PhD position on indirect combustion noise; Fluid Mechanics; CFD; Aeroacoustics

Job description

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

Requirements

• You have a MSc degree in the field of (Applied) Physics, Applied Mathematics, Aerospace Eng., Mech. Eng., any of the above with a demonstrable specialization in Fluid Mechanics.
• You have very strong fundamentals in Fluid Mechanics as it relates to the theoretical framework and/or numerical methods & Computational Fluid Mechanics (CFD) best practices.
• Scientific communication skills
• Minimum level of English proficiency: C1 (CEFR) or equivalent
• Academic writing; viz., a demonstrated ability to produce cogent & concise scientific texts
• Authorship of a peer reviewed publication in a pertinent journal or as a proceeding of a conference with standing is a plus
• Produce cogent oral presentations

Additional information

• Are you interested in this position? Please send your application via the 'Apply now' button below before …, and include:
• A cover letter (maximum 2 pages A4), emphasizing your specific interest, qualifications, motivations to apply for this position.
• A Curriculum Vitae, including a list of all courses attended and grades obtained, and, if applicable, a list of publications and references.

For more information regarding this position, you are welcome to contact (Lionel. Hirschberg (l.hirschberg@utwente.nl )