Professor Subhasish Dey is a hydraulician and educator. He received BE degree in civil engineering from the University of North Bengal in 1981, and MTech and PhD degrees from the Indian Institute of Technology Kharagpur in 1984 and 1992, respectively. He is currently a Professor of the Department of Civil Engineering, Indian Institute of Technology (IIT) Kharagpur. He also holds the Adjunct Professor position in the Physics and Applied Mathematics Unit at Indian Statistical Institute Kolkata (2014–19) and the Distinguished Visiting Professor of Tsinghua University position in the Department of Hydraulic Engineering, Tsinghua University, Beijing, China (2016–19). He served as the Head of the Department of Civil Engineering during 2013–15 and held the position of Brahmaputra Chair Professor, IIT Kharagpur during 2009–14 and 2015 (April–September).
Academic and Research Achievements: Professor Dey has primarily contributed to develop fundamental theories and concepts of various hydrodynamic phenomena including many solution methodologies of various problems on applied hydrodynamics. Some of his contributions in recent years, comprising of both theoretical and sophisticated experimental researches, are as follows: First of all, Professor Dey’s very recent discovery of the origin of the scaling laws of particle motion due to small-scale turbulent eddies arising from the phenomenology of turbulent energy cascade is a ground breaking contribution (2017, Proc. A Royal Society London). He also discovered the origin of the onset of meandering a straight river from the viewpoint of turbulent phenomenological concept (2017, Proc. A Royal Society London). These discoveries have opened a new direction in fluvial hydrodynamic research (2018, Phys. Fluids). His theory on advection-diffusion of suspended particle motion by turbulence in a wall-shear flow considering the turbulent kinetic energy flux has changed the existing understanding of the phenomenon of suspended particle motion (2016, Proc. A Royal Society London). Besides, his research has huge impacts on practical engineering and field applications, especially in fluvial hydrodynamics. In this field, he developed a quasi-deterministic theory (2016, Phys. Fluids) and as well as a stochastic theory (2017, Phys. Fluids) of particle entrainment due to turbulent flow. His contribution to hydrodynamic instability of a meandering channel provided a strong insight to the complex phenomenon of a meandering channel migration (2017, Phys. Fluids). Then, the most elegant experimental study by Professor Dey and his team on the offset jet flow provided an improved understanding on the self-preserving flow characteristics in jet flow (2016, Phys. Fluids). Besides, experimental and numerical studies on turbulence laws in natural and artificial bed flows are pertinent to mention (2016, 2018, J. Fluid Mech.). Dey-Ali theory of “particle scale of entrainment to continuum scale of bedload flux” throws new light in fluvial hydrodynamics (2017, ASCE J. Eng. Mech.). He developed a novel theory of turbulent flow over a wavy boundary (2016, J. Hydraul. Eng.) and advanced a theoretical model for the entry flow in curved pipes aided by turbulent boundary layer approach (2016, J. Hydraul. Res.). A detailed hydrodynamic analysis of fully‐developed turbidity currents over plane beds based on self‐preserving velocity and concentration distributions is another remarkable contribution (2015, J. Geophys. Res., Earth Surface). He also analysed turbulent length scales and Reynolds stress anisotropy downstream of a wall mounted sphere (2015, J. Hydraul. Res.). He is the first to apply Reynolds averaged approach to solve gravity waves on turbulent shear flow (2014, J. Hydraul. Eng.). Professor Dey has published over 170 research articles in peer-reviewed journals and authored a book (2014, Fluvial Hydrodynamics, Springer, Germany), that has become a key source for the students (graduate and research level) and professionals all over the world.
Other Contributions: Professor Dey is an associate editor of the Journal of Hydraulic Engineering (ASCE), Journal of Hydraulic Research (IAHR), Sedimentology, Acta Geophysica, Journal of Hydro-Environment Research, International Journal of Sediment Research and Journal of Numerical Mathematics and Stochastics. He is also an editorial board member of several journals including the Proceedings of the Royal Society of London A: Mathematical, Physical and Engineering Sciences. He is a council member of IAHR (2015–19), member of IAHR Fluvial Hydraulics Committee (2014–), a past-council member of the World Association for Sedimentation and Erosion Research (WASER), Beijing (2010–13), and a Foreign Expert in China (2016–18).
Awards and Honours: Professor Dey is a fellow of the Indian Academy of Sciences (FASc) (2012), the National Academy of Sciences India (FNASc) (2012) and Indian National Academy of Engineering (FNAE) (2008). He received the JC Bose Fellowship award in 2018.