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

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  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

• 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

• A full-time position for four years, with a qualifier in the first year, and the flexibility to work (partially) from home.
• Your salary and associated conditions are in accordance with the collective labour agreement for Dutch universities (CAO-NU).
• You will receive a gross monthly salary ranging from €3.204 (first year) to €4.051 ,- (fourth year) (filled in by HR)
• There are excellent benefits including a holiday allowance of 8% of the gross annual salary, an end-of-year bonus of 8.3%, and a solid pension scheme.
• A minimum of 232 leave hours in case of full-time employment based on a formal workweek of 38 hours. A full-time employment in practice means 40 hours a week, therefore resulting in 96 extra leave hours on an annual basis.
• Free access to sports facilities on campus.
• A…