Wing-wake interaction leads to an increase in lift. Clap and fling produces higher lift at low Reynolds number (unfavorable aerodynamic conditions i.e. low lift to drag ratio) as compared to hovering and is therefore employed by most small insects. The gap between wings and percentage overlap between translation and rotation are further identified as additional parameters that influence lift. This work has been published in Physics of Fluids (2014).

A translating discontinuous-grid-block model for moving boundaries has been developed. It is shown that the implementation of a body-fitted refined mesh that moves along with the object reduces the spurious oscillations registered in the force and velocity measurements compared to a single coarse grid block. The proposed technique offers significant advantage in terms of capturing flow around moving solids at lower computational cost and simulation time as compared to the stationary discontinuous-grid-block method. This work has been published in Computers and Fluids (2016) and I received SICTP Gold award for this work.

This work is directed towards characterizing the fluid mechanics associated with a self-propelled-heaving rigid flat plate in a quiescent medium and helps us to understand how a flapping wing moves forward from rest. Through surrogate modeling, a set of Pareto-optimal solutions that describe the tradeoff between efficiency and input power for forward flight is presented and offers insight into the design and development of next generation flapping wing micro-air vehicles. This work has been published in Journal of Fluids and Structures (2016).

This work is directed towards understanding the role of passive flexion for a plunging plate leading to thrust generation and transverse locomotion. To mimic a real flapping insect wing, a fluid–structure interaction framework based upon a generalized two-dimensional lumped-torsional flexibility model for a multi-component system was developed. Flexibility was implemented in a discrete sense at a finite number of locations along the length of the plate with intermediate rigid sections connected to each other through torsion springs. This work has been published in Journal of Fluid Mechanics (2018).

A particle fluid interaction numerical framework comprising of combined discrete element - lattice Boltzmann method (DEM-LBM) is developed to examine the electrorheological (ER) behavior in a converging/diverging channel. The flow direction in funnel plays a crucial role in enhancing ER effect. The hydrodynamic rectification (defined as the ratio of the pressure drop in the forward to reverse direction) is expected to be an order of magnitude as shown in simulations here. In addition, the behavior of alternating electric field on ER effect is also investigated.

The competence of my flow solver is further enhanced to simulate complex turbulent flow setups in three-dimensions and has been generalized for any arbitrary stationary or moving geometry with multi-levels of grid refinement. Validations have been conducted for the benchmark cases against the state of the art turbulence modelling techniques such as large eddy simulations (LES) and high-order spectral element direct numerical simulations (DNS). The simulations shown here are computationally very expensive and were run on 1000 cores.