Shengyao Jiang is a Full Professor and Director of the Key Laboratory of Advanced Reactor Engineering and Safety at Tsinghua University. He is also the Vice Chairman of the University Council and Vice Chairman of the Multiphase Flow Committee, Chinese Society of Engineering Thermophysics. He obtained his doctorate from Stuttgart University, Germany, in 1995. Prof. Jiang has received seven Scientific & Technological Awards from the Ministry of Education, former National Defense Science and Industry Commission, and China Nuclear Industry Group Corporation. He has published over 300 papers, supported by the National Science Foundation for Outstanding Youth Project. He is one of the EICs of Experimental and Computational Multiphase Flow. Jiyuan Tu is a Professor at the School of Engineering, RMIT University, and a China National 1000 Top-Talent Program Distinguished Professor at Tsinghua University. He obtained his doctorate in computational fluid dynamics from the Royal Institute of Technology, Sweden, in 1992. His research interests include subcooled flow boiling; spray cooling; biomedical engineering; fluid–structure interaction; aerosol deposition in human airways and nasal cavities; and blood flow in arteries. Prof. Tu has published 10 books and over 500 papers, with over 6000 total citations. Xingtua Yang is a Full Professor at the Institute of Nuclear and New Energy Technology (INET), Tsinghua University, and Director of INET’s Thermal Hydraulics Division. Holding a doctorate from Tsinghua University, he has published over 200 papers and is especially known for his contributions to experimental and computational research in nuclear engineering. Nan Gui is a Professor at the Thermal Hydraulics Division, Institute of Nuclear and New Energy Technology (INET), Tsinghua University. Having completed his doctorate at Zhejiang University in 2010, his research interests include reactor thermal hydraulics, pebble bed flows and heat transfer; computational multiphase flows, e.g., fluidized beds, swirling flows, jet flows, etc.; and particle flow/granular flows, e.g., drum mixers, gravity-driven flows, mixing and heat conduction, etc. He has published over 70 SCI-indexed papers and received China’s 100 National Excellent Doctoral Dissertations Award.

• Introduction.- Experiments in pebble flows.- Experiments in pebble bed heat transfer.- Numerical Simulation and Analysis for pebble flows.- Numerical models for pebble bed heat transfer.- Applications: Two-region Pebble beds.- Applications: Pebble flow optimizations.- Applications: Complex pebble flows.- Future research issues and recommendations.