of composite materials and advanced construction techniques, it is possible to construct propeller blades with thinner airfoil sections and more optimum shapes (sweeping the blade leading edge, scimitar geometry, etc) that can operate in high subsonic conditions (up to M=0.8). The integration of turboprop engines into the airframe, and the design of high-lift devices for landing and take-off, presenting some unique aerodynamic challenges in particular when utilizing natural laminar flow wings for additional drag reduction.
Regional mobility is of fundamental importance for regional economic and social development by connecting countries, people and cultures. Here, regional air transportation is of crucial importance by integrating with the global network of air transportation. In this respect, novel turboprop designs will contribute to environmentally friendly and sustainable means of transportation.
WTM-RECYCLE – Large scale wind tunnel turboprop aircraft model integrating morphing devices for aerodynamic experimental assessment – addresses the call JTI-CS2-2016-CFP04-REG-01-05 and will contribute to the knowledge base and technical development for sustainable regional air transportation. The overall objective of the project is to support the development and assessment of new and conceptual versatile aerodynamic control surfaces, and high lift technologies as well as turboprop integration effects. The WTM-RECYCLE project focuses on the modification of a wind tunnel model for delivering aerodynamic data that allows analyzing the aerodynamic performance of innovative control surfaces and high-lift devices including powered propellers. In specific, the objective is to study the effect of morphing devices for drooped wing leading edge, geometry morphed flaps and winglets in landing and take-off configurations including propeller installation effects. The main outcomes are detailed wind-tunnel measurements as well as complementary numerical CFD analyses for studying the flow details and scaling to real conditions.
An existing wind-tunnel model will be redesigned, with the aims of maximizing the use of the existing hardware with consequent reduction of new components and therefore reducing waste production, energy consumption and pollutions emissions within the project itself. A large-scale demonstrator was designed and build in an upfront project. Using it here effectively halves the resources needed to generate results.
Work performed
The geometrical design of the wind-tunnel model has been completed. The original plan was extended by introducing exchangeable wing geometries in order to fully take advantage of outcome from parallel activities on the design of natural laminar wing. This required a careful redesign of the wind tunnel model due to the complex design of the inboard wing chore structure which carries the hydraulic high-pressure connections. This has been achieved in a way that a fast exchange in the wind tunnel between both wing geometries is ensured.
The detailed structural design of the wind tunnel model is basically completed where the correct wing geometry is implemented by interchangeable parts mounted on an internal core structure. The desired droop nose is implemented by changing the wing configuration.
The old wind tunnel model has been restored. Detailed laser measurements have been made for verification and possible corrections. Existing pressure taps have been verified and tested. The flap balances have been tested and further improvements are ongoing. Activities on tools design and preparation for manufacturing of the new components are ongoing.
Work on a modularized and parametric meshing procedure is ongoing in order to enable fast and automatic CFD analysis for WT comparisons and extrapolation to free flight. The surface mesh is virtually structured on the critical regions for highest possible accuracy. Preliminary computations show good accuracy and convergence as well as efficient high-performance computing performance. The CFD analysis includes the full geometry because of asymmetry due to the co-rotating propeller installation also included in the CFD model by a propeller disk model.
Final results
The core activity is to achieve an aerodynamic database of the innovative turboprop aircraft model integrating innovative leading-edge and trailing-edge high-lift devices. The upcoming aerodynamic large-scale wind-tunnel tests planned in September 2019, will complete the assessment of the GRA turboprop aircraft configuration providing relevant data about the effectiveness of such promising high lift morphing concepts. The related CFD analyses will provide important additional information about the scaling to free-flight conditions as well as details about the flow.
As widely known, the Clean Sky program aims to develop innovative and environmentally friendly products. To reduce COX emissions and waste in aircraft component manufacturing incrementing the use of recycling materials are some relevant steps for achieving such important goals. The upcoming outcome from wind tunnel test and CFD study will help to validate the work done within the Clean Sky REG-ITD. Morphing is a key technology for future improvements, a large-scale demonstrator such as the LOSITA/WTM-RECYCLE model will help to showing the benefits that can be obtained and therefore push the work of the ITD.