@article{oai:nagoya.repo.nii.ac.jp:00030664, author = {Nakamura, Ikuo and Watanabe, Takashi and Yoshida, Takashi}, issue = {1}, journal = {Memoirs of the School of Engineering, Nagoya University}, month = {Oct}, note = {The issue of open, or outflow, boundary conditions is important to the numerical simulation of incompressible viscous flows. But there are few studies of this problem because it is very difficult to give exact mathematical conditions for finite and artificial boundaries. In this paper, four types of open boundary conditions are compared numerically in a two-dimensional flow past a square cylinder using a finite difference method. They are a free outflow condition and three kinds of Sommerfeld radiation conditions based on the free stream velocity at infinity, the Halpern's analysis, and the local velocity. The free outflow condition deforms velocity and pressure fields, while the Sommerfeld radiation condition using the free stream velocity has the least influence on the flow.}, pages = {105--117}, title = {On the numerical outflow boundary condition of the viscous flow around a square cylinder}, volume = {45}, year = {1993} }