Angel Terziev is a Professor of Fluid Mechanics at the Technical University of Sofia, Sofia, Bulgaria. He obtained his undergraduate degree in Heating technology from the Technical University of Sofia. He received his Ph.D. in Fluid Mechanics from the same university in 2007. In 2009, he was appointed as an Assistant Professor in the Department of Power Engineering and Power Machines at the Technical University of Sofia. He was promoted to Full Professor in 2023. From 2022, he has held the position of Dean of the Faculty of Power Engineering and Power Machines. His expertise is in the fields of fluid mechanics, computational fluid mechanics, renewable energy resources, energy efficiency, and the circular economy. He conducted specializations in the fields of two-phase flows and systems, fuel technology, energy efficiency, and renewable energy resources in Germany, Greece, Romania, and the USA. He has also served as a guest lecturer at EPMI, France; Polytechnic Bucharest, Romania; Karaganda University, Kazakhstan; and Almaty University, Kazakhstan. He is the Team Leader for bilateral contracts with Bulgarian and foreign universities, including Erasmus+. He is also part of the reviewer committee of the following journals: Energy, Energies, Symmetry, and Renewable Energy. He is the author of more than 200 scientific publications, more than 55 of which are indexed in Scopus. He has developed over 300 business plans related to improving energy efficiency.