The Von-Karman vortex street flow behind a circular cylinder issuccessfully solved at R_e=100 for incompressible N-S equations in theform of stream function and vorticity.The method adopted here involvesADI-BGE schemes,a recent treatment of body boundary conditions anda new acceptable perturbation model.The solutions of the flow fieldobtained here are better than previous numerical ones and agree with theexperimental data closer.Therefore,it can be used to study sound fieldnumerically.The Curle equation is directly and numerically solved to ana-lyze the distribution of sound sources and the characteristics of their radi-ated sound field at R_e=100 and to compare with the solution fromthe theory of vortex sound.It is shown that this method is successful. The Von-Karman vortex street flow behind a circular cylinder issuccessfully solved at R_e = 100 for incompressible NS equations in the form of stream function and vorticity. The method incorporated here involves ADI-BGE schemes, a recent treatment of body boundary conditions and a new acceptable perturbation model The solutions of the flow fieldobtained here are better than previous numerical ones and agree with the experimental data closer.Therefore, it can be used to study sound fieldnumerically. The Curle equation is directly and numerically solved to ana-lyze the distribution of sound sources and the characteristics of their radi-ated sound field at R_e = 100 and to compare with the solution from the theory of vortex sound. It is shown that this method is successful.