Liquid sodium (melting point ~ 98 [°C]) is a very attractive working fluid for thermal-hydraulic applications for concentrated solar power (CSP), nuclear and fusion applications. Sodium has – compared to water – a similar density, a lower dynamical viscosity and much higher thermal conductivity. That is, liquid sodium “flows better” than water and removes much more energy per unit surface than water.
Most turbulence models implemented in commercial and open-source CFD-codes apply the so called “Reynolds analogy” for calculating the turbulent heat transfer. This analogy is based on the assumption that the temperature field of the flow can be linked to the velocity field just by means of a constant. However, due to the high molecular heat conductivity of liquid metals, this assumption cannot be made for liquid metals. This imposes a major challenge in turbulence and heat transfer CFD-modelling of liquid metal flows, particularly in the natural- and mixed-convection cases, which are relevant for safety related analysis.
This is why researchers at KIT have recently developed new turbulence models coupled with heat transfer capabilities for liquid metals. Nevertheless, these models still need experimental validation. A vertical backward facing step experiment was designed and will be built into the DITEFA facility. The experiment is planned to be performed in October 2018. The codes already developed by KIT researches will then be able to be validated with experimental data.
The objective of the master thesis is:
- Adapt the already developed models to the current experimental setup.
- Run and post-process the CFD-cases according to the boundary conditions given by the experiment (LES and/or RANS).
The work includes:
- Creation of geometry, mesh, case setup, simulation, postprocessing (analysis of turbulent flow related quantities).
- Fluid mechanics, heat transfer, numerical analysis, basic turbulence concepts and RANS- and/or LES-turbulence modeling competence development.
- Writing the master thesis and present the results in a scientific colloquium.
Sufficient fluency in written and spoken English and/or German is required. First experiences with OpenFOAM and C++ programming language would round off your profile.
Duration: 6 Month
Starting Date: immediately
Supervisor: Dipl.-Ing. Thomas Schaub (E-mail: thomas.schaub@kit.edu).
Co-Supervisor: Dr.-Ing. Sebastian Ruck (E-mail: sebastian.ruck@kit.edu).
Professorial supervisor: Prof. Dr.-Ing. Robert Stieglitz
If interested, please send an application to thomas.schaub@kit.edu with your CV and your university grades.
This thesis/internship is restricted to a time window of 6 months.
