The author clearly defines the test, the test environment, and the steady-state criterion, performs the measurements according to the success criteria, and transparently quantifies the deviations for each test case.

The main strengths are the well-justified simplifications of the experimental model compared with the flight model, the realistic interpretation of the results without overstating them, and the author’s own contribution in the form of the P–ΔT characterization curve, the secondary thermal resistance of 0.57 K/W, and the COP of 0.43.

The results are internally consistent across five runs and five power points, with a reasonably narrow spread of Rth values.

The thesis also has several weaknesses. The declared comparison between simulation and measurement is missing, meaning that the main result lacks an external reference, although it is internally verified through repeated measurements. There is also an error in the external heat flux calculation: the correct value should be approximately 16,468 W/m² rather than 1,646.8 W/m², which weakens the conclusion regarding the primary interface.

The main results are sufficiently supported internally, and I recommend the thesis for defense with a grade of A. Points proposed by supervisor: 90

The thesis resulted in a physically built and tested engineering model, EM1, supported by integration photographs, wiring documentation, five real test runs with measured temperature curves, a final characterization curve, a secondary thermal path resistance of approximately 0.57 K/W, and a COP of 0.43.

From an industrial-practice perspective, this is a strong outcome because the work is based on realization and measurement rather than simulation alone. All four assignment points are demonstrably fulfilled: the test and deviations from the flight environment are defined, the engineering model and its simplifications are justified, the tests are performed and supported by data, and the weak points and possible improvements are identified. The work is especially valuable for its honest treatment of the failed steady-state condition in PBT#1, its realistic and physically credible results, its practical handling of boundary conditions in the test setup, and its clear documentation of the measurement chain and integration.



The characterization curve is based on one sample and one run per point, without uncertainty propagation, thermocouple calibration, or statistical repeatability, which would be insufficient for a mission-level thermal budget. The heatsink operation and convection estimate also remain only approximately verified, with a wide range of possible cooling performance. Nevertheless, these issues do not undermine the fact that the model was built, operated, measured, and documented in a practically useful way.

The thesis is therefore recommended with a grade of 89 points Topics for thesis defence:

1. In Tables 5.4 and 5.5 (PDF pp. 65, 67), the product U·I does not correspond to the stated input power. For example, for PBT#4 TEC1: 14.51 V × 5.508 A = 79.9 W, whereas 36.4 W is reported. In addition, the current of 5.508 A exceeds the range of the KORAD KA3005DS power supply (0–5 A). How were these values obtained, and what current actually flowed through the TEC?

Points proposed by reviewer: 89