DrDipanjan Majumdar

Dipanjan is a Post-Doctoral Research Associate in the Fluid Mechanics section at the Department of Civil and Environmental Engineering, Imperial College London, working with Prof. Maarten van Reeuwijk. His research work, funded by the EPSRC ExCALIBUR project “Turbulence at the Exascale: Application to Wind Energy, Green Aviation, Air Quality and Net-zero Combustion”, focuses on enhancing the parallel efficiency of the uDALES a large-eddy simulation model for urban environments, to run on large-scale heterogeneous computers. The primary area of application has been the urban microclimate simulations, specifically looking at vegetation (tree) modelling in computational fluid dynamic (CFD) simulations of built environment.

Dipanjan's research interests encompass urban fluid mechanics, unsteady aerodynamics, nonlinear dynamics, computational fluid & structural dynamics, high performance computing on CPU and GPUs, and related fields. He earned his B. E. in Mechanical Engineering with first class honours from Jadavpur University, Kolkata, India, followed by an M. S. & Ph. D. from the Department of Aerospace Engineering, Indian Institute of Technology Madras, Chennai, India. At IIT Madras, he worked in the Biomimetics and Dynamics Laboratory under the guidance of Prof. Sunetra Sarkar, where his Ph. D. thesis focused on the dynamical transition in the unsteady wake of bio-inspired flapping foils in the low Reynolds number regime. During Ph. D., he developed an in-house unsteady Navier-Stokes solver (FSIS-IBM) in C++ language, employing the discrete forcing immersed boundary method (IBM). For high performance computation, the code was parallelized using OpenMP and OpenACC techniques. The in-house flow solver was combined with an elastic structural model to simulate coupled fluid-structure interaction (FSI) dynamics. Later, he made significant contribution towards developing a high-fidelity FSI solver by coupling the IBM solver with a finite difference method based structural solver to look at the coupled dynamics of highly flexible filament-like structures with application to biological systems. He studied the dynamical characteristics of the flow-field past a flapping foil for a diverse set of kinematic and profile parameters to identify the key vortex interaction mechanism responsible for the periodic-to-chaotic transition, and presented an order-to-chaos map with generalized transition boundaries demarcating the different dynamical regimes. He further looked into the role of passive pitch on altering these dynamical behaviours, and also inspecting the gust mitigating capabilities of flapping foils. He explored the effects of stochastic inflow fluctuation on the jet-switching in the wake of a flapping foil and reported the underlying vortex interaction mechanism behind jet-switching.