NACA-TN-2463

Abstract

An experimental investigation has been made of the pressure distribution about a circular cylinder at yaw angles of 0°, 15°, 30°, 45°, and 60° for Reynolds numbers from below the critical value up to about 5.0 X l0⁵. The Reynolds number is based on the cylinder diameter and the component of velocity normal to the leading edge of the cylinder. The Mach number of the flow normal to the cylinder was less than 0.2 for all tests. The results of the investigation indicated that, for the range of Reynolds number near and above the critical value, the flow and force characteristics of a yawed circular cylinder cannot be determined only by the component of flow normal to the axis of the cylinder. For example, the critical Reynolds number decreased from 3.65 x l0⁵ for the unyawed cylinder to 1.00 X l0⁵ for the 60° yawed cylinder, and the supercritical drag coefficient, based on the flow normal to the leading edge of the cylinder, increased from approximately 0.18 for 0° yaw to approximately 0.74 for 60° yaw. In addition, the localized regions of laminar separation that appeared in the supercritical range of Reynolds number on the unyawed cylinder were not as well defined at yaw angles of 15 ° and 30 ° and completely disappeared at yaw angles of 45° and 60°.