The aerodynamic drag and axial rotation of an arrow

Abstract

The down-range behaviour of arrows has a strong influence on an archer’s ability to obtain good scores. A major input to that performance is the arrow’s aerodynamic drag. A wide variety of arrow types are available, and within each type there are a number of sizes and combinations of the various component parts of the arrow. Consequently the drag can be expected to vary significantly from arrow to arrow. In addition, the arrow’s fletching is usually set at an angle to the shaft’s longitudinal axis, causing the arrow to spin in order to minimize inaccuracies due to, for example, arrow straightness variation, and this will also affect the down-range behaviour. This paper provides a means of calculating the arrow’s drag and axial spin, and uses that to compare predicted down-range velocity with that measured for three quite different, but representative arrows. The method is compared with methods developed by Rheingans and Liston.