Host: The Japan Society of Mechanical Engineers
Name : Mechanical Engineering Congress,Japan
Date : September 11, 2016 - September 14, 2016
The aerodynamic properties of an archery arrow (A/C/E; Easton) have been investigated by extending our previous work, in which the laminar-turbulent transition of the boundary layer on the arrow shaft were found to take place in the Re number range 1.3×104 < Re < 1.8×104. In this paper, we focus on the influence of arrow attitude on the transition. Two support-interference-free tests were carried out to provide the aerodynamic properties, such as the drag, lift and pitching moment coefficients. The static aerodynamic properties were measured in a wind tunnel with JAXA's 60cm Magnetic Suspension and Balance System.. Secondly, free flight experiments were performed. The arrow’s trajectory and attitude were recorded using four high-speed video cameras. By analyzing the recorded images, we obtained the initial and final velocities, from which the drag coefficient was determined. The trajectory and attitude of the arrow were computed numerically by integrating the equations of motion of rigid body, using the initial data obtained from the video images. The laminar-turbulent transition of the boundary layer taken place, if the maximum angle of attack exceeds about 0.5°at Re=1.8×104. The influence of the flexural oscillation of an arrow is also discussed.
