On the wake in the low-Reynolds-number flow behind an impulsively started circular cylinder

This analysis completes the authors' singular perturbations type of solution of the title problem, when the cylinder acquires instantaneously a uniform velocity. As reported the solution consists of three expansions which represent the flow in three different space-time subdomains. It is shown here that there exists a fourth subdomain. An appropriate additional expansion is developed and matched with the other three. This latter expansion represents the flow late in the process in a wake region. This wake extends all the way downstream to infinity. Its width is comparable to the diameter of the obstacle.