Abstract
A thrown boomerang flies along an arch path and returns to the thrower. The flying motion is a complex motion caused by the gyroscopic precession which is the coupled phenomenon of air-flow and boomerang-motion. In this study, the flying motion of the boomerang was demonstrated using the numerical simulation and we showed influences of the figure of the boomerang on the flying motion of the boomerang. In the numerical simulation, we combined Moving-Grid Finite-Volume Method for fluid-flow solver, the Forward-Euler Finite-Difference Method for body-motion solver and the Quaternion for representation of body-rotation to solve the coupled phenomenon of air-flow and boomerang-motion. The moving-grid finite-volume method is constructed based on four-dimensional control volume in which space and time are unified and assures strictly both physical conservation laws and geometric conservation laws. The motion equation with six degrees of freedom was solved in a coupled manner together with the Navier-Stokes equations. Furthermore, the experiment was performed to validate the computational results and the computational results showed good agreement with the experimental results. In addition, it was shown that the angle of wing’s flap and the angle of incidence have great effect on the path of the boomerang.
