JOB DESCRIPTION

Stratified flows, where fluid density and viscosity vary strongly, are common in both natural and industrial systems—ranging from ocean currents to advanced heat exchangers. However, conventional models like the Boussinesq approximation fail to capture the complex physics in such flows when strong stratification or non-ideal fluids are involved.
Within this PhD, you will advance our understanding of hydrodynamic stability and turbulence in strongly stratified turbulent flows, such as fluids at supercritical pressures, where extreme property variations create strong stratifications. Using linear stability analysis and direct numerical simulations of the fully compressible Navier–Stokes equations, you will explore how inertial and gravitational baroclinic mechanisms interact to trigger or suppress the transition to turbulence and how they affect the fully turbulent flow.
The work is embedded in a broader project combining theory, computation, and unique high-pressure experiments. The insights gained will inform more accurate models for a wide range of stratified shear flows and contribute to the design of efficient next-generation energy systems.

Key tasks include:

• Developing a theoretical framework for stratified shear flows that includes gravitational and inertial baroclinic instability mechanisms.
• Deriving and analyzing evolution equations for flow disturbances.
• Running DNS with advanced multi-GPU solvers using accurate real-fluid equations of state and variable properties.
• Interpreting results in close collaboration with an experimental PhD and validating findings against experimental data.

You will be embedded in a multidisciplinary team with expertise in numerical methods, compressible flows, and turbulence in non-ideal fluids, and work in synergy with an experimental PhD student studying the same flows in the laboratory.

JOB REQUIREMENTS

We seek an enthusiastic and motivated candidate with:

• A Master’s degree (or equivalent) in mechanical engineering, applied physics, aerospace engineering, or a related field.
• A strong background in fluid mechanics, numerical methods, and thermodynamics.
• Experience with computational fluid dynamics (CFD); prior exposure to DNS or stability analysis is a strong plus.
• Solid programming skills (e.g., Python, C/C++, or Fortran); experience with GPU computing or high-performance computing is beneficial.
• The ability to work independently as well as collaboratively in an interdisciplinary environment.
• Good command of English, both written and spoken.

• Developing a theoretical framework for stratified shear flows that includes gravitational and inertial baroclinic instability mechanisms.
• Deriving and analyzing evolution equations for flow disturbances.
• Running DNS with advanced multi-GPU solvers using accurate real-fluid equations of state and variable properties.
• Interpreting results in close collaboration with an experimental PhD and validating findings against experimental data