Axisymmetric stagnation flow obliquely impinging on a circular cylinder

Laminar stagnation flow, axisymmetrically yet obliquely impinging on the generators of a circular cylinder, is formulated as an exact solution of the Navier-Stokes equations. The outer stream is composed of a rotational axial flow superposed onto irrotational radial stagnation flow normal to the cylinder. The relative importance of these two flows is measured by a parameter gamma. The viscous problem is reduced to a coupled pair of ordinary differential equations governed by a Reynolds number R introduced by Wang (1974). Two-term. asymptotic formulae valid for large R are derived for the wall shear stress and for the position and slope of streamline attachment. These results agree well with exact numerical calculations for R > 30. In checking the consistency of our solution in the planar limit R --> infinity we uncover and correct an error in the work of Dorrepaal (2000) for the position of viscous streamline attachment. (C) 2003 Editions scientifiques et medicales Elsevier SAS. AN rights reserved.