In reciprocating engines, it is now widely agreed that many of the combustion processes are determined principally by the aerodynamics of the flow (for example, the heat-transfers, the flame propagation and its blow-up close to the walls). To investigate this kind of flow, the theoretical analysis of the Navier-Stokes equations is limited to asymptotic tendencies; on the other hand. experiments can only provide a limited number of measurements, because of practical limitations. Therefore, the numerical simulation provides an interesting and complementary way to study intensively the flow in an internal combustion engine. However, this last approach is generally based on the statistical approach of turbulence. Therefore. there is an urgent need to test and eventually improve the physical models used for the statistical description of turbulence. The main objectives of this research are therefore: 1) to develop numerical models (based on the resolution of the instantaneous Navier-Stokes equations) for flows in an idea]ized internal combustion engine; 2) to-use -these numerical codes to produce a numerical data base for different test cases; 3) to compare the results with other idealized test cases; 4) to investigate and eventually improve the statistical turbulence models used in engineering fro m the built-in data base. Training content (objective, benefit and expected impact) At first, I will extend my knowledge on experimental methodology (by interacting with people in charge of experiments) and on turbulence modeling at Erlangen with Professor Tropea and his co-workers. I will also widen greatly my experience and competence in the field of the direct numerical simulation in fluid mechanics with the Friedrich's research team at Munich. Moreover, as the LES approach should become more and more attractive and powerful for many industrial situations, I think that this combination of research training and mobility will be invaluable in finding thenafter a permanent employment in the European Community, either in higher education, a public research organization or in industry
Links with industry I industrial relevance (22) The practical interest of the project resides in the evaluation of the turbulence models commonly employed in the numerical codes used by the car manufacturers. Also, the results should provide new insights into the relevance of the use of classical wall-functions, and should indicate what kind of near-wall modeling should be recommended for the industrial research. And the participation of one major car manufacturer in the JOULE III project should ensure the transfer of technology to industry.