  The present study reports on flow past airfoils (stationary and moving) using
sharp interface immersed-boundary approach. Non-boundary conforming approach
like immersed-boundary method offers a viable alternative over traditional
boundary conforming approach by allowing us to model flow past arbitrarily
complex shapes, by eliminating the need to re-grid the flow domain as the body
exhibits motion. We present flow past a NACA 0012 airfoil at stationary
conditions as well as exhibiting pitching motion. Evolution of vortex dynamics
and wake structures are presented to show that the developed sharp interface
immersed-boundary approach captures the flow physics of dynamic stall
accurately. Moving body problems involving immersed-boundary approach usually
encounter the issues of spurious oscillations and mass conservation. This is
handled through a field extension strategy based on ghost cell approach, which
allows for extrapolating the flow field value onto the ghost nodes, ensuring
smooth temporal transition as the immersed surface moves through time. The
results presented here show excellent agreement with the experimental results
found in the literature.
