Master theses / Diploma theses / Compulsory internship

Data acquisition in large industrial vessels such as bio reactor, biogas fermenters or wastewater treatment plants is limited to local measurement points due to the limited access to the vessel and the non-transparent fluid. To optimize these kinds of plants the three-dimensional flow field and the spatial distribution of e.g. temperature and electrical conductivity inside the vessel needs to be known. This can be done by the autonomous flow following lagrangian sensor particles (LSP) developed at the HZDR. Equipped with a pressure sensor, an accelerometer, two gyroscopes and a magnetometer, the sensor particle can track the flow movement inside of the vessels. From this, the flow field can be reconstructed.

To achieve a good flow following behavior, the density of the LSP can be adjusted before they are released into the vessel. While this works well for non-aerated systems, the influence of aeration on the flow following capability is unknown. Another unknown is how the velocities of the rising bubbles and of the continuous phase relates to the velocity measured by the LSP.
Therefore, the aim of this master thesis is to investigate the influence of aeration on the LSPs theoretically and experimentally by tracking the LSP with a camera. This includes the following tasks:

• Literature research on flow following behavior of large particles in fluids
• Experiments in a bubble column (330 mm ID) with LSPs and camera
• Data evaluation to retrieve the fluid velocity, bubble rising velocity and LSP velocity
• Comparison and conclusions on the flow following capability of LSPs in aerated reactors and comparison to the non-aerated case.

• Studies in the area of chemical or mechanical engineering or similar
• Basic chemical and fluid engineering knowledge
• Data analysis in Python
• Independent and structured way of working

• Immediate start possible
• Duration according to the respective study regulations