Research

The heat transfer forms a central role  in thermal and power engineering processes. Despite the high state of development of power plant and turbo machinery technology, we are still facing a lot of heat transfer challenges.

Therefore our research activities are focused on the following thermal engineering projects:

• Convective heat transfer of rotating disks in crossflows
• Design and optimization of ORC turbines using large-eddy simulations
• Evaporation on high performance diamond heating surfaces
• Flow phenomena and heat transfer of journal bearings in heavy-duty gas and steam turbines

The interest in resource-saving energy generation has grown massively in the last few years. In this context the Organic Rankine Cycle (ORC-Process) represents a huge potential because of its utilization of low-temperature sources, especially in times of "energy revolution".

Compared to traditional thermal engines, the ORC process operates at relatively low maximum temperatures. To achieve an acceptable overall efficiency high turbine efficiencies are therefore necessary, caused by the limited thermal efficiency.

The challenge here lies in the demanding properties of the organic working fluids whose loss mechanisms are still largely unknown in the field of unsteady supersonic flow.

The heat transfer on rotating disk systems can be found on numerous application in the field of thermal, turbo machinery and power engineering. For the thermal design correlations of the heat transfer as function of different parameters like disk thickness, rotational rate, crossflow speed and angle of incidence are necessary. In this project we focus on experimental measurements and Large-Eddy-Simulations of the heat transfer and flow field behavior of free rotating disks in a forced flow. The results our investigation can be used from the designing of disk brakes to the better understanding of flow phenomena in turbo machinery.