Abstract
This paper reports on numerical simulations of the flow around an accelerating circular cylinder by means of Large Eddy Simulation in a noninertial boundary fitted coordinate system. Simulations with different acceleration patterns were performed. twin vortex was observed in the cylinder wake during acceleration for all the cases. This twin voltex is not obserrved for the corresponding Reynolds numbers under the steady state without acceleration Time evolution of drag coefficient is different from that predicted by the quasi-steady assumption. Under a high acceleration, the drag coefficient shows a time evolution similar to the coefficient predicted by added mass, which is not the case when the cylinder acceleration is relatively low.