Numerical Flow Calculation based on Velocity Integrals on Boundary. 2nd Report, Calculation of Flow around a Circular Cylinder and Review of Calculation Method.

Two-dimensional incompressible viscous flow calculation has been presented. Flow field has been divided into small sub-domains. Vorticity and vortical velocity distributions in the sub-domain have been calculated using BEM (boundary element method) similar to Wu's method, and then vortical velocity has been superposed with potential flow to obtain overall flow field. Effects of vorticity distribution outside of sub-domain boundary have been taken into consideration in calculations based on velocity integrals on boundary. Vorticity diffusion has been treated as transient potential flow problems by BEM. The transport of vortices has been considered as the instantaneous vortex source distributed in the flow field. Calculations of viscous flow around a circular cylinder at moderate Reynolds numbers 1000 and 1200 have been presented. Merits of using sub-domains in the case of sparse but large-sized matrices have been explained.