Unidirectional motion using rotating masses along figure-eight-shaped trajectories

Abstract

This paper revisits the notorious Dean’s drive, aiming at causing unidirectional motion when attached to an object at rest (inertial propulsion). Instead of the usual circular path along which lumped eccentric masses move, a novel figure-eight-shaped curve is proposed. It is generally shown that the rotational kinetic energy accumulated in the rotating masses produces an equivalent linear ‘initial’ velocity to the object, and therefore, it further works like an oscillating projectile within the gravitational field. Conditions for the variation of the angular velocity, in order to achieve a ‘very short-time hovering’, are derived. The study does not consider any elastodynamic effects and reduces only to rigid-body analysis. Further improvements such as the spinning of the entire mechanism about its axis of symmetry are discussed.