Mathematical modeling of viscous gas flow in a doubly connected volume with perforated walls

A numerical method is proposed for computing viscous gas flow in an initial doubly connected domain which is a volume having perforated walls and enclosing a sphere. The types of subdomains (finite volumes) into which the initial domain can be divided are considered. For each type of finite volume, there is a curvilinear coordinate system. Results of flow computation for $\mathrm{Re}=100$ and $500$, and $\mathrm{M}=0.6$ are given.