Advances in Direct Simulation Monte Carlo: From Micro-Scale to Rarefied Flow Phenomena

Ehsan Roohi is currently a visiting associate professor at Embry Riddle Aeronautical University, Daytona Beach. In September 2025, he will join the Mechanical and Industrial Engineering Department at the University of Massachusetts Amherst. He received his Ph.D. degree from the Department of Aerospace Engineering, Sharif University of Technology, Tehran, Iran, in 2010, with a sabbatical visit at the University of Strathclyde, Uk. He was a University Professor at the Ferdowsi University of Mashhad, Iran and Xi’an Jiaotong University, China. He worked at the University of Maryland, School of Medicine, and the Department of Mechanical Engineering at Johns Hopkins in 2023-2024. He is an expert in direct simulation Monte Carlo (DSMC) techniques and has published several papers on new collision models in DSMC. His research primarily involves utilizing numerical models to explore rarefied gas dynamics in outer space and at micro and nano scales. He developed new propulsion systems for spacecraft, benefiting from solar radiation. He published more than 130 journal papers in prestigious journals such as Journal of Fluid Mechanics, Journal of Computational Physics, and Physics of Fluids. 

Dr. Hassan Akhlaghi received his B.Sc., M.Sc., and Ph.D. in Aerospace Engineering from Sharif University of Technology, Tehran, Iran, in 2007, 2010, and 2020, respectively. Since Sep. 2024, Dr. Akhlaghi has been an assistant professor in the Faculty of New Science and Technology, University of Tehran. Dr. Akhlaghi focuses on the research of rarefied gas dynamics and micro-/nano-scale gas flows. His research interests include rarefied gas flows simulation using the DSMC method, algorithm development in the DSMC method, gas flow investigation in microchannels, flow physics of rarefied gas flows, etc. Since 2008, Dr. Akhlaghi has published 42 peer-reviewed technical papers in international journals and conferences. He served as a reviewer for several international journals. He was awarded the top Researcher Award, which recognized his achievement as one of the most highlighted research outputs performed by Sharif University of Technology in 2019–2020. 

Dr. Stefan Stefanov is a professor at the Institute of Mechanics, Bulgarian Academy of Sciences, Sofia, Bulgaria. He received a Doctor of Science in Applied Mathematics from Sofia University in 1987. Prof. Stefanov is interested in topics including microfluidics, kinetic theory of gases, fluid mechanics, flow instabilities, self-organized fluid systems, transition to turbulence, partial differential equations, numerical methods in fluid mechanics, and Monte Carlo numerical methods (with particular interest in the Direct Simulation Monte Carlo (DSMC) method).