In September, Ing. Kryštof Mráz and Ing. Jiří Hvožďa successfully defended their doctoral theses at the Faculty of Mechanical Engineering, Brno University of Technology, under the supervision of Assoc. Prof. Jan Boháček, Ph.D. Both researchers conducted their work within the HeatLab, focusing on advanced thermal systems and polymeric materials for energy-efficient applications.
Ing. Kryštof Mráz defended his dissertation titled Optimization of Polymeric Hollow Fiber Heat Exchangers Using the Lattice Boltzmann Method.
His research dealt with the optimization of polymeric hollow fiber heat exchangers, which represent an innovative alternative to conventional metal heat exchangers. Due to the complex geometry of their heat transfer surface, their design process often relies on experiments rather than predictive modeling. In his thesis, Mráz compared two computational approaches — the finite volume method and the lattice Boltzmann method — for simulating flow and heat transfer inside these exchangers. He developed and verified a numerical model in OpenFOAM and conducted a parametric study using the concept of Pareto fronts to identify design parameters that balance high thermal performance with minimal pressure losses. The study provides valuable insights into the computational design of polymeric heat exchangers and demonstrates the potential of the lattice Boltzmann method for engineering optimization tasks.
Ing. Jiří Hvožďa defended his dissertation titled Polymeric Heat Exchangers: The Turning Point in Battery Thermal Management Systems.
His work focused on the thermal management of Li-ion batteries, with an emphasis on systems designed for electric vehicles. The research explored polymeric-based heat exchangers as a lightweight, electrically non-conductive, and environmentally sustainable alternative to aluminum components commonly used in battery cooling systems. Hvožďa developed a novel computational approach to model fully anisotropic thermal conductivity, implemented through user-defined functions in C. Furthermore, he proposed a rapid numerical method to predict the maximal temperature of battery cells with significantly reduced computational time. His work also introduced a concept of a perforated compensating film designed to homogenize temperature distribution, achieving up to a 36% reduction in temperature gradients. The results demonstrate the feasibility and advantages of polymeric heat exchangers for efficient and sustainable battery cooling in future electric vehicles.
Both dissertations highlight the growing importance of polymeric materials and numerical modeling in modern thermal engineering. Their outcomes contribute to the ongoing efforts of HeatLab to develop innovative, sustainable, and high-performance technologies for energy and environmental applications.
Congratulations to both new PhD graduates on the successful completion of their studies and defenses. Their work represents an important step forward in the field of heat and mass transfer research.