Afshin J. Ghajar is Emeritus Regents Professor and John Brammer Endowed Professor in the School of Mechanical and Aerospace Engineering at Oklahoma State University, Stillwater, Oklahoma, USA and an Honorary Professor of Xi’an Jiaotong University, Xi’an, China. He received his B.S., M.S., and Ph.D. degrees all in mechanical engineering from Oklahoma State University. His expertise is in experimental heat transfer/fluid mechanics and development of practical engineering correlations. He is a Fellow of the American Society of Mechanical Engineers (ASME) and the American Society of Thermal and Fluids Engineers (ASTFE). He is a Registered Professional Engineer in the State of Oklahoma. Professor Ghajar has received countless teaching/service awards, such as the 75th Anniversary Medal of the ASME Heat Transfer Division, the ASME ICNMM Outstanding Leadership Award, and the Donald Q. Kern Award, among others. His research work has resulted in over 250 publications including professional journals, reports, books, peer-reviewed conference papers or symposium proceedings. His research achievements have also been documented by a large number of presentations as well as keynote and invited lectures all over the world. A 2020 study conducted by Ionnidis et al. of Stanford University [Updated science-wide author databases of standardized citation indicators (plos.org)], ranked nearly 160,000 scientists of all disciplines based on citations to their work over their career and for the year 2019, Professor Ghajar ranked in the top 1.3% of researchers in Mechanical Engineering and Transports category. He currently serves as the Editor-in-Chief of Heat Transfer Engineering Journal and is the Heat Transfer Series Editor for CRC Press (he has edited 13 books to date). He is the co-author of two popular textbooks, Heat and Mass Transfer – Fundamentals and Applications, 6th Edition (2020), and Fundamentals of Thermal-Fluid Sciences, 6th Edition (2022), both published by McGraw-Hill; and the author of Two-Phase Gas-Liquid Flow in Pipes with Different Orientations, Springer Briefs in Applied Sciences and Technology, published by Springer 2020, and Single- and Two-Phase Flow Pressure Drop and Heat Transfer in Tubes, Mechanical Engineering Series, published by Springer, 2022.

Gretar Tryggvason is the Charles A. Miller, Jr. Distinguished Professor at the Johns Hopkins University and the head of the Department of Mechanical Engineering. He received his PhD from Brown University in 1985 and was on the faculty of the University of Michigan in Ann Arbor until 2000, when he moved to Worcester Polytechnic Institute as the head of the Department of Mechanical Engineering. Between 2010 and 2017 he was the Viola D. Hank professor at the University of Notre Dame and the chair of the Department of Aerospace and Mechanical Engineering. Professor Tryggvason is well known for his contributions to computational fluid dynamics; particularly the development of methods for computations of multiphase flows and for pioneering direct numerical simulations of such flows. He served as the editor-in-chief of the Journal of Computational Physics 2002-2015, is a fellow of APS, ASME and AAAS, and the recipient of several awards, including the 2012 ASME Fluids Engineering Award and the 2019 ASTFE Award.