Research objectives and content
Jet noise is the major contributor to the acoustic pollution around international airports. This study is focused on understanding the physics of supersonic jet noise production and radiation whose reduction is specifically pertinent to the development of the next generation supersonic civil transport projects, involving the supersonic High Speed Civil Transport(HSCT).
Correctly expanded hot jets from axisymmetric coaxial nozzles develop a complex unsteady flow pattern. A turbulent mixing region is featured at the high Reynolds number range of the 'Concorde' engine jets, the only European supersonic civil transport aircraft. The flow unsteadiness within it accompanies an intense acoustic radiation. A joint computational fluid dynamics and computational aeroacoustic method will be developed to study the noise radiation from unsteady high Reynolds number flows. To predict the near flow field, the discrete short time averaged Navier-Stokes equations with turbulence closure will be solved using two different aerodynamic solvers and the results will be compared in terms of accuracy and efficiency: The first one is a Finite Volume solver on orthogonal grids, based on Coquel and Liou's hybrid flux difference split approximate Riemann solver and four step Runge-Kutta time integration. The second one is an implicit time integration solver on an unstructured grid based on multidimensional upwind schemes recently developed at the host institute. The instantaneous and time averaged flow solutions provide the source terms for the Ffowcs-Williams and Hawkings intergral far field acoustic pressure numerical estimator. The results will contribute to the understanding of aerodynamic noise and aid the design of quiet engines. Training content (objective. benefit and expected impact)
The applicant is expected to benefit his professional development by working in a centre of academic excellence such as the host institute. The local expertise in theoretical and computational fluid dynamics (Prof. Deconinck) and in the fluid dynamics of supersonic jet flows (Prof. Charbonnier) will be a valuable asset for the successful completion of the research project. Specifically previous numerical and experimental studies of high Reynolds number supersonic flows conducted at the host institute will aid the development and validation of the numerical method. As the host institute has an established industrial contract research, exposing the research to industry and adapting it to its requirements will form an important part of the training content. The completion of the project will significantly enhance the trainee's expertise in computational aspects of jet noise, a highly valuable field of expertise for the European aerospace industry.
Links with industry / industrial relevance (22)
This study is relevant to the aircraft industry. This sector is of strategic interest to the European Community which set up a specific Research Industry Task Force. Specific reference to aircraft noise abatement is made in the 'New Generation Aircraft' Research Industry Task Force. It is intended to collaborate in this European Union project in the second year of research to explore possibilities of further developing the jet noise predictor as an industrial engine design tool. The host institute will investigate aal possibilities for exploitation of the research with its industrial contacts in aerospace industry.
European Union project in the second year of research to explore possibilities of further developing the jet noise predictor software as an industrial engine design tool. The host institute will investigate ali possibilities for exploitation of the research with its industrial contacts in aerospace industry.