燃烧噪声方向博士职位

Simulation-based development of indirect combustion-noise theory

To remedy ineluctable deficiencies in the current understanding of indirect-noise generation, especially as it relates to hydrogen-fueled systems, Computational Fluid Dynamics (CFD) will be used. Initially, numerical analyses will focus on a previously used experimental setup operated at DLR. As a first step, non-reacting-flow modelling will be employed to definitively establish the cogency of non-reacting-flow simulations for systems with reacting flow. Moreover, this analysis will improve comprehension of the turbulent and thermodynamic processes, which influence combustion by considering them in isolation. Three-dimensional non-reacting-flow simulations using lower-fidelity numerical models for compressible flows (Euler and URANS) will be compared to high-fidelity non-reacting-flow LES results to evaluate the predictive quality of lower-fidelity CFD methods. After that, the lower-fidelity simulations will be repeated including the combustion of classical hydrocarbons (methane) and hydrogen. The resulting numerical datasets will then be exploited to perform theory development. Notably, an effort will be made to elucidate the effect of the interplay between vorticity, compositional and entropy spots on indirect noise. Ultimately, the aim is to extend existing analytical/semi-analytical modelling to hydrogen combustion.

Research Objectives (1) CFD studies of vorticity inhomogeneities convected by a high-Reynolds-number flow through a choked nozzle under non-reactive simulations. (2) Non-reactive Euler/URANS/LES-simulation comparison of entropy-vorticity interaction with a choked nozzle. (3) Quantification of the effects of combustion on noise spectra.(4) Development of analytical/semi-analytical models. Expected Results (1)Vorticity/entropy interaction as a source of indirect noise. (2) Comparison with classic hydrocarbons configuration. (3) Analytical model for indirect noise due to vorticity/entropy interactions

Secondments TU Delft (Netherlands, ca. 3 months): work on the development of new functionalities in a numerical-simulation-tool for indirect-noise investigations ETH Zurich (Switzerland, ca. 2 months): to perform experiments on indirect noise

The candidate must not have resided or carried out their main activity in the country of the host organization for more than 12 months in the 36 months immediately before the call deadline or recruitment date