23/06/2020

Two state exams and one final defence of PhD thesis were taken on 4th April in Heat Transfer and Fluid Flow Laboratory. His thesis came to defend Martin Zachar. Tereza Kroulíková and Ondřej Resl came to pass the state doctoral exam.

Martin Zachar focused on ‘Use of Thermally Conductive Non-metallic Materials for Cooling Systems in Automotive Lighting Technology’. The thesis deals with the use of non-metallic highly thermally conductive materials, more concretely special plastic materials, enriched with highly thermally conductive additives, for the purpose of passive cooling of a given heat source. The thesis compares the effectivity of these heat sinks with the classically used materials, specifically aluminium. The thesis was supervised by associate professor Petr Kotrbáček.

Tereza Kroulíková has the thesis ‘Effect of a Tension on Pressure Drop Across the Flexible Bank of Polymeric Hollow Fibres in Crossflow’. The thesis is focused polymeric hollow fibre heat exchangers that have even more than thousand of fibres and their usage is not only in applications which need clean and anticorrosion materials, but also in applications where low weight is needed. For design of heat exchangers is important heat transfer and also the pressure drop. Since the pump power needed depends on the pressure drop. Common pressure drop relations for bank of tubes in crossflow used in engineering are derived from big rigid metal tubes. When those relations are used for small flexible polymeric hollow fibres, in some cases there is not a concordance with reality. The predicted values are underestimated. The thesis is supervised by Dr. Milan Hnízdil.

Ondřej Resl has the thesis ‘The Influence of Remaining Water and Other Significant Factors on Cooling Intensity during Heat Treatment of Steel’. His theasis is focused on the influence of factors on cooling during heat treatment of steel. Because the cooling process is very complex (many factors influence the cooling), there are still problems that can lead to undesirable changes in mechanical and physical properties of the final products or can cause their deformation. One of the factors, which significantly influences the cooling, is remaining water accumulating on the cooled surface. The thesis is supervised by associate professor Michal Pohanka.

All the exams were successfully passed. Congratulations to Dr Martin Zachar, Tereza Kroulíková and Ondřej Resl. We Wish them great success in the future.