PA – Investigation of the thermomechanical behavior of power modules under cryogenic cooling

This project thesis focuses on the simulation-based investigation of the thermo-mechanical behavior of a double-sided cooled power module utilizing GaN HEMTs, intended for use in electric aircraft propulsion systems.

A key aspect of the study is the design for cryogenic coolant temperatures below –150 °C, as encountered when using liquid nitrogen. At such temperatures, many materials exhibit significantly altered thermal and mechanical properties. Therefore, careful material selection is essential. Existing data and prior knowledge will serve as a foundation for this evaluation. A material model for indium, available in literature, will be used as a starting point for simulations.

Based on a given power module concept, various design ideas for the required spacers will be analyzed using finite element method (FEM) simulations. These concepts will be assessed both in terms of their thermal performance and their impact on the overall mechanical integrity of the power module. To support this investigation an automated simulation workflow will be developed using PyAnsys.

The results will be used to identify critical design parameters and derive quantitative design recommendations to improve the reliability of cryogenically cooled GaN-based power modules for electric aviation applications.

Bearbeiter: Muhil Kumar Saravanan

Betreuer: Julius Zettelmeier (LEE), Prof. Martin März

Verantwortlicher:  Prof. Dr.-Ing. Martin März