Interactive flow around a circular cylinder controlled by a small rod

Abstract

In this paper, a unique flow control method using a small rod, called the forced reattachment method, is proposed for the control of the flow around a bluff body. As described in previous papers, the forced reattachment method is a type of separated shear layer control that reduces drag and generates lift, and it can only occur under certain conditions. The forced reattachment phenomenon occurs as a result of an interactive flow between a circular cylinder and a small rod. This phenomenon is characterized by many special features, such as a large stagnant region behind the circular cylinder and the reattachment flow, which adheres to the rear face of the circular cylinder. It is also interesting how it reduces the total drag, including that of the small rod. The aim of this study was to elucidate the details of the stagnant region, the properties of the reattachment flow, and the reduction of the total drag.