urgent !

Anand

Hi, Im using FLUENT to perform a simulation of aerodynamically generated sound past a 2D circular cylinder. Why do i need to use the unsteady model? what are the distances the cylinder has to be from the lateral boundaries ? how do i know if the flow has converged oir not and that the solution i obtained is correct? what does the drag and force coefficients do and how do i know if these coefficients i get is correct? i am new with fluent so i really need some help !

Thanks ! Looking forward to hear from you all