The Forces acting on Two Circular Cylinders of arbitrary Radii placed in a Uniform Stream at Low Values of Reynolds Number

Abstract

The steady slow motion of a viscous fluid past two parallel circular cylinders C₁, C₂ of arbitrary radii is discussed on the basis of Oseen’s linearized equations of motion, confining ourselves to the case when their axes are perpendicular to a uniform flow. The forces acting on the cylinder C₁ are calculated to the first approximation.
By performing detailed numerical calculations, a discussion is made on the manner in which the forces acting on the cylinder C₁ is modified by the presence of the other cylinder C₂.
It is thus found that, as the radius of the cylinder C₂ increases, the drag on the cylinder C₁ decreases, while the lift increases. It is also found that the cylinder C₁ experiences smaller drag when the two cylinders are in tandem orientation than when they are placed side by side in a uniform stream. Especially, when the cylinder C₁ is situated behind the cylinder C₂, it experiences smaller drag than when it is situated in front of C₂.