Successful Diploma Thesis Defense of Ina Naujokat

We proudly announce that Ms. Ina Naujokat has successfully defended her diploma thesis on the topic “Numerical simulation of heat and mass transfer to enhance thermal management of nanopositioning systems.”

Nanopositioning systems are used in semiconductor production as well as in optics, microscopy, and nanotechnology for the positioning and for the processing of objects with high precision. One special method of positioning is to drive sliders via a system of planar actuators that are based on electromagnetic principles. During operation, within the coils of such a drive unit, heat is generated due to ohmic losses. This internal heating induces temperature gradients that in turn impair the positioning accuracy via thermal expansion of the materials used. Therefore, effective and efficient convective cooling of the entire device is crucial for precise operation. In her studies, Ms. Naujokat  employed the CFD code ANSYS/FLUENT to simulate the effects of forced convection of a coolant pumped through microchannels of complex geometry on the heat transfer characteristics under various thermal loads and flow rates. Of special fluid-mechanical interest is the appearance of Görtler vortices formed in the U-turns of the channel system. 

The thesis was scientifically embedded in a joint research project of our group with the IMMS GmbH in Ilmenau and was supervised by our colleague Christian Karcher and by Dr. Ludwig Herzog of IMMS. The photo, taken after one hour intense grilling, shows a pretty happy Ms. Naujokat between her highly satisfied supervisor, and with our colleague Jörg König on the far left who served as the head of the diploma examination commission.

We wish Ms. Dipl.-Ing. Ina Naujokat much success in her upcoming PhD studies at TU Ilmenau, where she will further continue to specialize in the field of Precision Engineering.