Jat du Toit is an emeritus professor of Mechanical Engineering and the emeritus DSI/NRF SARChI Research Chair in Nuclear Engineering at the North-West University, Potchefstroom, South Africa. He obtained a B.Eng. (Hons.)(Civil) and a M.Eng. (Civil) from the University of Stellenbosch and a Ph.D. from the University of Cambridge. He has published more than 100 papers in international and national journals and conference proceedings and was the co editor of the proceedings of two conferences. He is a registered professional engineer with practical experience in the fields of civil, mechanical, chemical, metallurgical, and nuclear engineering and focuses on the numerical modeling of thermal-fluid processes. He is a partner of the commercial engineering software development and consulting firm M-Tech Industrial which develops and markets the system CFD code Flownex. His current interests are the development of advanced thermal-fluid simulation models for high-temperature gas-cooled nuclear reactors and associated cooling systems using a systems CFD approach. He has been a senior technical consultant for the Pebble Bed Modular Reactor (PBMR) project. Along with his colleagues, he has made contributions to the influence of the packing structure of pebble bed on the thermal-hydraulic phenomena, as well as the interaction between the reactor unit and the reactor cavity cooling system for pebble bed reactor and prismatic block reactor-based systems.