Objective Objectives and content Objectives and content Since fan noise will be a major contributor to the exterior noise of Very High By-pass Ratio (VHBR) and Ultra High By-pass Ratio (UHBR) turbofans, aerospace industry is planning to introduce new nacelle noise reduction technologies as adaptive and active liners (actuators). Optimisation of these reduction means requires a thorough understanding and accurate description of the sound propagation in ducts. Therefore, the main goal of DUCAT is to develop, extend and validate computational methods for the propagation and radiation of fan noise, including the effects of acoustic liners. A number of relevant aspects of this topic are not covered by the computation models existing today. Duct acoustics design tools have to be reliable, accurate, fast and versatile. According to aerospace industrial needs, these models should ideally be able to handle: realistic nacelle geometries and non-uniform flow (in intake and by-pass duct), - non-uniform acoustic liners and duct wall mounted actuators, radiation into the far field, realistic frequencies and Sound Pressure Levels. Within short terms, it is not expected that all aspects can be addressed with a single model. Therefore in DUCAT a small number of numerical models (Finite Element (FEM), Boundary Element (BEM), coupled FEM/BEM, a non-linear propagation model and a ray-acoustics model) will be developed covering the whole frequency range of interest for fan noise (kRmax = 100). Focal points for the various models will be: for the BEM-model: acoustic radiation and the inclusion of non-uniform (potential) flow, for the 3D-FEM-model: acoustic radiation in sheared exhaust flow and 3-D nacelle geometry, for the coupled 3-D FEM/BEM model: influence of boundary layer flow on the effectiveness of liners, for the non-linear model: effect of liners on propagation just upstream of the fan, for the ray-acoustics model: high dimensionless frequencies (kR > 40). These models are partially complementary and partially overlapping, which offers the possibility to find the best modelling for each aspect of duct acoustics. The models will be validated by various experiments in European anechoic wind tunnels. A main validation experiment will be carried out using a model turbofan in the German Dutch Wind Tunnel (DNvV). The experimental data will constitute a database for the validation of the codes developed in this project and for future applications. Also data from the previously CECsponsored FANPAC-project will be used. After validation, the range of applications of the models and the restrictions for the use as industrial design tools for nacelle acoustic optimisation will be established. Furthermore, as a case study, a liner design exercise on the nacelle of a generic VHBR turbofan will be performed. The final result of DUCAT will be an assessment of the applicability of the various computational models for duct acoustics problems and liner optimisation. With the improved and validated models, the engine and aircraft industry will have the possibility to develop adequate design tools for both passive and active liner optimisation. Further some spin-off to other industries is foreseen, since fluid machines as pumps, fans and internal combustion engines are major noise sources in modern society. The work in this project will clearly make progress beyond the state of the art by developing and extending computational models for duct acoustics and validating those by a small number of precise experiments. Fields of science natural sciencescomputer and information sciencesdatabasesengineering and technologymechanical engineeringvehicle engineeringaerospace engineeringaircraftnatural sciencescomputer and information sciencescomputational sciencenatural sciencesphysical sciencesacousticsnatural sciencesmathematicspure mathematicsgeometry Programme(s) FP4-BRITE/EURAM 3 - Specific research and technological development programme in the field of industrial and materials technologies, 1994-1998 Topic(s) 0301 - Aeronautics Call for proposal Data not available Funding Scheme CSC - Cost-sharing contracts Coordinator Nationaal Lucht- en Ruimtevaart Laboratorium EU contribution No data Address 31,Voorsterweg 8316 PR Marknesse Netherlands See on map Total cost No data Participants (11) Sort alphabetically Sort by EU Contribution Expand all Collapse all AEROSPATIALE MATRA SA France EU contribution No data Address 316,Route de Bayonne 31060 Toulouse See on map Total cost No data BMW Rolls-Royce GmbH - Aeroengines Germany EU contribution No data Address 11,Eschenweg 15827 Dahlewitz See on map Total cost No data GERMAN - DUTCH WIND TUNNEL Netherlands EU contribution No data Address 31,Voorsterweg 31 8316 PR MARKNESSE See on map Total cost No data Groupe de Recherches et d'Animations pour le Développement, l'Innovation et l'Enseignement en Technologie France EU contribution No data Address Rue Personne de Roberval 60206 Compiégne See on map Total cost No data NATIONAL UNIVERSITY OF IRELAND, GALWAY Ireland EU contribution No data Address Nuns Island 90 GALWAY See on map Total cost No data OFFICE NATIONAL D'ETUDES ET DE RECHERCHES AEROSPATIALES France EU contribution No data Address 29,Avenue de la Division Leclerc 29 92322 Chètillon See on map Total cost No data ROYAL INSTITUTE OF TECHNOLOGY Sweden EU contribution No data Address 8,Teknikringen 8 100 44 STOCKHOLM See on map Total cost No data Rolls Royce PLC United Kingdom EU contribution No data Address Moor Lane DE2 8BJ Derby See on map Total cost No data TECHNICAL UNIVERSITY OF DENMARK Denmark EU contribution No data Address Anker Engelundsvej 1, Building 352 2800 LYNGBY See on map Total cost No data TURBOMECA SA France EU contribution No data Address Avenue du Président Szydlowski 64511 BORDES See on map Total cost No data UNIVERSITY OF SOUTHAMPTON United Kingdom EU contribution No data Address Highfield SOUTHAMPTON See on map Links Website Opens in new window Total cost No data
