Head of laboratory:

dr. Jure RAVNIK, professor of power process and environmental engineering, 
web: http://jure.ravnik.si E-mail: jure.ravnik@um.si  phone.: +386 2 220 7745, 
Open source effort: https://github.com/transport-phenomena


The Transport Phenomena in Solids and Fluids Laboratory is part of the Mechanical Engineering Research Institute at the Faculty of Mechanical Engineering of the University of Maribor. We are engaged in researching the nature of phenomena that include the transfer of energy, matter and momentum. We use our knowledge to design and implement solutions in the field of energy, process and environmental engineering. The core of our work is the development of numerical models and simulation tools for the broader field of computational fluid dynamics. We develop our own solutions and at the same time upgrade and modify commercial or open source tools with the aim of achieving highly accurate and extremely powerful simulations in the field of transport phenomena.



  • Development of user-adapted mathematical-physical models in the field of process and environmental engineering
  • Custom upgrade of commercial or open source simulation software solutions in process and environmental engineering
  • Training in the field of computational fluid dynamics, efficient use of high-performance computer equipment and efficient and automated evaluation of simulation results and experimental measurements
  • Implementation of simulations and optimization of engineering solutions in the field of power, process and environmental engineering



Investigations of the behavior of inhaled droplets in the human respiratory tract.

During the development of the Covid pandemic, we responded and contributed to the understanding of droplet deposition in the human respiratory tract. We investigated the influence of activity level, age, room size and compared the behavior of exhaled droplets with the behavior of droplets produced by sneezing and coughing. 

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Development of models for the simulation of non-spherical particles in flows.

In process and environmental engineering, we encounter problems involving the motion of non-spherical particles in fluids. With the aim of improving the understanding of the behavior of such particles and creating new simulation tools, we have developed a model that enables the prediction of forces and torques that act on non-spherical particles in flows.

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Development of new numerical algorithms based on the boundary element method.

Transport phenomena include the transfer of energy, matter and momentum. The correct prediction of the transfer phenomenon in engineering devices is the key basis for achieving a high-quality optimization of machines and devices that exploit these phenomena. Our work in the development of numerical methods is focused on providing highly accurate results by incorporating physical laws into the numerical algorithm itself.

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Simulations and development of models to understand the flow of nanofluids.

Nanofluids are stable suspensions of very small metal oxide particles suspended in a carrier liquid. With a slightly increased viscosity, such fluids have very good thermal properties. When used as a heat transfer medium they surpass the classic fluids that are in use today. Our research in this area mainly covers the development of new models and the upgrading of simulation tools, which enable a more accurate prediction of the flow itself and the transfer of heat in devices that use nanofluids.

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Stochastic methods for assessing the accuracy of simulation results.

Traditional simulation tools are deterministic and as such do not allow the accuracy of simulation results to be assessed. We have developed a stochastic tool with the help of which we can determine the accuracy of simulations and at the same time determine the strength of the influence of individual parameters on the results. This allows engineers to be aware of the shortcomings of the simulation and at the same time they can identify the parameters that need to be addressed first during the optimization process.

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ARIS program: P2-0196 Research in power, process and environmental engineering 

ARIS projects:


International projects: 

  • DFG research project: A numerical model for translational and rotational momentum transfer of soft deformable micro particles in dilute two-phase flows, 2023 - 2026
  • BI-TR/22-24-05 : Evaluation of nanofluid modeling strategies in natural convection heat exchangers, 2022 – 2024
  • BI-CN/20-22-002 Analysis of the deposition of aerosol droplets inhaled using a nebulizer in the human respiratory tract, 2021 – 2023
  • DFG research project: A numerical model of translational and rotational momentum transfer of small non-spherical rigid particles in fluid dominated two-phase flows, 2018 - 2022
  • COST Innovators Grants (CIG): NANOConVEX, https://nanoconvex.eu/, 2021-2022
  • COST NANOUPTAKE Overcoming Barriers to Nanofluids Market Uptake CA15119, http://www.nanouptake.eu/, 2017-2021
  • BI-HR/18-19-010 Development of a method for coupled simulation of fluid flow and bioelectromagnetic phenomena, 2018 – 2019
  • BI-UA/09-10-011 Development of a fast boundary element method for use in fluid mechanics, 2013 – 2014
  • BI-US/15-16-038 Simulation of nanofluids using the boundary element method, 2015 - 2016